Glossary of nautical terms

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This is a partial glossary of nautical terms; some remain current, while many date from the 17th to 19th centuries. See also Wiktionary's nautical terms, Category:Nautical terms, and Nautical metaphors in English. See the Further reading section for additional words and references.

A foresail when against the wind, used when tacking to help the vessel turn.[1]
Toward the stern, relative to some object ("abaft the fore hatch").
Abaft the beam
Further aft than the beam: a relative bearing of greater than 90 degrees from the bow: "two points abaft the beam, starboard side". That would describe "an object lying 22.5 degrees toward the rear of the ship, as measured clockwise from a perpendicular line from the right side, center, of the ship, toward the horizon."[2]
Abandon ship!
An imperative to leave the vessel immediately, usually in the face of some imminent overwhelming danger.[3] It is an order issued by the Master or a delegated person in command. (It must be a verbal order). It is usually the last resort after all other mitigating actions have failed or become impossible, and destruction or loss of the ship is imminent; and customarily followed by a command to "man the lifeboats" or life rafts.[3][4]
On the beam, a relative bearing at right angles to the ship's keel.[5]
Able seaman
Also able-bodied seaman. A merchant seaman qualified to perform all routine duties, or a junior rank in some navies.
On or in a vessel. Synonymous with "on board." (See also close aboard.)
Above board
On or above the deck, in plain view, not hiding anything. Pirates would hide their crews below decks, thereby creating the false impression that an encounter with another ship was a casual matter of chance.[7]
Above-water hull
The hull section of a vessel above the waterline, the visible part of a ship. Also, topsides.
Absentee pennant
Special pennant flown to indicate absence of commanding officer, admiral, his chief of staff, or officer whose flag is flying (division, squadron, or flotilla commander).
Absolute bearing
The bearing of an object in relation to north. Either true bearing, using the geographical or true north, or magnetic bearing, using magnetic north. See also bearing and relative bearing.
Accommodation ladder
A portable flight of steps down a ship's side.
Accommodation ship (or accommodation hulk)
A ship or hulk used as housing, generally when there is a lack of quarters available ashore. An operational ship can be used, but more commonly a hulk modified for accommodation is used.
Act of Pardon or Act of Grace
A letter from a state or power authorising action by a privateer. See also Letter of marque.
Action Stations
See Battle stations.
Senior naval officer of Flag rank. In ascending order of seniority, Rear Admiral, Vice Admiral, Admiral and (until about 2001 when all UK five-star ranks were discontinued) Admiral of the Fleet (Royal Navy). Derivation Arabic, from Amir al-Bahr ("Ruler of the sea").
2.  Admiralty law
Admiralty law
Body of law that deals with maritime cases. In the UK administered by the Probate, Divorce and Admiralty Division of the High Court of Justice or supreme court.
1.  Afloat and unattached in any way to the shore or seabed, but not under way. When referring to a vessel, it implies that the vessel is not under control and therefore goes where the wind and current take her (loose from moorings or out of place).
2.  Any gear not fastened down or put away properly.
3.  Any person or thing that is misplaced or missing. When applied to a member of the navy or marine corps, such a person is "absent without leave" (AWOL) or, in US Navy and US Marine Corps terminology, is guilty of an "unauthorized absence" (UA).[8]
Advance note
See aviso.
Of a vessel which is floating freely (not aground or sunk). More generally of vessels in service ("the company has 10 ships afloat").
1.  In, on, or toward the front of a vessel.
2.  In front of a vessel.
1.  The portion of the vessel behind the middle area of the vessel.
2.  Towards the stern (of the vessel).[1]
1.  On larger ships, a secondary gangway rigged in the area aft of midship. On some military vessels, such as US Naval vessels, enlisted personnel below E-7 board the ship at the afterbrow; officers and CPO/SCPO/MCPO board the ship at the brow.[9]
Afternoon watch
The 1200–1600 watch.
Resting on or touching the ground or bottom (usually involuntarily).
Forward of the bow.
A cry to draw attention. Term used to hail a boat or a ship, as "Boat ahoy!"
1.  Lying broadside to the sea.
2.  To ride out a storm with no sails and helm held to leeward.
Aid to Navigation
1.  (ATON) Any device external to a vessel or aircraft specifically intended to assist navigators in determining their position or safe course, or to warn them of dangers or obstructions to navigation.
2.  (ATON) Any sort of marker which aids the traveler in navigation; the term is most commonly used to refer to nautical or aviation travel. Common types of such aids include lighthouses, buoys, fog signals, and day beacons.
Aircraft carrier
A warship designed with a primary mission of deploying and recovering aircraft, acting as a seagoing airbase. Frequently shortened to carrier, since 1918, the term generally has been limited to a warship with an extensive flight deck designed to operate conventional fixed-wing aircraft. In United States Navy slang, also called a flat top or a bird farm.
1.  On the lee side of a ship.
2.  To leeward.
All hands
Entire ship's company, both officers and enlisted personnel.
All night in
Having no night watches.
All standing
Bringing a person or thing up short, that is an unforeseen and sudden stop.[8]
A term used in maritime law – To impact a stationary object (not submerged), such as a bridge abutment or dolphin, pier or wharf, or another vessel made fast to a pier or wharf. More than incidental contact is required, the vessel is said to "allide" with the fixed object and is considered at fault. As opposed to collision.
In the rigging of a sailing ship. Above the ship's uppermost solid structure; overhead or high above.
1.  In the rigging of a sailing ship.
2.  Above the ship's uppermost solid structure.
3.  Overhead or high above.
By the side of a ship or pier.
The middle section of a vessel with reference to the athwartships plane, as distinguished from port or starboard ("Put your rudder amidships." (Compare Midships.))
Ammunition ship
A naval auxiliary ship specifically configured to carry ammunition, usually for naval ships and aircraft.
1.  an object designed to prevent or slow the drift of a ship, attached to the ship by a line or chain; typically a metal, hook-like or plough-like object designed to grip the bottom under the body of water (but see also sea anchor).
2.  to deploy an anchor ("She anchored offshore.")
Anchor ball
Round black shape hoisted in the forepart of a vessel to show that it is anchored.
Anchor buoy
A small buoy secured by a light line to an anchor to indicate position of anchor on bottom.
Anchor chain (or anchor cable)
Chain connecting the ship to the anchor.
Anchor detail
Group of men who handle ground tackle when the ship is anchoring or getting under way.
Anchor home
When the anchor is secured for sea. Typically rests just outside the hawsepipe on the outer side of the hull, at the bow of a vessel.
Anchor light
Anchor rode
The anchor line, rope or cable connecting the anchor chain to the vessel. Also Rode.
Anchor sentinel
A separate weight on a separate line which is loosely attached to the anchor rode so that it can slide down it easily. It is made fast at a distance slightly longer than the draft of the boat, it is used to prevent the anchor rode from becoming fouled on the keel or other underwater structures when the boat is resting at anchor and moving randomly during slack tide. Also called a kellet.
Anchor watch
The crewmen assigned to take care of the ship while anchored or moored, charged with such duties as making sure that the anchor is holding and the vessel is not drifting. Most marine GPS units have an Anchor Watch alarm capability.
Anchor winch
Horizontal capstan in the bow used for weighing anchor.[1]
A suitable place for a ship to anchor. Area of a port or harbor.
Anchor's aweigh
Said of an anchor when just clear of the bottom.
Traditional lower-deck slang term for the Royal Navy.
The expected response of a vessel to control mechanisms, such as a turn answering to the wheel and rudder. "She won't answer" might be the report from a helmsman when turning the wheel under a pilot's order fails to produce the expected change of direction.
Anti-rolling tanks
A pair of fluid-filled, usually water, tanks mounted on opposite sides of a ship below the waterline. The tanks are cross linked by piping or ducts to allow water to flow between them and at the top by vents or air pipes, the piping would be sized so that as the fluid flowed from side to side it dampened the amount of roll.


More or less vertical. Having the anchor rode or chain as nearly vertical as possible without freeing the anchor.

Over to the port side.
Apparent wind
Arc of visibility
The plank along the stern where the name of the ship is commonly painted.
A ship's weapons.
Articles of War
Regulations governing the military and naval forces of UK and US; read to every ship's company on commissioning and at specified intervals during the commission.
As the crow flies
A direct line between two points (which might cross land) which is the way crows travel rather than ships which must go around land. See also Great circle
Purportedly an acronym. A type of sonar used by the Allies for detecting submarines during the First and Second World War. abbreviation: Allied Submarine Devices Investigation Committee (World War I). The term has been generically applied to equipment for "under-water supersonic echo-ranging equipment" of submarines and other vessels.[10]
1.  On the beach, shore, or land (as opposed to aboard or on board).
2.  Towards the shore.
3.  "To run ashore": To collide with the shore (as opposed to "to run aground," which is to strike a submerged feature such as a reef or sandbar)
Over to the starboard side.
1.  Toward the stern (rear) of a vessel.
2.  Behind a vessel.
Astern gear
The gear or gears which, when engaged with an engine or motor, result in backwards movement or force. Equivalent to reverse in a manual-transmission automobile.
Asylum harbour
A harbour used to provide shelter from a storm. See "Harbor of refuge."
Anti-submarine warfare.
Athwart, athwartships
At right angles to the fore and aft or centerline of a ship.
Auxiliary ship (or auxiliary)
A naval ship designed to operate in any number of roles supporting combatant ships and other naval operations, including a wide range of activities related to replenishment, transport, repair, harbor services, and research.
Stop, cease or desist from whatever is being done. From the Dutch hou' vast ("hold on"), the imperative form of vasthouden ("to hold on to") or the Italian word "Basta"[8] Compare ¡Ya basta!
Aviso (formerly also an adviso)
A kind of dispatch boat or advice boat, survives particularly in the French navy, they are considered equivalent to the modern sloop.
So low in the water that the water is constantly washing across the surface.
Position of an anchor just clear of the bottom.
Axial fire
Fire oriented towards the ends of the ship; the opposite of broadside fire. In the age of sail this was known as 'raking' fire.
Aye, aye /ˌ ˈ/
Reply to an order or command to indicate that it, firstly, is heard; and, secondly, is understood and will be carried out. ("Aye, aye, sir" to officers). Also the proper reply from a hailed boat, to indicate that an officer is on board.
Azimuth circle
Instrument used to take bearings of celestial objects.
Azimuth compass
An instrument employed for ascertaining position of the sun with respect to magnetic north. The azimuth of an object is its bearing from the observer measured as an angle clockwise from true north.


B & R rig
A style of standing rigging used on sailboats that lacks a backstay. The mast is said to be supported like a "tripod," with swept-back spreaders and a forestay. Used widely on Hunter brand sailboats, among others. Designed and named by Lars Bergstrom and Sven Ridder and protected by US Patent number 3866558, dated February 18, 1975.
Back and fill
To use the advantage of the tide being with you when the wind is not.
Long lines or cables, reaching from the stern of the vessel to the mast heads, used to support the mast.
A soft covering for cables (or any other obstructions) that prevents sail chafing.
A device for removing water that has entered the boat.
Heavy material that is placed in the hold of a vessel to provide stability. (See also in ballast.)
Ballast tank
A device used on ships and submarines and other submersibles to control buoyancy and stability.
Balls to four watch
The 0000–0400 watch. (US Navy)
A large area of elevated sea floor.
Traditional Royal Navy term for a day or shorter period of rest and relaxation.
Large mass of sand or earth, formed by the surge of the sea. They are mostly found at the entrances of great rivers or havens, and often render navigation extremely dangerous, but confer tranquility once inside. See also: touch and go, grounding. Alfred Lord Tennyson's poem "Crossing the bar" is an allegory for death.
Bar pilot
A bar pilot guides ships over the dangerous sandbars at the mouth of rivers and bays.
Barber hauler
A technique of temporarily rigging sailboat lazy sheet allowing the boat to sail closer to the wind. i.e. Using the lazy jib sheet to pull the jib closer to the mid line, allowing a point of sail that would otherwise not be achievable.
[citation needed]
1.  During the second half of the 19th century, a fixed armored enclosure protecting a ship's guns aboard warships without gun turrets, generally taking the form of a ring of armor over which guns mounted on an open-topped rotating turntable could fire.
2.  Since the late 19th century, the inside fixed trunk of a warship's turreted gun-mounting, on which the turret revolves, containing the hoists for shells and cordite from the shell-room and magazine.
A two- or three-masted lugger used for fishing on the coasts of Spain and Portugal and more widely in the Mediterranean Sea in the late 17th century and 18th century. The British Royal Navy also used them for shore raids and as dispatch boats in the Mediterranean.
Bareboat charter
An arrangement for the chartering or hiring of a vessel, whereby the vessel's owner provides no crew or provisions as part of the agreement; instead, the people who rent the vessel are responsible for crewing and provisioning her.
1.  A towed or self-propelled flat-bottomed boat, built mainly for river, canal, and coastal transport of heavy goods.
2.  Admiral's barge: A boat at the disposal of an admiral for his or her use as transportation between a larger vessel and the shore or within a harbor.
Alternative spelling of barque.
Alternative spelling of barquentine.
Barque (also bark)
A sailing vessel of three or more masts, with all masts but the sternmost square-rigged, the sternmost being fore-and-aft-rigged.
Barquentine (also barkentine)
A sailing vessel with three or more masts; with a square-rigged foremast and all other masts fore-and-aft rigged.
Barrack ship
A ship or craft designed to function as a floating barracks for housing military personnel.
A sailor that was stationed in the crow's nest.
1.  A stiff strip used to support the roach of a sail, enabling increased sail area.
2.  Any thin strip of material (wood, plastic etc) which can be used any number of ways
Batten down the hatches
To prepare for inclement weather by securing the closed hatch covers with wooden battens so as to prevent water from entering from any angle.
Battle Stations (also: general quarters, action stations)
1.  An announcement made aboard a naval warship to signal the crew to prepare for battle, imminent damage, or a damage emergency (such as a fire).
2.  Specific positions in a naval warship to which one or more crew are assigned when battle stations is called.
A type of large capital ship of the first half of the 20th century, similar in size, appearance, and cost to a battleship and typically armed with the same kind of heavy guns, but much more lightly armored (on the scale of cruiser) and therefore faster than a battleship but more vulnerable to damage.
A type of large, heavily armored warship of the second half of the 19th century and first half of the 20th century armed with heavy-caliber guns, designed to fight other battleships in a line of battle. It was the successor to the ship-of-the-line of the Age of Sail.
Deliberately running a vessel aground to load and unload (as with landing craft), or sometimes to prevent a damaged vessel sinking.
A lighted or unlighted fixed aid to navigation attached directly to the earth's surface. (Lights and daybeacons both constitute beacons.)
1.  The ram on the prow of a fighting galley of ancient and medieval times.
2.  The protruding part of the foremost section of a sailing ship of the 16th to the 18th century, usually ornate, used as a working platform by sailors handling the sails of the bowsprit. It also housed the crew's heads (toilets).
The width of a vessel at the widest point, or a point alongside the ship at the midpoint of its length.
Beam ends
The sides of a ship. "On her beam ends" may mean the vessel is literally on her side and possibly about to capsize; more often, the phrase means the vessel is listing 45 degrees or more.
Beam reach
Sailing with the wind coming across the vessel's beam. This is normally the fastest point of sail for a fore-and-aft rigged vessel.
Beam sea
A sea where waves are moving perpendicular to the direction a ship is moving
Beam wind
A wind at right angles to the vessel's course.
Large squared off stone used with sand for scraping clean wooden decks.
Bear away
To steer (a vessel) away from the wind.[1]
Bear down or bear away
Turn away from the wind, often with reference to a transit.
Bear up
Turn into the wind.[1]
The horizontal direction of a line of sight between two objects on the surface of the earth. See also absolute bearing and relative bearing.
Beat to quarters
Beating or Beat to
Sailing as close as possible towards the wind (perhaps only about 60°) in a zig-zag course to attain an upwind direction to which it is impossible to sail directly.(also tacking)
Beaufort scale
The scale describing wind force devised by Admiral Sir Francis Beaufort in 1808, in which winds are graded by the effect of their force (originally, the amount of sail that a fully rigged frigate could carry).
To cut off the wind from a sailing vessel, either by the proximity of land or by another vessel.
Unable to move due to lack of wind; said of a sailing vessel.
Before the mast
Literally, the area of a ship before the foremast (the forecastle). Most often used to refer to men whose living quarters are located here, officers being quartered in the stern-most areas of the ship (near the quarterdeck). Officer-trainees lived between the two ends of the ship and become known as "midshipmen". Crew members who started out as seamen, then became midshipmen, and later, officers, were said to have gone from "one end of the ship to the other". (See also hawsepiper.)
1.  To make fast a line around a fitting, usually a cleat or belaying pin.
2.  To secure a climbing person in a similar manner.
3.  An order to halt a current activity or countermand an order prior to execution.
Belaying pins
Short movable bars of iron or hard wood to which running rigging may be secured, or belayed.
A type of buoy with a large bell and hanging hammers that sound by wave action.[citation needed] (See also ship's bell.)
On or into a lower deck, e.g., The captain has gone below.
Below decks
In or into any of the spaces below the main deck of a vessel.
Belt armor
A layer of heavy metal armor plated onto or within the outer hulls of warships, typically on battleships, battlecruisers, cruisers, and aircraft carriers, usually covering the warship from her main deck down to some distance below the waterline. If built within the hull, rather than forming the outer hull, the belt would be installed at an inclined angle to improve the warship's protection from shells striking the hull.
1.  A knot used to join two ropes or lines. See also hitch.[1]
2.  To attach a rope to an object[1]
3.  Fastening a sail to a yard[11]
Bermuda rig or Bermudan rig
A triangular mainsail, without any upper spar, which is hoisted up the mast by a single halyard attached to the head of the sail. This configuration, introduced to Europe about 1920, allows the use of a tall mast, enabling sails to be set higher where wind speed is greater.
Bermuda sloop
A fore-and-aft rigged sailing vessel with Bermuda rig developed in Bermuda in the 17th century. In its purest form, it is single-masted, although Bermuda sloops can have up to three masts, three-masted ships being referred to as schooners. Originally gaff rigged, but evolved to use Bermuda rig, the Bermuda sloop is the basis of nearly all modern sailing yachts.
Berth (moorings)
A location in a port or harbour used specifically for mooring vessels while not at sea.
Berth (navigation)
Safety margin of distance to be kept by a vessel from another vessel or from an obstruction, hence the phrase, "to give a wide berth."[12]
Berth (sleeping)
A bed or sleeping accommodation on a boat or ship.
Best bower (anchor)
The larger of two anchors carried in the bow; so named as it was the last, best hope.
Between the devil and the deep blue sea
See devil seam.
Between wind and water
Bight /bt/
1.  Bight, a loop in rope or line – a hitch or knot tied on the bight is one tied in the middle of a rope, without access to the ends.[1]
2.  An indentation in a coastline.
Bilander (also billander or be'landre)
a small European merchant sailing ship with two masts, the mainmast lateen-rigged with a trapezoidal mainsail, and the foremast carrying the conventional square course and square topsail. Used in the Netherlands for coast and canal traffic and occasionally in the North Sea, but more frequently used in the Mediterranean Sea.
1.  The compartment at the bottom of the hull of a ship or boat where water collects and must be pumped out of the vessel. The space between the botton hull planking and the ceiling of the hold.[1]
2.  To spring a leak in the bilge.
3.  To break open a vessel′s bilge.
Bilge keels
Bilged on her anchor
A ship that has run upon her own anchor, so the anchor cable runs under the hull.
The extremity of the arm of an anchor; the point of or beyond the fluke.
Bimini top
Open-front canvas top for the cockpit of a boat, usually supported by a metal frame.
A punitive instrument
The stand on which the ship's compass is mounted.
Binnacle list
A ship's sick list. The list of men unable to report for duty was given to the officer or mate of the watch by the ship's surgeon, the list was kept at the binnacle.
Bird farm
United States Navy slang for an aircraft carrier (q.v.).
Verb used in reference to a rudder, as in "the rudder begins to bite." When a vessel has steerageway the rudder will act to steer the vessel, i.e. it has enough water flow past it to steer with. Physically this is noticeable with tiller or unassisted wheel steering by the rudder exhibiting resistance to being turned from the straight ahead – this resistance is the rudder "biting" and is how a helmsman first senses that the vessel has acquired steerageway.
Bitt or bitts
1.  A post or pair mounted on the ship's bow, for fastening ropes or cables.
2.  Strong vertical timbers or irons fastened through the deck beams used for securing ropes or hawsers.[1]
Bit heads
The tops of two massive timbers that support the windlass on a sailing barge.[1]
Bitter end
The last part or loose end of a rope or cable. The anchor cable is tied to the bitts; when the cable is fully paid out, the bitter end has been reached.
Black gang
The engineering crew of the vessel, i.e., crew members who work in the vessel's engine room, fire room, and boiler room, so called because they would be covered in coal dust during the days of coal-fired steamships.
A pulley with one or more sheaves (grooves), over which a rope is roved. It can be used to chage the direction of the rope, or in pairs used to form a tackle.[1]
A vessel sunk deliberately to block a waterway to prevent the waterway′s use by an enemy.
Blue Ensign
A flag flown as an ensign by certain British ships. Prior to 1864, ships of the Royal Navy′s Blue Squadron flew it; since the reorganisation of the Royal Navy in 1864 eliminated its naval use, it has been flown instead by 1) British merchant vessels whose officers and crew include a certain prescibed number (which has varied over the years) of retired Royal Navy or Royal Naval Reserve personnel or which are commanded by an officer of the Royal Naval Reserve in possession of a Government warrant, 2) Royal Research Ships by warrant, regardless of their manning by naval, naval reserve, and Merchant Navy personnel, or 3) British-registered yachts belonging to members of certain yacht clubs, although yachts were prohibited from flying the Blue Ensign during World War I and World War II.
Blue Peter
A blue and white flag (the flag for the letter "P") hoisted at the foretrucks of ships about to sail. Formerly a white ship on a blue ground, but later a white square on a blue ground.
1.  To step onto, climb onto, or otherwise enter a vessel.
2.  The side of a vessel.
3.  The distance a sailing vessel runs between tacks (q.v.) when working to windward (q.v.).
1.  A small craft or vessel designed to float on, and provide transport over, or under, water.
2.  Naval slang for a submarine of any size.
Boat hook
A pole with blunt tip and a hook on the end, sometimes with a ring on its opposite end to which a line may be attached. Typically used to assist in docking and undocking a boat, with its hook used to pull a boat towards a dock and the blunt end to push it away from a dock, as well as to reach into the water to people catch buoys or other floating objects or to reach people in the water.
Boatswain or bosun (both /ˈbsən/)
A non-commissioned officer responsible for the sails, ropes, rigging and boats on a ship who issues "piped" commands to seamen.
Boatswain's call, also bosun's call, boatswain's pipe, bosun's pipe, boatswain's whistle, or bosun's whistle
A high-pitched pipe or a non-diaphragm-type whistle used on naval ships by a boatswain, historically to pass commands to the crew but in modern times limited to ceremonial use.
Boatswain's chair or bosun's chair
A short board or swatch of heavy canvas, secured in a bridle of ropes, used to hoist a man aloft or over the ship's side for painting and similar work. Modern boatswain's chairs incorporate safety harnesses to prevent the occupant from falling.
Boatswain's pipe
See boatswain's call.
Boatswain's whistle
See boatswain's call.
A maker of boats, especially of traditional wooden construction.
Bob or bobfly
A pennant or flag bearing the owner's colours, mounted on the Topsail trunk [1]
A stay which holds the bowsprit downwards, counteracting the effect of the forestay and the lift of sails. Usually made of wire or chain to eliminate stretch.[1]
Body plan
In shipbuilding, an end elevation showing the contour of the sides of a ship at certain points of her length.
Boiler room
See fire room.
Bolt rope
A rope, sewn on to reinforce the edges of a sail.[1]
From "bol" or "bole", the round trunk of a tree. A substantial vertical pillar to which lines may be made fast. Generally on the quayside rather than the ship.
Bombay runner
Large cockroach.
Bonded jacky
A type of tobacco or sweet cake.
A strip of canvas secured to the foot of the course (square sail) to increase sail area in light airs.
A type of bird that has little fear and therefore is particularly easy to catch.
Booby hatch
A sliding hatch or cover.
Boom (navigational barrier)
A floating barrier to control navigation into and out of rivers and harbours.
Boom (sailing)
A spar attached to the foot of a fore-and-aft sail.
Slang term in the US Navy for a ballistic missile submarine.
Boom gallows
A raised crossmember that supports a boom when the sail is lowered (obviates the need for a topping lift).
Boomie or Booms'l rig
A ketch rigged barge with gaff (instead of spritsail) and boom on main and mizzen. Booms'l rig could also refer to cutter rigged early barges.[1]
Boom vang or vang
A sail control that lets one apply downward tension on a boom, countering the upward tension provided by the sail. The boom vang adds an element of control to sail shape when the sheet is let out enough that it no longer pulls the boom down. Boom vang tension helps control leech twist, a primary component of sail power.
See bumpkin.
Masts or yards, lying on board in reserve.
Bore, as in Bore up or Bore away
To assume a position to engage, or disengage, the enemy ship(s)
See boatswain.
Bosun's call
See boatswain's call.
Bosun's chair
See boatswain's chair.
Bosun's pipe
See boatswain's call.
Bosun's whistle
See boatswain's call.
A device for adjusting tension in stays, shrouds and similar lines.[1]
1.  The underside of a vessel; the portion of a vessel that is always underwater.
2.  A ship, most often a cargo ship.
3.  A cargo hold.
Pledging a ship as security in a financial transaction.
1.  The front of a vessel.
2.  Either side of the front (or bow) of the vessel, i.e., the port bow and starboard bow. Something ahead and to the left of the vessel is "off the port bow", while something ahead and to the right of the vessel is "off the starboard bow." When "bow" is used in this way, the front of the vessel sometimes is called her bows (plural), a collective reference to her port and starboard bows synonymous with bow (singular) as described in Definition (1).
Bow chaser
See chase gun
1.  A type of knot, producing a strong loop of a fixed size, topologically similar to a sheet bend.[1]
Also a rope attached to the side of a sail to pull it towards the bow (for keeping the windward edge of the sail steady).[1].  {{{content}}}
Also a rope attached to the foresail to hold it aback when tacking.[1].  {{{content}}}
The person, in a team or among oarsmen, positioned nearest the bow
To pull or hoist.
A spar projecting from the bow used as an anchor for the forestay and other rigging. On a barge it may be pivoted so it may be steeved up in harbour.[1]
Bow thruster
A small propeller or water-jet at the bow, used for manoeuvring larger vessels at slow speed. May be mounted externally, or in a tunnel running through the bow from side to side.
Boxing the compass
To state all 32 points of the compass, starting at north, proceeding clockwise. Sometimes applied to a wind that is constantly shifting.
Boy Seaman
a young sailor, still in training
Brace abox
To bring the foreyards flat aback to stop the ship.
To furl or truss a sail by pulling it in towards the mast, or the ropes used to do so. To brail up – to stow the sails.[1]
The handle of the pump, by which it is worked.
Brass monkey or brass monkey weather
Used in the expression "it is cold enough to freeze the balls off a brass monkey."
Brass pounder
Early 20th-century slang term for a vessel's radio operator, so called because he repeatedly struck a brass key on his transmitter to broadcast in Morse code.
Break bulk cargo (or breakbulk cargo)
Goods that must be loaded aboard a ship individually, and not in intermodal containers or in bulk, carried by a general cargo ship.
1.  A structure constructed on a coast as part of a coastal defense system or to protect an anchorage from the effects of weather and longshore drift.
2.  A structure built on the forecastle of a ship intended to divert water away from the forward superstructure or gun mounts.
Breeches buoy
A ring lifebuoy fitted with canvas breeches, functionally similar to a zip line, used to transfer people from one ship to another or to rescue people from a wrecked or sinking ship by moving them to another ship or to the shore.
A structure above the weather deck, extending the full width of the vessel, which houses a command centre, itself called by association, the bridge.
Bridge wing
An open-air extension of the bridge to port or starboard, intended for use in signaling.
1.  (historically) A vessel with two square-rigged masts.
2.  (in the US) An interior area of the ship used to detain prisoners (possibly prisoners-of-war, in war-time) and stowaways, and to punish delinquent crew members. Usually resembles a prison cell with bars and a locked, hinged door.
Brig sloop
A type of sloop-of-war introduced in the 1770s which had two square-rigged masts like a brig (in contrast to ship sloops of the time, which had three masts).
Brigantine (also hermaphrodite brig)
A two-masted vessel, square-rigged on the foremast, but fore-and-aft-rigged on the mainmast.
Exposed varnished wood or polished metal on a boat.
Bring to
Cause a ship to be stationary by arranging the sails.
When a sailing vessel loses control of its motion and is forced into a sudden sharp turn, often heeling heavily and in smaller vessels sometimes leading to a capsize. The change in direction is called broaching-to. Occurs when too much sail is set for a strong gust of wind, or in circumstances where the sails are unstable.
Wide (broad) in appearance from the vantage point of a lookout or other person viewing activity in the vicinity of a ship, e.g., another ship off the starboard bow with her side facing the viewer's ship could be described as "broad on the starboard bow" of the viewer's ship.
1.  One side of a vessel above the waterline.
2.  All the guns on one side of a warship or mounted (in rotating turrets or barbettes) so as to be able fire on the same side of a warship.
3.  The simultaneous firing of all the guns on one side of a warship or able to fire on the same side of a warship.
4.  Weight of broadside, the combined weight of all projectiles a ship can fire in a broadside, or the combined weight of all the shells a group of ships that have formed a line of battle collectively can fire on the same side.
See gangplank.
The chief bosun's mate (in the Royal Navy), responsible for discipline.
Bulbous bow
A protruding bulb at the bow of a ship just below the waterline which modifies the way water flows around the hull, reducing drag and thus increasing speed, range, fuel efficiency, and stability.
Bulk cargo
Commodity cargo that is transported unpackaged in large quantities.
Bulk carrier (also bulk freighter or bulker)
A merchant ship specially designed to transport unpackaged bulk cargo in its cargo holds.
An upright wall within the hull of a ship, particularly a watertight, load-bearing wall.
Bulwark or Bulward (/ˈbʊlək/ in nautical use)
Bulwark (or Bulward)
The extension of the ship's side above the level of the weather deck.

Bull ensign (also "boot ensign" or "George ensign")
The senior ensign (q.v.) of a US Navy command (i.e., a ship, squadron, or shore activity). The bull ensign assumes additional responsibilities beyond those of other ensigns, such as teaching less-experienced ensigns about life at sea, planning and coordinating wardroom social activities, making sure that the officers' mess runs smoothly, and serving as an officer for Navy-related social organizations, the bull ensign also serves as the focal point for the unit's expression of spirit and pride.
A private boat selling goods.
Bumpkin or boomkin
1.  A spar, similar to a bowsprit, but which projects from the stern. May be used to attach the backstay or mizzen sheets.
2.  An iron bar (projecting out-board from a ship's side) to which the lower and topsail brace blocks are sometimes hooked.
A container for storing coal or fuel oil for a ship's engine.
Bunker fuel or bunkers
Fuel oil for a ship.
Bunting tosser
A signalman who prepares and flies flag hoists. Also known in the American Navy as a skivvy waver.
One of the lines tied to the bottom of a square sail and used to haul it up to the yard when furling.
A floating object of defined shape and color, which is anchored at a given position and serves as an aid to navigation.
Buoyed up
Lifted by a buoy, especially a cable that has been lifted to prevent it from trailing on the bottom.
Burden (Early Modern English: Burthen, Middle English: Byrthen)
The Builder's Old Measurement, expressed in "tons bm" or "tons BOM", a volumetric measurement of cubic cargo capacity, not of weight. This is the tonnage of a ship, based on the number of tuns of wine that it could carry in its holds. One 252-gallon tun of wine takes up approximately 100 cubic feet – and, incidentally, weighs 2,240 lbs (1 long ton, or Imperial ton).
A small flag, typically triangular, flown from the masthead of a yacht to indicate yacht-club membership.
By and large
By means into the wind, while large means with the wind. "By and large" is used to indicate all possible situations "the ship handles well both by and large".
By the board
Anything that has gone overboard.


an enclosed room on a deck or flat.
Cabin boy
attendant on passengers and crew. often a young man
1.  A large rope.
2.  A cable length (q.v.).
Cable length
A measure of length or distance. Equivalent to (UK) 1/10 nautical mile, approx. 600 feet; (US) 120 fathoms, 720 feet (219 m); other countries use different values. Sometimes called simply a cable.
a small ship's kitchen, or galley on deck.
The transport of goods or passengers between two points in the same country, alongside coastal waters, by a vessel or an aircraft registered in another country.
Loaded vessels lashed tightly, one on each side of another vessel, and then emptied to provide additional buoyancy that reduces the draught of the ship in the middle.
1.  A type of navigational buoy often a vertical drum, but if not, always square in silhouette, colored red in IALA region A or green in IALA region B (the Americas, Japan, Korea and the Philippines). In channel marking its use is opposite that of a "nun buoy".
2.  A shortened version of tin can (q.v.).
Canal boat
A specialized watercraft designed for operation on a canal.
a type of antipersonnel cannon load in which lead balls or other loose metallic items were enclosed in a tin or iron shell. On firing, the shell would disintegrate, releasing the smaller metal objects with a shotgun-like effect.
Canoe stern
A design for the stern of a yacht which is pointed, like a bow, rather than squared off as a transom.
Cape Horn fever
The name of the fake illness a malingerer is pretending to suffer from.
Capital ship
A navy's most important warships, generally possessing the heaviest firepower and armor and traditionally much larger than other naval vessels, but not formally defined. During the Age of Sail, generally understood to be ships-of-the-line; during the second half of the 19th century and the 20th century, understood to be battleships and battlecruisers; and since the 1940s considered to include aircraft carriers. Since the second half of the 20th century, ballistic missile submarines sometimes have been considered capital ships.
When a ship or boat lists too far and rolls over, exposing the keel. On large vessels, this often results in the sinking of the ship. Compare Turtling, infra.
A large winch with a vertical axis. A full-sized human-powered capstan is a waist-high cylindrical machine, operated by a number of hands who each insert a horizontal capstan bar in holes in the capstan and walk in a circle. Used to wind in anchors or other heavy objects; and sometimes to administer flogging over.
1.  The person lawfully in command of a vessel. "Captain" is an informal title of respect given to the commander of a naval vessel regardless of his or her formal rank; aboard a merchant ship, the ship's master is her "captain."
2.  A naval officer with a rank between commander and commodore.
3.  In the US Navy, US Coast Guard, and National Oceanic and Atmospheric Administration Corps, a commissioned officer of a grade superior to a commander and junior to a rear admiral (lower half), equal in grade or rank to a US Army, US Marine Corps, or US Air Force colonel.
Captain of the Port
1.  In the United Kingdom, a Royal Navy officer, usually a captain, responsible for the day-to-day operation of a naval dockyard.
2.  In the United States, a US Coast Guard officer, usually a captain, responsible for enforcement of safety, security, and marine environmental protection regulations in a commercial port.
Captain's daughter
The cat o' nine tails, which in principle is only used on board on the captain's (or a court martial's) personal orders.
Car carrier
A cargo ship specially designed or fitted to carry large numbers of automobiles Modern pure car carriers have a fully enclosed, boxlike superstructure that extends along the entire length and across the entire breadth of the ship, enclosing the automobiles. The similar pure car/truck carrier also can accommodate trucks.
Car float (also railroad car float or rail barge)
An unpowered barge with railroad tracks mounted on its deck, used to move railroad cars across water obstacles.
Caravel (also caravelle)
A small, highly maneuverable sailing ship with lateen rig used by the Portuguese in the 15th and 16th centuries to explore along the West African coast and into the Atlantic Ocean.
Referring to the four main points of the compass: north, south, east and west. See also bearing.
Tilting a ship on its side, usually when beached, to clean or repair the hull below the water line. Also known as to "heave down".
Cargo ship
Any sort of ship or vessel that carries cargo, goods, and materials from one port to another, including general cargo ships (designed to carry break bulk cargo), bulk carriers, container ships, multipurpose vessels, and tankers. Tankers, however, although technically cargo ships, are routinely thought of as constituting a completely separate category.
1.  In the Age of Sail, a warrant officer responsible for the hull, masts, spars, and boats of a vessel, and whose responsibility was to sound the well to see if the vessel was making water.
2.  A senior rating responsible for all the woodwork aboard a vessel.
Carrack (also nau)
A three- or four-masted sailing ship used by Western Europeans in the Atlantic Ocean from the 15th through the early 17th century.
An aircraft carrier (q.v.).
A short, smoothbore, cast iron naval cannon, used from the 1770s to the 1850s as a powerful, short-range anti-ship and anti-crew weapon.
Carvel built
A method of constructing wooden hulls by fixing planks to a frame so that the planks butt up against each other. Cf. "clinker built".
1.  To prepare an anchor, after raising it by lifting it with a tackle to the cat head, prior to securing (fishing) it alongside for sea. (An anchor raised to the cat head is said to be catted.)
2.  The cat o' nine tails (see below).
3.  A cat-rigged boat or catboat.
Cat o' nine tails
A short nine-tailed whip kept by the bosun's mate to flog sailors (and soldiers in the Army). When not in use, the cat was kept in a baize bag, this is a possible origin for the term "cat out of the bag," though livestock trade was more likely[13] where this phrase came from. "Not enough room to swing a cat" also derives from this.
A vessel with two hulls.
A cat-rigged vessel with a single mast mounted close to the bow, and only one sail, usually on a gaff.
A short rope or iron clamp used to brace in the shrouds toward the masts so as to give a freer sweep to the yards.
A beam extending out from the hull used to support an anchor when raised in order to secure or 'fish' it.
Cats paws
Light variable winds on calm waters producing scattered areas of small waves.
Celestial Navigation
Navigation by the position of celestial objects including the stars, sun, and moon, using tools aboard ship such as a sextant, chronometer, and compass, and published tables of the position of celestial objects. Celestial Navigation was the primary method of navigation until the development of electronic global positioning systems such as LORAN and GPS.
1.  A lining applied to the interior of a hull for both aesthetic reasons and to bar or insulate the ship's cargo from the cold hull surface. Often made of thin strips of wood, attached horizontally with a small gap between to allow air flow to the interior hull surface.[1]
2.  The inside planking forming the floor of a barges hold; at the lining was carried up to the inwale.[1]
Center of effort (or centre of effort)
The point of origin of net aerodynamic force on sails, roughly located in the geometric center of a sail, but the actual position of the center of effort will vary with sail plan, sail trim or airfoil profile, boat trim, and point of sail. Also known as center (or centre) of pressure
Center of lateral resistance (or centre of lateral resistance)
The point of origin of net hydrodynamic resistance on the submerged structure of a boat, especially a sailboat. This is the pivot point about which the boat turns when unbalanced external forces are applied, similar to the center of gravity, on a balanced sailboat the center of effort should align vertically with the center of lateral resistance. If this is not the case the boat will be unbalanced and exhibit either lee helm or weather helm and will be difficult to control.
Centerline (or centerline)
An imaginary line down the center of a vessel lengthwise. Any structure or anything mounted or carried on a vessel that straddles this line and is equidistant from either side of the vessel is on the centerline (or centreline).
Centreboard (or centerboard)
A board or plate lowered through the hull of a dinghy on the centreline to resist leeway.
Wear on line or sail caused by constant rubbing against another surface.
Chafing gear
Material applied to a line or spar to prevent or reduce chafing. See Baggywrinkle.
Chain locker
A space in the forward part of the ship, typically beneath the bow in front of the foremost collision bulkhead, that contains the anchor chain when the anchor is secured for sea.
Cannon balls linked with chain used to damage rigging and masts.
Chain-wale or channel
A broad, thick plank that projects horizontally from each of a ship's sides abreast a mast, distinguished as the fore, main, or mizzen channel accordingly, serving to extend the base for the shrouds, which supports the mast.
Small platforms built into the sides of a ship to spread the shrouds to a more advantageous angle. Also used as a platform for manual depth sounding.
Charley Noble
The metal stovepipe chimney from a cook shack on the deck of a ship or from a stove in a galley.
A compartment, especially in the Royal Navy, from which the ship was navigated.
An electronic instrument which places the position of the ship (from a GPS receiver) onto a digital nautical chart displayed on a monitor, thereby replacing all manual navigation functions. Chartplotters also display information collected from all shipboard electronic instruments and often directly control autopilots.
Chase gun, chase piece, or chaser
A cannon pointing forward or aft, often of longer range than other guns. Those on the bow (bow chaser) were used to fire upon a ship ahead, while those on the rear (stern chaser) were used to ward off pursuing vessels. Unlike guns pointing to the side, chasers could be brought to bear in a chase without slowing.
1.  Wooden blocks at the side of a spar.
2.  The sides of a block or gun-carriage.
1.  An angle in the hull.
2.  A line formed where the sides of a boat meet the bottom.[1] Soft chine is when the two sides join at a shallow angle, and hard chine is when they join at a steep angle.
Hole or ring attached to the hull to guide a line via that point. An opening in a ships bulwark normally oval in shape designed to allow mooring lines to be fastened to cleats or bits mounted to the ship's deck. See also Panama chock and Dutchman's chock.
Rigging blocks that are so tight against one another that they cannot be further tightened.[1]
A timekeeper accurate enough to be used to determine longitude by means of celestial navigation.
Cigarette boat
see go-fast boat.
A fortified safe room on a vessel to take shelter in the event of pirate attack. Previously, a fortified room to protect ammunition and machinery from damage.
Civil Red Ensign
The British Naval Ensign or Flag of the British Merchant Navy, a red flag with the Union Flag in the upper left corner. Colloquially called the "red duster".
1.  A group of naval ships of the same or similar design.
2.  A standard of construction for merchant vessels, including standards for specific types or specialized capabilities of some types of merchant vessels. A ship meeting the standard is in class, one not meeting them is out of class.
Clean bill of health
A certificate issued by a port indicating that the ship carries no infectious diseases. Also called a pratique.
Clean slate
At the helm, the watch keeper would record details of speed, distances, headings, etc. on a slate. At the beginning of a new watch the slate would be wiped clean.
To perform customs and immigration legalities prior to leaving port.
A stationary device used to secure a rope aboard a vessel.[1]
A method of fixing together two pieces of wood, usually overlapping planks, by driving a nail through both planks as well as a washer-like rove. The nail is then burred or riveted over to complete the fastening.
The lower corners of square sails or the corner of a triangular sail at the end of the boom.[1]
Used to truss up the clews, the lower corners of square sails. Used to reduce and stow a barge's topsail.[1]
Clinker built
A method of constructing hulls that involves overlapping planks, and/or plates, much like Viking longships, resulting in speed and flexibility in small boat hulls. Cf. "carvel built".
A very fast sailing ship of the 19th century that had three or more masts, a square rig, a long, low hull, and a sharply raked stem.
Close aboard
Near a ship.
Of a vessel beating as close to the wind direction as possible.
Clove hitch
A bend used to attach a rope to a post or bollard. Also used to finish tying off the foresail.[1]
Club hauling
The ship drops one of its anchors at high speed to turn abruptly. This was sometimes used as a means to get a good firing angle on a pursuing vessel. See kedge.
Coal hulk
A hulk used to store coal.
Coal trimmer, or Trimmer
person responsible for ensuring that a coal-fired vessel remains in 'trim' (evenly balanced) as coal is consumed on a voyage.
The raised edge of a hatch, cockpit or skylight to help keep out water.
Coaster (or coastal trading vessel)
A shallow-hulled ship used for trade between locations on the same island or continent.
Used of spars, to stow by swinging askew.[1]
The seating area (not to be confused with Deck). The area towards the stern of a small decked vessel that houses the rudder controls.
A type of sailing ship with a single mast and square-rigged single sail first developed in the 10th century and widely used, particularly in the Baltic Sea region, in seagoing trade from the 12th through the 14th century.
A bulk cargo ship designed to carry coal, especially such a ship in naval use to supply coal to coal-fired warships.
Combat loading
A way of loading a vessel giving military forces embarked aboard her immediate access to weapons, ammunition and supplies they need when conducting an amphibious landing. In combat loading, cargo is stowed in such a way that unloading of equipment will match up with the personnel that are landing and in the order they land so that they have immeidate access to the gear they need for combat as soon as they land. Combat loading gives primary consideration to the ease and sequence with which troops, equipment, and supplies can be unloaded ready for combat, sacrificing the more efficient use of cargo space that ship operators seek when loading a ship for the routine transportation of personnel and cargo.
A long, curving wave breaking on the shore.
Come about
1.  To tack.
2.  To change tack.
3.  To manoeuvre the bow of a sailing vessel across the wind so that the wind changes from one side of the vessel to the other.
4.  To position a vessel with respect to the wind after tacking.
Come to
To stop a sailing vessel, especially by turning into the wind.
To formally place (a naval vessel) into active service, after which the vessel is said to be in commission. Sometimes used less formally to mean placing a commercial ship into service.
1.  Commodore (rank), a military rank used in many navies that is superior to a navy captain, but below a rear admiral. Often equivalent to the rank of "flotilla admiral" or sometimes "counter admiral" in non-English-speaking navies.
2.  Convoy Commodore, a civilian put in charge of the good order of the merchant ships in British convoys during World War II, but with no authority over naval ships escorting the convoy.
3.  Commodore (yacht club), an officer of a yacht club.
4.  Commodore (Sea Scouts), a position in the Boy Scouts of America's Sea Scout program.
Communication tube, speaking tube, or voice tube
An air-filled tube, usually armored, allowing speech between the conning tower with the below-decks control spaces in a warship.
A raised and windowed hatchway in the ship's deck, with a ladder leading below and the hooded entrance-hatch to the main cabins.
Navigational instrument showing the direction of the vessel in relation to the Earth's geographical poles or magnetic poles. Commonly consists of a magnet aligned with the Earth's magnetic field, but other technologies have also been developed, such as the gyrocompass.
1.  The number of persons in a ship′s crew, including officers.
2.  A collective term for all of the persons in a ship′s crew, including officers.
To include or contain: As applied to a naval task force, the listing of all assigned units for a single transient purpose (mission). "The Task Force comprises Ship A, Ship B, and Ship C." 'Comprise' means exhaustive inclusion – there aren't any other parts to the task force, and each ship has a permanent squadron existence, independent of the task force.
(Also written con, conne, conde, cunde, or cun) To direct a ship or submarine from a position of command. While performing this duty, an officer is said to have the conn.
Conning officer
An officer on a naval vessel responsible for instructing the helmsman on the course to steer. While performing this duty, the officer is said to have the conn.
Conning tower
1.  The armoured control tower of an iron or steel warship built between the mid-19th and mid-20th centuries from which the ship was navigated in battle.
2.  A tower-like structure on the dorsal (topside) surface of a submarine, serving in submarines built before the mid-20th century as a connecting structure between the bridge and pressure hull and housing instruments and controls from which the periscopes were used to direct the submarine and launch torpedo attacks. Since the mid-20th century, it has been replaced by the sail (United States usage) or fin (European and British Commonwealth usage), a structure similar in appearance which no longer plays a function in directing the submarine.
Unpowered Great Lakes vessels, usually a fully loaded schooner, barge, or steamer barge, towed by a larger steamer that would often tow more than one barge. The consort system was used in the Great Lakes from the 1860s to around 1920.
Constant bearing, decreasing range (CBDR)
When two boats are approaching each other from any angle and this angle remains the same over time (constant bearing) they are on a collision course. Because of the implication of disaster (ships might collide) it has come to mean a problem or an obstacle which is heading your way. Often used in the sense of a warning, as in "watch out for this problem you might not see coming."[14]
Container ship
A cargo ship that carries all of her cargo in truck-size intermodal containers.
A group of ships traveling together for mutual support and protection.
An amateur yachter.[15][16]
A device to correct the ship's compass, for example counteracting errors due to the magnetic effects of a steel hull.
1.  A French privateer, especially from the port of St-Malo.
2.  Any privateer or pirate.
3.  A ship used by privateers or pirates, especially of French nationality.
4.  Corsair, a class of 16-foot (4.9-meter) three-handed sailing dinghy.
1.  A flush-decked sailing warship of the 17th, 18th, and 19th centuries having a single tier of guns, ranked next below a frigate. Called in the US Navy a sloop-of-war.
2.  A lightly armed and armored warship of the 20th and 21st centuries, smaller than a frigate, capable of trans-oceanic duty.
A part load.[17]
A steam-powered wooden warship protected from enemy fire by bales of cotton lining its sides, most commonly associated with some of the warships employed by the Confederate States of America during the American Civil War (1861–1865).
The part of the stern above the waterline that extends beyond the rudder stock culminating in a small transom. A long counter increases the waterline length when the boat is heeled, so increasing hull speed.
To deliberately flood compartments on the opposite side from already flooded ones. Usually done to reduce a list.
The direction in which a vessel is being steered, usually given in degrees.
the lowest square sail on each mast – The mainsail, foresail, and the mizzen on a four masted ship (the after most mast usually sets a gaff driver or spanker instead of a square sail).
1.  A ship's ventilator with a bell-shaped top which can be swivelled to catch the wind and force it below.
2.  A vertical projection of a ship's funnel which directs the smoke away from the bridge.
Coxswain or cockswain /ˈkɒksən/
The helmsman or crew member in command of a boat.
A winch used for raising the leeboard which has a barrel fir pulling in the staysail sheets.[1]
Crance/Crans/Cranze iron
A fitting, mounted at the end of a bowsprit to which stays are attached.
Crane vessel or crane ship
A ship with a crane specialized in lifting heavy loads.
Crazy Ivan
US Navy slang for a maneuver in which a submerged Soviet or Russian submarine suddenly turns 180 degrees or through 360 degrees to detect submarines following it.
1.  On warships and merchant ships, those members of a ship's company who are not officers
2.  On leisure vessels with no formal chain of command, those persons who are not the skipper (q.v.) or passengers.
Crew management
Otherwise known as crewing, are the services rendered by specialised shipping companies to manage the human resources and manning of all types of vessels, including recruitment, deployment to vessel, scheduling, training, as well as the ongoing management and administrative duties of seafarers, such as payroll, travel arrangements, insurance and health schemes, overall career development, as well as their day-to-day welfare
A rope loop, usually at the corners of a sail, for fixing the sail to a spar. They are often reinforced with a metal eye.[1]
Cro'jack or crossjack
a square yard used to spread the foot of a topsail where no course is set, e.g. on the foremast of a topsail schooner or above the driver on the mizzen mast of a ship rigged vessel.
two horizontal struts at the upper ends of the topmasts of sailboats, used to anchor the shrouds from the topgallant mast. Lateral spraders for the topmast shrouds (standing back stays) [1]
Crow flies, as the
see as the crow flies.
Crow's nest
Specifically a masthead constructed with sides and sometimes a roof to shelter the lookouts from the weather, generally by whaling vessels, this has become a generic term for what is properly called masthead. See masthead.
Cruise ship
A passenger ship used for pleasure voyages, where the voyage itself and the ship's amenities are part of the experience, as well as the different destinations along the way. Transportation is not the prime purpose, as cruise ships operate mostly on routes that return passengers to their originating port. A cruise ship contrasts with a passenger liner, which is a passenger ship that provides a scheduled service between published ports primarily as a mode of transportation. Large, prestigious passenger ships used for either purpose sometimes are called ocean liners.
1.  From the mid-19th century to the mid-20th century, a classification for a wide variety of gun- and sometimes torpedo-armed warships, usually but not always armored, intended for independent scouting, raiding, or commerce protection; some were designed also to provide direct support to a battlefleet. Cruisers carried out functions performed previously by the cruising ships (sailing frigates and sloops) of the Age of Sail.
2.  From the early 20th century to the mid-20th century, a type of armored warship with varying armament and of various sizes, but always smaller than a battleship and larger than a destroyer, capable of both direct support of a battle fleet and independent operations, armed with guns and sometimes torpedoes.
3.  After the mid-20th century, various types of warships of intermediate size armed with guided missiles and sometimes guns, intended for air defense of aircraft carriers and associated task forces or for anti-ship missile attack against such forces; virtually indistinguishable from large destroyers since the late 20th century.
Metal Y shaped pins to hold oars whilst rowing.
A small cabin in a boat; a cabin, for the use of the captain, in the after part of a sailing ship under the poop deck.
A line invented by Briggs Cunningham, used to control the shape of a sail.
Cunt splice or cut splice
A join between two lines, similar to an eye-splice, where each rope end is joined to the other a short distance along, making an opening which closes under tension.
The "valley" between the strands of a rope or cable. Before serving a section of laid rope e.g. to protect it from chafing, it may be "wormed" by laying yarns in the cuntlines, giving that section an even cylindrical shape.
Cut and run
When wanting to make a quick escape, a ship might cut lashings to sails or cables for anchors, causing damage to the rigging, or losing an anchor, but shortening the time needed to make ready by bypassing the proper procedures.
Cut of his jib
The "cut" of a sail refers to its shape. Since this would vary between ships, it could be used both to identify a familiar vessel at a distance, and to judge the possible sailing qualities of an unknown one, during the 16th and 17th centuries, the ships of different nations used visually distinctive types of jibs that could be determined at a distance, providing an easy way to determine friend from foe.[18] Also used figuratively of people.[19]
1.  A small single-masted boat, fore-and-aft rigged, with two or more headsails and often a bowsprit. The mast is set farther back than on a sloop.
2.  A small boat serving a larger vessel, used to ferry passengers or light stores between larger vessels and the shore.
3.  In the 20th and 21st centuries, a small- or medium-sized vessel whose occupants exercise official authority, such as harbor pilots' cutters, US Coast Guard Cutters, and UK Border Agency cutters.
The forward curve of the stem (q.v.) of a ship


A type of light centerboard that is lifted vertically; often in pairs, with the leeward one lowered when beating.
1.  A rig with a small mizzen abaft the steering post.[1]
2.  In British usage, an alternative term for a yawl (q.v.).
3.  In British usage, a small after-sail on a yawl.
To run dart, to run dead before the wind.[1]
1.  A spar formerly used on board ships as a crane to hoist the flukes of the anchor to the top of the bow, without injuring the sides of the ship.
2.  A crane, often working in pairs and usually made of steel, used to lower things over the side of a ship, including launching a lifeboat over the side of a ship.
Davy Jones' Locker
An idiom for the bottom of the sea.
Day beacon
An unlighted fixed structure which is equipped with a dayboard for daytime identification.
Moment at dawn where, from some point on the mast, a lookout can see above low lying mist which envelops the ship.
The daytime identifier of an aid to navigation presenting one of several standard shapes (square, triangle, rectangle) and colors (red, green, white, orange, yellow, or black).
Dead ahead
Exactly ahead, directly ahead, directly in front.
Dead in the water
Not moving (used only when a vessel is afloat and neither tied up nor anchored). Term is abbreviated to DIW by the US Navy, it is often used to indicate a pirate or drug runner vessel has been immobilised.
Dead run
See running.
Dead wake
The trail of a fading disturbance in the water. See also wake.
A wooden block with three holes (but no pulleys) which is spliced to a shroud. It is used to adjust the tension in the standing rigging of large sailing vessels, by lacing through the holes with a lanyard to the deck. Performs the same job as a turnbuckle.[1]
A snag (q.v.).
A strong shutter fitted over a porthole or other opening that can be closed in bad weather.
The design angle of the hull at the keel (q.v.) relative to horizontal when viewing the cross section, or the distance of rise from the keel to a defined point on the hull.
A wooden part (vertical timbers or planking) of the centerline structure of a boat, usually between the sternpost and amidships. It is used to "fill the spaces where, owing to the shape of the vessel, the floor-timbers have to be discontinued."[20][21]
Death roll
In a keel boat, a death roll is the act of broaching to windward, putting the spinnaker pole into the water and causing a crash-gybe of the boom and mainsail, which sweep across the deck and plunge down into the water. During a death roll, the boat rolls from side to side, becoming gradually more unstable until either it capsizes or the skipper reacts correctly to prevent it.
Debarcation or disembarkation
The process of leaving a ship or aircraft, or removing goods from a ship or aircraft.
The process of removing fuel from a vessel. After a ship wreck, a "debunkering" operation will be performed in an effort to minimize damage and protect the environment from fuel spills.
The top of the boat; the surface is removed to accommodate the seating area. The structures forming the approximately horizontal surfaces in the ship's general structure. Unlike flats, they are a structural part of the ship.
Deck hand or decky
A person whose job involves aiding the deck supervisor in (un)mooring, anchoring, maintenance, and general evolutions on deck.
Deck supervisor
The person in charge of all evolutions and maintenance on deck; sometimes split into two groups: forward deck supervisor, aft deck supervisor.
The under-side of the deck above. The inside of the boat is normally paneled over to hide the structure, pipes, electrical wires, it can be in thin wood planks, often covered with a vinyl lining, or in thin PVC or now even in fiberglass planks.
A cabin (q.v.) which protrudes above a ship's deck.
Decks awash
A situation in which the deck of the vessel is partially or wholly submerged, possibly as a result of excessive listing or a loss of buoyancy.
To formally take (a naval vessel) out of active service, after which the vessel is said to be out of commission or decommissioned. Sometimes used less formally to mean taking a commercial ship out of service.
Ded. Reckoning
A method of navigation by determining the ship's position using only its previously known position and deriving its new position from the course, speed, and elapsed time provided by instruments or estimation. Ded. Reckoning is used when no other forms of more precise navigation are available (for example, because a ship is fogged in) because all errors are additive and must be corrected for when better navigation information is available, such as the sighting of a landmark or a celestial navigation position fix. Abbreviation for "Deduced reckoning" and often mistakenly referred to as "dead reckoning"
Depot ship
A ship which acts as a mobile or fixed base for other ships and submarines or supports a naval base.
Depth of hold
The height from the lowest part of the hull inside the ship, at its midpoint, to the ceiling that is made up of the uppermost full length deck. For old warships it is to the ceiling that is made up of the lowermost full length deck.
A lifting device composed of one mast or pole and a boom or jib which is hinged freely at the bottom.
Despatch boat
Alternative spelling of dispatch boat.
Destroyer (originally torpedo boat destroyer)
A type of fast and maneuverable small warship introduced in the 1890s to protect capital ships from torpedo boat attack, since increased in size and capabilities to become a long-endurance warship intended to escort larger vessels in a fleet, convoy, or battle group and defend them against submarines, surface ships, aircraft, and missiles.
Destroyer depot ship
See destroyer tender.
Destroyer escort
US Navy term for a smaller, lightly armed warship built in large numbers during World War II (and in smaller numbers thereafter), cheaper, slower, and less-well-armed than a destroyer but larger and more heavily armed than a corvette and designed to escort convoys of merchant ships or naval auxiliaries or second-line naval forces. Employed primarily for anti-submarine warfare, but also provided some protection against aircraft and smaller surface ships. Generally known as "frigates" in other navies, and designated as such in the US Navy as well by the 1970s.
Destroyer leader
A large destroyer suitable for commanding a flotilla of destroyers or other small warships; a type of flotilla leader.
Destroyer tender
A naval auxiliary ship designed to provide maintenance support to a flotilla of destroyers or other small warships. Known in British English as a destroyer depot ship.
Devil seam
The devil was possibly a slang term for the garboard seam, hence "between the devil and the deep blue sea" being an allusion to keel hauling, but a more popular version seems to be the seam between the waterway and the stanchions which would be difficult to get at, requiring a cranked caulking iron, and a restricted swing of the caulking mallet.
Devil to pay (or Devil to pay, and no pitch hot)
"Paying" the devil is sealing the devil seam. It is a difficult and unpleasant job (with no resources) because of the shape of the seam (up against the stanchions) or if the devil refers to the garboard seam, it must be done with the ship slipped or careened.
the generic name of a number of traditional sailing vessels with one or more masts with lateen sails used in the Red Sea and Indian Ocean region, typically weighing 300 to 500 tons, with a long, thin hull. They are trading vessels primarily used to carry heavy items, like fruit, fresh water or merchandise. Crews vary from about thirty to around twelve, depending on the size of the vessel.
1.  A type of small boat, often carried or towed as a ship's boat by a larger vessel.
2.  Also a small racing yacht or recreational open sailing boat, often used for beginner training rather than sailing full-sized yachts.
Directional light
A light illuminating a sector or very narrow angle and intended to mark a direction to be followed.
Dipping the eye
Dipping the eye
Method of attaching more than one hawser to a single bollard, so that each can be lifted off without disturbing the other(s). The second hawser is passed under the first, then up through the eye of the first (hence the name), before being secured over the bollard.

Dispatch boat
A vessel ranging in size from a small boat to a large ship tasked to carry military dispatches from ship to ship, from ship to shore, or, occasionally, from shore to shore.
The weight of water displaced by the immersed volume of a ship's hull, exactly equivalent to the weight of the whole ship.
Displacement hull
A hull designed to travel through the water, rather than planing over it.
To reduce in rank or rating; demote.
Distinguishing mark
A flag flown to distinguish ships of one seagoing service of a given country from ships of the country's other seagoing service(s) when ships of more than one of the country's seagoing services fly the same ensign.
1.  In American usage, a fixed structure attached to shore to which a vessel is secured when in port, generally synonymous with pier and wharf, except that pier tends to refer to structures used for tying up commercial ships and to structures extending from shore for use in fishing, while dock refers more generally to facilities used for tying up ships or boats, including recreational craft.
2.  In British usage, the body of water between two piers or wharves which accommodates vessels tied up at the piers or wharves.
3.  To tie up along a pier or wharf.
A facility where ships or boats are built and repaired. Routinely used as a synonym for shipyard, although dockyard sometimes is associated more closely with a facility used for maintenance and basing activities, while shipyard sometimes is associated more closely with a facility used in construction.
A hood forward of a hatch or cockpit to protect the crew from wind and spray. Can be soft or hard.
Dog watch
A short watch period, generally half the usual time (e.g. a two-hour watch rather than a four-hour one). Such watches might be included in order to rotate the system over different days for fairness, or to allow both watches to eat their meals at approximately normal times.
A slang term (in the US, mostly) for a raised portion of a ship's deck. A doghouse is usually added to improve headroom below or to shelter a hatch.
A small weather vane, sometimes improvised with a scrap of cloth, yarn or other light material mounted within sight of the helmsman. (See tell-tale)
Doldrums or equatorial calms
The equatorial trough, with special reference to the light and variable nature of the winds.[22]
Dolly winch
A small winch mounted on the windlass which is used as an alternative to the brails winch when that is obstructed in some way. (stack, deck cargo, for example)[1]
A structure consisting of a number of piles driven into the seabed or riverbed as a marker.
Donkey engine
A small auxiliary engine used either to start a larger engine or independently, e.g. for pumping water on steamships.[23]
One of a ship's engineering crew. Often a crewman responsible for maintaining a Steam donkey, or any machinery other than the main engines, on some ships, the Petty Officer in charge of engineroom ratings.
Dory or doree, dori, or (Royal Navy) dorey
A shallow-draft, lightweight boat, about 5 to 7 metres (16 to 23 feet) long, with high sides, a flat bottom and sharp bows. Traditionally used as fishing boats, both in coastal waters and in the open sea.
The practice of loading smooth-bore cannon with two cannon-balls.
Dover cliffs
Very rough seas with large white capped waves.
1.  A vessel traveling downstream.
2.  Eastward-traveling vessels in the Great Lakes region (terminology as used by the St. Lawrence Seaway Development Corporation).
A line used to control either a mobile spar, or the shape of a sail. A downhaul can also be used to retrieve a sail back on deck.
An extra strip of canvas secured below a bonnet (q.v.), further to increase the area of a course
Draft or draught (both /drɑːft/)
The depth of a ship's keel below the waterline.
Dragon boat (also dragonboat)
One of a family of traditional paddled long boats of various designs and sizes found throughout Asia, Africa and the Pacific Islands. For competitive events, they are generally rigged with decorative Chinese dragon heads and tails. Dragon boat races are traditionally held during the annual summer solstice festival.
A type of battleship designed with an "all-big-gun" armament layout in which the ship's primary gun power resided in a primary battery of its largest guns intended for use at long range, with other gun armament limited to small weapons intended for close-range defense against torpedo boats and other small warships. Most, but not all, dreadnoughts also had steam turbine propulsion. Predominant from 1906, dreadnoughts differed from earlier steam battleships, retroactively dubbed "predreadnoughts", which had only a few large guns, relied on an intermediate secondary battery used at shorter ranges for most of their offensive power, and had triple-expansion steam engines.
Dress overall
To string International Code of Signals flags, arranged at random, from stemhead to masthead, between mastheads (if the vessel has more than one mast), and then down to the taffrail, on a ship in harbor as a sign of celebration of a national, local, or personal anniversary, event, holiday, or occasion. When a ship is properly dressed overall, ensigns fly at each masthead unless displaced by another flag – for example, that of a flag officer on board – in addition to the ensign flown in the usual position at the stern.
Dressing down
1.  Treating old sails with oil or wax to renew them.
2.  A verbal reprimand.
Dressing lines
Lines running from stemhead to masthead, between mastheads, and then down to the taffrail, to which flags are attached when a ship is dressed overall.
A type of fishing boat designed to catch herring in a long drift net, long used in the Netherlands and Great Britain.
Overboard and into the water, as it fell into the drink.
The large sail flown from the mizzen gaff.
The fifth mast of a six-masted barquentine or gaff schooner. It is preceded by the jigger mast and followed by the spanker mast, the sixth mast of the only seven-masted vessel, the gaff schooner Thomas W. Lawson, was normally called the pusher-mast.
Drogue /drɡ/
A device to slow a boat down in a storm so that it does not speed excessively down the slope of a wave and crash into the next one. It is generally constructed of heavy flexible material in the shape of a cone. See also sea anchor.
A technique of maintaining steerage-way when going downstream with neither engine nor wind to sail. The vessel uses its anchor to draw itself head-to-stream, then lifts the anchor and drifts stern-first downstream, ferry gliding to maintain position within the stream. As steerage begins to reduce, the vessel anchors again and then repeats the whole procedure as required.
A narrow basin or vessel used for the construction, maintenance, and repair of ships, boats, and other watercraft that can be flooded to allow a load to be floated in, then drained to allow that load to come to rest on a dry platform.
Dunnage /ˈdʌnɪ/
1.  Loose packing material used to protect a ship's cargo from damage during transport. (See also fardage)
2.  Personal baggage.
A part on a ship that has no use.


Small lines, by which the uppermost corners of the largest sails are secured to the yardarms.
East Indiaman
Any ship operating under charter or license to the East India Company (England), or to the Danish East India Company, French East India Company, Dutch East India Company, Portuguese East India Company, or Swedish East India Company from the 17th to the 19th centuries.
Echo sounding
Measuring the depth of the water using a sonar device. See also sounding and swinging the lead.
The condition where a sailing vessel (especially one which sails poorly to windward) is confined between two capes or headlands by a wind blowing directly onshore.
En echelon
An arrangement of gun turrets whereby the turret on one side of the ship is placed further aft than the one on the other side, so that both turrets can fire to either side.
Diagram showing the Minas Geraes-class battleship with its central guns arranged en echelon.

Engine order telegraph
A communications device used by the pilot to order engineers in the engine room to power the vessel at a certain desired speed. Also Chadburn.
Engine room
One of the machinery spaces of a vessel, usually the largest one, containing the ship's prime mover (usually a diesel or steam engine or a gas or steam turbine). Larger vessels may have more than one engine room.
1.  Ensign, the principal flag or banner flown by a ship to indicate her nationality.
2.  Ensign, the lowest grade of commissioned officer in the US Navy.
Escort carrier
An aircraft carrier, smaller and slower than a fleet carrier, used by some navies in World War II to escort convoys, ferry aircraft, and provide air support for amphibious operations.
(also known as "in extremis") the point under International Rules of the Road (Navigation Rules) at which the privileged (or stand-on) vessel on collision course with a burdened (or give-way) vessel determines it must maneuver to avoid a collision. Prior to extremis, the privileged vessel must maintain course and speed and the burdened vessel must maneuver to avoid collision.
Eye splice
A closed loop or eye at the end a line, rope, cable, etc. It is made by unraveling its end and joining it to itself by intertwining it into the lay of the line. Eye splices are very strong and compact and are employed in moorings and docking lines among other uses.


Factory ship
A large ocean-going vessel with extensive on-board facilities for processing and freezing caught fish or whales. Some also serve as mother ships (q.v.) for smaller fishing or whaling vessels. Those used for processing fish are also known as fish processing vessels.
1.  A smooth curve, usually referring to a line of the hull which has no deviations.
2.  To make something flush.
3.  A line is fair when it has a clear run.
4.  A wind or current is fair when it offers an advantage to a boat.
Fair winds and following seas
A blessing wishing the recipient a safe journey and good fortune.
A ring, hook or other device used to keep a line or chain running in the correct direction or to prevent it rubbing or fouling.[1]
A structure that improves the streamlining of a vessel.
1.  Generally, a navigable channel, for example in a harbor or offshore, that is the usual course taken by vessels in the area.
2.  In military and naval terms, a channel from offshore, in a river, or in a harbor that has enough depth to accommodate the draft of large vessels.
To coil a rope down on the deak to enable it to pay out without fouling.[1]
A traditional fishing boat with a lateen sail on a single mast used by fishermen from the town of Komiža on the Adriatic island of Vis.
The part of the tackle that is hauled upon.[1]
Fall off
To change the direction of sail so as to point in a direction that is more down wind. To bring the bow leeward. Also bear away, bear off or head down, this is the opposite of pointing up or heading up.
Aft end of the ship, also known as the Poop deck.
Wood placed in bottom of ship to keep cargo dry. (See also dunnage)
Fashion boards
Loose boards that slide in grooves to close off a companionway or cabin entrance.[1]
Fastened or held firmly (fast aground: stuck on the seabed; made fast: tied securely).[1]
Fathom /ˈfæðəm/
A unit of length equal to 6 feet (1.8 m), roughly measured as the distance between a man's outstretched hands. Particularly used to measure depth.
A depth finder that uses sound waves to determine the depth of water.
A traditional wooden sailing boat with a rig consisting of one or two lateen sails, used in protected waters of the Red Sea and eastern Mediterranean and particularly along the Nile in Egypt and Sudan, and also in Iraq.
Fend off
A command given to the crew to stop what they are now doing and to immediately manually prevent the boat from banging into the docks or other boats.
A flexible bumper used in boating to keep boats from banging into docks or each other. Often an old car tyre.[1]
Ferry glide
1.  To hold a vessel against and at an angle to the current/stream such that the vessel moves sideways over the bottom due to the effect of the current operating on the upstream side of the vessel.
1.  The distance across water which a wind or waves have traveled.
2.  To reach a mark without tacking.
1.  A tapered wooden tool used for separating the strands of rope for splicing.
2.  A bar used to fix an upper mast in place.
Fife rail
A freestanding pinrail surrounding the base of a mast and used for securing that mast's sails' halyards with a series of belaying pins.
A sailing boat with two masts with a standard rig consisting of a main dipping lug sail and a mizzen standing lug sail developed in Scotland; used for commercial fishing from the 1850s until the 20th century.
US Navy slang for a guided-missile frigate, especially of the Oliver Hazard Perry class, derived from its class designation ("FFG").
Fighting top
An enlarged top designed to allow gunfire downward onto an enemy ship. A fighting top could have small guns installed in it or could serve as a platform for snipers armed with muskets or rifles.
Figure of eight
A stopper knot.[1]
A symbolic image at the head of a traditional sailing ship or early steamer.
A term used in European and British Commonwealth countries for a tower-like structure on the dorsal (topside) surface of a submarine; called a sail in the United States.
Narrow (fine) in appearance from the vantage point of a lookout or other person viewing activity in the vicinity of a ship, e.g., another ship off the starboard bow with her bow or stern facing the viewer's ship could be described as "fine on the starboard bow" of the viewer's ship.
A specialized vessel equipped with firefighting equipment such as pumps and nozzles for fighting shipboard and shoreline fires.
Fire ship
A ship loaded with flammable materials and explosives and sailed into an enemy port or fleet either already burning or ready to be set alight by its crew (who would then abandon it) in order to collide with and set fire to enemy ships.
Fire room, also boiler room
The compartment in which the ship's boilers or furnaces are stoked and fired.
The classification for the largest sailing warships of the 17th through 19th centuries. They had 3 masts, 850+ crew and 100+ guns.
First lieutenant
1.  In the Royal Navy, the senior lieutenant on board; responsible to the commanding officer for the domestic affairs of the ship's company. Also known as 'Jimmy the One' or 'Number One'. Removes his cap when visiting the mess decks as token of respect for the privacy of the crew in those quarters. Officer in charge of cables on the forecastle.
2.  In the US Navy, the officer on a ship serving as the senior person in charge of all deck hands.
First mate
The second-in-command of a commercial ship.
1.  To repair a mast or spar with a fillet of wood.
2.  To secure an anchor on the side of the ship for sea (otherwise known as "catting".)
3.  A slang term for a self-propelled torpedo.
Fisherman's reef
A sailing tactic for handling winds too strong for the sail area hoisted when reefing the sails is not feasible or possible. The headsail is set normally while the mainsail is let out till it is constantly luffing, this creates loss of force on the main and also reduces the efficiency of the headsail while still retaining sailing control of the vessel.
The period after a ship is launched during which all the remaining construction of the ship is completed and she is readied for sea trials and delivery to her owners.
Fixed propeller
A propeller mounted on a rigid shaft protruding from the hull of a vessel, usually driven by an inboard motor; steering must be done using a rudder. See also outboard motor and sterndrive.
Flag hoist
A number of signal flags strung together to convey a message, e.g., 'England expects...'
Flag of convenience
The business practice of registering a merchant ship in a sovereign state different from that of the ship's owners, and flying that state's civil ensign on the ship. The practice allows the ship's owner to reduce operating costs or avoid the regulations of the owner's country.
Flag officer
1.  A commissioned officer senior enough to be entitled to fly a flag to mark the ship or installation from which he or she exercises command, in English-speaking countries usually referring to the senior officers of a navy, specifically those who hold any of the admiral ranks and in some cases to those holding the rank of commodore. In modern American usage, additionally applied to US Coast Guard and National Oceanic and Atmospheric Administration Commissioned Corps officers and general officers in the US Army, US Air Force, and US Marine Corps entitled to fly their own flags.
2.  A formal rank in the mid-19th-century US Navy, conveyed temporarily upon senior captains in command of squadrons of ships, soon rendered obsolete by the creation of the ranks of commodore and rear admiral.
1.  A vessel used by the commanding officer of a group of naval ships. The term derives from the custom of the commander of such a group of ships, characteristically a flag officer, flying a distinguishing flag aboard the ship on which he or she is embarked.
2.  Used more loosely, the lead ship in a fleet of naval or commercial vessels, typically the first, largest, fastest, most heavily armed, or, in terms of media coverage, best-known.
The maximum speed of a ship. Faster than "full speed".
1.  A curvature of the topsides outward towards the gunwale.
2.  A pyrotechnic signalling device, usually used to indicate distress.
A Great Lakes slang term for a vessel without any self-unloading equipment.
Slang term for an aircraft carrier (q.v.).
To coil a line that is not in use so that it lies flat on the deck.
Flettner rotor
A spinning cylinder that uses the Magnus effect to harness wind power to propel a ship.
Flight deck
A flat deck used for the launch and recovery of aircraft.
The transverse structural timbers to which the longitudinal bottom planking is attached. The equivalent side timbers are called the frames, the keelson is fastened on top of the floors, bolting them to the keel. The planking is the exterior of the hull, while the ceiling is attached on top of the floors, and it forms the base of the hold. [1]
Any of the upper extremities of the floor (q.v.) of a vessel.
Flotilla leader
A warship suitable for commanding a flotilla of destroyers or other small warships, typically a small cruiser or a large destroyer, in the latter case known as a destroyer leader.
Debris or cargo that remains afloat after a shipwreck. See also jetsam.
The wedge-shaped part of an anchor's arms that digs into the bottom.
Flush deck
An upper deck of a vessel that extends unbroken from stem to stern.
Flush decker
1.  A US Navy destroyer of the World War I-era Caldwell, Wickes, or Clemson class, produced in very large numbers.
2.  Any ship with a flush deck.
Flushing board
Board inserted vertically in a cabin entrance.[1]
Fluyt (also fluit or flute)
A Dutch transoceanic sailing cargo vessel, square-rigged with two or three masts that were much taller than the masts of a galleon, developed in the 16th century and widely used in the 17th and 18th centuries.
Fly by night
A large sail used only for sailing downwind, requiring little attention.
Folding propeller
A propeller with folding blades, furling to reduce drag on a sailing vessel when not in use.
Following sea
Wave or tidal movement going in the same direction as a ship
Foo-foo band
An impromptu musical band on late 19th-century sailing vessels, made up from members of the ship's crew[24][25]
1.  The lower edge of any sail.[1]
2.  The bottom of a mast.
3.  A measurement of 12 inches.
If the foot of a sail is not secured properly, it is footloose, blowing around in the wind.
A barges boat or dinghy.[1]
Each yard on a square rigged sailing ship is equipped with a footrope for sailors to stand on while setting or stowing the sails
See Beaufort scale.
Fore, forward (/ˈfɒrərd/, and often written "for'ard")
Towards the bow (of the vessel).
Fore-and-aft rig
A sailing rig consisting mainly of sails that are set along the line of the keel rather than perpendicular to it. Such sails are referred to as "fore-and-aft rigged."
removable wooded beams running along the centre of the hold openings, beneath the hatches that they support[1]
Fore horse
Transverse wooden or iron beam afore the main mast to which the foresail sheet is attached.[1]
A partial deck, above the upper deck and at the head of the vessel; traditionally the sailors' living quarters. Pronounced /ˈfksəl/. The name is derived from the castle fitted to bear archers in time of war.[1]
The lower part of the stem of a ship.
Foremast jack
An enlisted sailor, one who is housed before the foremast.
The part of the hold of a ship within the angle of the bow.
1.  A fore and aft sail set on the foremast.
2.  The lowest sail set on the foremast of a full rigged ship or other vessel which is square-rigged.
Long lines or cables, reaching from the bow of the vessel to the mast heads, used to support the mast.[1]
Triangular sail set on the forestay.[1] → Forestaysail (Wiktionary)
1.  Having freedom of motion interfered with by collision or entanglement; entangled; the opposite of clear. For instance, a rope is foul when it does not run straight or smoothly, and an anchor is foul when it is caught on an obstruction.
2.  A breach of racing rules.
3.  An area of water treacherous to navigation due to many shallow obstructions such as reefs, sandbars, or many rocks, etc.
4.  Foul the range: To block another vessel from firing her guns at a target.
Slang for oilskins, the foul-weather clothing worn by sailors. See also oilskins.
To fill with water and sink → Founder (Wiktionary)
Four piper
A term sometimes used to refer to United States Navy four-funneled destroyers of the Bainbridge, Paulding, Wickes, and Clemson classes, all built for service in World War I.
Fourth rate
In the British Royal Navy, a fourth rate was, during the first half of the 18th century, a ship of the line mounting from 46 up to 60 guns.
A transverse structural member which gives the hull strength and shape. Wooden frames may be sawn, bent or laminated into shape. Planking is then fastened to the frames. A bent frame is called a timber.
The height of a ship's hull (excluding superstructure) above the waterline. The vertical distance from the current waterline to the lowest point on the highest continuous watertight deck, this usually varies from one part to another.
A cargo ship.
1.  In the 17th century, any warship built for speed and maneuverability.
2.  In the 18th and early 19th centuries, a sailing warship with a single continuous gun deck, typically used for patrolling, blockading, etc., but not in line of battle.
3.  In the second half of the 19th century, a type of warship combining sail and steam propulsion, typically of ironclad timber construction, with all guns on one deck.
4.  In the 20th and 21st centuries, a warship, smaller than a destroyer, originally introduced during World War II as an anti-submarine vessel but now general-purpose.
5.  In the US Navy from the 1950s until the 1970s, a type of guided-missile antiaircraft ship built on a destroyer-sized hull, all reclassified as "guided-missile cruisers" in 1975.
Full and by
Sailing into the wind (by), but not as close-hauled as might be possible, so as to make sure the sails are kept full. This provides a margin for error to avoid being taken aback (a serious risk for square-rigged vessels) in a tricky sea. Figuratively it implies getting on with the job but in a steady, relaxed way, without undue urgency or strain.
Full-rigged ship
A sailing vessel with three or more masts, all of them square-rigged. A full-rigged ship is said to have a "ship rig".
Funnel (also stack)
The smokestack of a ship, used to expel boiler steam and smoke or engine exhaust.
To roll or gather a sail against its mast or spar.
Fusta (also fuste, foist, or galliot)
A narrow, light, and fast ship with shallow draft, powered by both oars and sail, with a single mast carrying a lateen sail; a favorite of North African corsairs during the 16th and 17th centuries.
Pieces of timber that make up a large transverse frame.


1.  Gaff rig: The spar that holds the upper edge of a four-sided fore-and-aft mounted sail.
2.  Fishing gaff: A hook on a long pole to haul fish in.
Gaff rigged
A boat rigged with a four-sided fore-and-aft sail with its upper edge supported by a spar or gaff which extends aft from the mast.
Gaff vang
A line rigged to the end of a gaff and used to adjust a gaff sail's trim.
1.  An oared warship of the 1500s equipped with a gundeck, larger and equipped with more sails than a galley.
2.  A flat-bottom commercial sailing vessel of the North Sea and western Baltic Sea.
A large, multi-decked sailing ship used primarily by European states from the 16th to 18th centuries.
1.  Galley, the kitchen of a ship.
2.  Galley, a type of ship propelled by oars used especially in the Mediterranean for warfare, piracy, and trade from the 700s BC to the 1500s AD, with some in use until the early 1800s.
3.  A type of oared gunboat built by the United States in the late 18th century, akin to a brigantine but termed "galley" for administrative and funding purposes.
See fusta.
A meeting of two (or more) whaling ships at sea. The ships each send out a boat to the other, and the two captains meet on one ship, while the two chief mates meet on the other.[26]
Gammon iron
The bow fitting which clamps the bowsprit to the stem.
A movable bridge used in boarding or leaving a ship at a pier; also known as a "brow".
An opening in the bulwark of the ship to allow passengers to board or leave the ship.
The (illegal) practice of mixing cargo with garbage.
The strake closest to the keel (from Dutch gaarboard).
Garboard planks
The planks immediately either side of the keel.
Any refuse or rubbish which is discarded into a refuse container or dustbin which is known as "gash fanny" (South African Navy).
A rope used to secure a sail (particularly the topsail) when stowed.[1]
A vessels sails and rigging.[1]
General Quarters
See Battle Stations.
A large, lightweight sail used for sailing a fore-and-aft rig down or across the wind, intermediate between a genoa and a spinnaker.
Genoa or genny (both /ˈɛni/)
A large jib, strongly overlapping the mainmast.
To sail slowly when there is apparently no wind.
See gybe.
Gig (Captain's gig)
A boat on naval ships at the disposal of the ship's captain for his or her use in transportation to other ships or to the shore.
A pole that is attached perpendicular to the mast, to be used as a lever for raising the mast. Also jin-pole.
Give-way (vessel)
Where two vessels are approaching one another so as to involve a risk of collision, this is the vessel which is directed to keep out of the way of the other.
A marine barometer. (Older barometers used mercury-filled glass tubes to measure and indicate barometric pressure.)
Global Positioning System
(GPS) A satellite based radionavigation system providing continuous worldwide coverage. It provides navigation, position, and timing information to air, marine, and land users.
Go-fast boat
is a small, fast boat designed with a long narrow platform and a planing hull to enable it to reach high speeds – also called 'a rum-runner', or, more recently, 'a cigarette boat'.
Goat locker
A mess hall reserved for Chief petty officers in the US Navy
Going about or tacking
Changing from one tack to another by going through the wind (see also gybe).
A traditional, flat-bottomed Venetian rowing boat.
Fitting that attaches the boom to the mast, allowing it to move freely.
Of a fore-and-aft rigged vessel sailing directly away from the wind, with the sails set on opposite sides of the vessel – for example with the mainsail to port and the jib to starboard, to maximize the amount of canvas exposed to the wind. See also running.
Small balls of lead fired from a cannon, analogous to shotgun shot but on a larger scale. Similar to canister shot but with larger individual shot. Used to injure personnel and damage rigging more than to cause structural damage.
To clean a ship's bottom.
Graving dock
A narrow basin, usually made of earthen berms and concrete, closed by gates or by a caisson, into which a vessel may be floated and the water pumped out, leaving the vessel supported on blocks; the classic form of drydock.
A passage of two vessels moving in the opposite direction on their starboard sides, so called because the green navigation light on one of the vessels faces the green light on the other vessel.
Great circle
The line that follows the shortest distance between two points on the globe.
Temporary eye in a line (rope).
Cockney (London dialect) name for a barge.[1]
Watered-down pusser's rum consisting of half a gill with equal part of water, issued to all seamen over twenty. (CPOs and POs were issued with neat rum) From the British Admiral Vernon who, in 1740, ordered the men's ration of rum to be watered down. He was called "Old Grogram" because he often wore a grogram coat, and the watered rum came to be called 'grog'. Often used (illegally) as currency in exchange for favours in quantities prescribed as 'sippers' and 'gulpers'. Additional issues of grog were made on the command 'splice the mainbrace' for celebrations or as a reward for performing especially onerous duties, the RN discontinued the practice of issuing rum in 1970. A sailor might repay a colleague for a favour by giving him part or all of his grog ration, ranging from "sippers" (a small amount) via "gulpers" (a larger quantity) to "grounders" (the entire tot).
Drunk from having consumed a lot of grog.
The bed of the sea.
When a ship (while afloat) touches the bed of the sea, or goes "aground" (q.v.).
A small iceberg or ice floe which is barely visible above the surface of the water.
A slave ship (q.v.).
Guard boat
A boat which makes the rounds of a fleet at anchor to see that due watch is kept at night.
Guard ship
1.  A warship stationed at a port or harbour to act as a guard there.
2.  In former times in the British Royal Navy, a ship which received men impressed for naval service, often the flagship of the admiral commanding along the coast.
3.  In Soviet and Russian terminology, a guard ship (storozhevoj korabl') is a small, general purpose patrol or escort vessel.
Gun deck
1.  Up through the 19th century, a deck aboard a ship that was primarily used for the mounting of cannon to be fired in broadsides.
2.  On smaller vessels (of frigate size or smaller) up through the 19th century, the completely covered level under the upper deck, even though in such smaller ships it carried none of the ship's guns.
3.  On marine seismic survey vessels, the lowest deck on the ship, which carries the seismic source arrays, consisting of air guns arranged in clusters.
4.  In naval slang, to fabricate or falsify something; in modern usage, meaning especially to falsify documentation in order to avoid doing work or make present conditions seem acceptable without having made a real effort to improve them.
Gunner's daughter
see Kissing the gunner's daughter.
The opening in the side of the ship or in a turret through which the gun fires or protrudes.
1.  A wire that leads from one point near the end of a gaff to a point near the other end; a block travels along the wire and a halyard is attached to the block, allowing the gaff to be raised to the vertical by a single halyard, though another halyard is required at the gaff jaws to control height.
2.  Hoops or parrel beads which secure a gaff loosely to a mast in a vertical position; a halyard is bent to the gaff jaws to control height.
Gunter rig
A vessel with a gunter-rigged mainsail.
A sail raised by means of a gunter.
Gunwale /ˈɡʌnəl/
Upper edge of the hull. The top timber on the rail round the outer edge of the deck.[1]
Gybe or jibe (both /b/)
To change from one tack to the other away from the wind, with the stern of the vessel turning through the wind. (See also going about and wearing ship.)[1]


Half-breadth plan
In shipbuilding, an elevation of the lines of a ship, viewed from above and divided lengthwise.
Halyard or halliard
Originally, ropes used for hoisting a spar with a sail attached; today, a line used to raise the head of any sail.[1]
Canvas sheets, slung from the deckhead in messdecks, in which seamen slept. "Lash up and stow" a piped command to tie up hammocks and stow them (typically) in racks inboard of the ship's side to protect crew from splinters from shot and provide a ready means of preventing flooding caused by damage.
Articles that normally are indispensable aboard ship, but at certain times are in the way.
To furl a sail.
Hand bomber
A ship using coal-fired boilers shoveled in by hand.
Hand over fist
To climb steadily upwards, from the motion of a sailor climbing shrouds on a sailing ship (originally "hand over hand").
With a slow even motion, as when hauling on a line "handsomely".
Handy billy
A loose block and tackle with a hook or tail on each end, which can be used wherever it is needed. Usually made up of one single and one double block.
Hangar deck
An enclosed deck, usually beneath the flight deck, on an aircraft carrier intended for use as a hangar in servicing and storing aircraft.
A fastener attached to the luff of the headsail that attaches the headsail to the forestay. Typical designs include a bronze or plastic hook with a spring-operated gate, or a strip of cloth webbing with a snap fastener.
A harbour or harbor (US), or haven, is a place where ships may shelter from the weather or are stored. Harbours can be man-made or natural.
Harbor of refuge
A place where ships in transit can find shelter from a storm. These are often man-made jetty enclosed areas along a featureless coastline where no nearby natural deep water harbors exist.
A section of otherwise muddy shoreline suitable for mooring or hauling out.
See lee-oh.
Harden in
Haul in the sheet and tighten the sails.[1]
Harden up
Turn towards the wind; sail closer to the wind.
Harness cask
A large usually round tub lashed to a vessel's deck and containing dried and salted provisions for daily use.
Harness tub
See "harness cask".
A hard and long-lasting dry biscuit, used as food on long journeys. Also called ship's biscuit.
Hatchway, hatch
A covered opening in a ship's deck through which cargo can be loaded or access made to a lower deck; the cover to the opening is called a hatch.
1.  To steer (a vessel) closer to the direction of the wind.
2.  To shift forward, i.e., more toward the bow of the vessel.
Hauling wind
Pointing the ship towards the direction of the wind; generally not the fastest point of travel on a sailing vessel.
Hawsepipe, hawsehole or hawse /hɔːz/
The shaft or hole in the side of a vessel's bow through which the anchor chain passes.
An informal term for a merchant ship's officer who began their career as an unlicensed merchant seaman, and so did not attend a traditional maritime academy to earn their officer's licence (see also before the mast).
Large rope used for mooring or towing a vessel.
1.  The forwardmost or uppermost portion of the ship.
2.  The forwardmost or uppermost portion of any individual part of the ship, e.g., the masthead, the beakhead, the stemhead, etc.
3.  The top edge of a sail.[1]
4.  The toilet or latrine of a vessel, which in sailing ships projected from the bows and therefore was located in the "head" of the vessel.
Head boat
A fishing boat that takes recreational fishermen out for a fee paid individually by each person (i.e., per head). A head boat differs from a charter boat, which is a fishing boat that a party of fishermen hires for an agreed-upon period.
Head of navigation
The farthest point above the mouth of a river that can be navigated by ships.
Head rail
A curved rail that extends from the figurehead to the bow of a ship.
Head rope
Part of the bolt rope, at the head of a sail, running from the mast to the sprit.[1]
Head sea
A sea where waves are directly opposing the motion of the ship.
A change in the wind direction which forces the helmsman of a close hauled sailboat to steer away from its current course to a less favorable one. This is the opposite of a lift.
The direction a thing's nose is pointing.
Headsail and Headsails.
Any sail flown in front of the most forward mast. Headsails the collective name for all sails afore the mast. [1]
The spar laced to the head of the topsail. [1]
A vessel's transient, vertical, up-and-down motion.
Heave down
Turn a ship on its side (for cleaning). Also known as Careening
Heaving to
Or Hove to. Stopping a sailing vessel by lashing the helm in opposition to the sails, the vessel will gradually drift to leeward, the speed of the drift depending on the vessel's design.
1.  The lean caused by the wind's force on the sails of a sailing vessel.
2.  The inclination or canting of a vessel to one side or the other from the vertical as she maneuvers, as The ship heeled to port as she turned to starboard.
3.  The lowest or last part of something, such as the heel of the mast or the heel of the vessel.
A ship's steering mechanism; see tiller and ship's wheel. The wheel and/or wheelhouse area. See also wheelhouse. Take the helm, means take over the steering of the vessel.[1]
A person who steers a ship.
Herring buss
A type of seagoing fishing vessel used by Dutch and Flemish herring fishermen from the 15th through the early 19th century.
Highfield lever
A particular type of tentioning lever, usually for running backstays. Their use allows the leeward backstay to be completely slackened so that the boom can be let fully out.
A knot used to tie a rope or line to a fixed object. See also bend.[1]
1.  A fore-and-aft structural member of the hull fitted over the keel to provide a fixing for the garboard planks.
2.  A rough flat scrubbing brush for cleaning a ship's bottom under water.
When the peak of a wave is amidships, causing the hull to bend so the ends of the keel are lower than the middle. The opposite of sagging. Also refers to a permanent distortion of the hull in the same manner caused, over time, by the bow and stern of a ship being less buoyant than the midships section, during the Age of Sail, shipwrights employed a number of different designs of braces to stiffen ships' hulls against this warping.
The height of a fore-and-aft sail as measured next to the mast or stay.
In earlier use, below the orlop deck, the lower part of the interior of a ship's hull, especially when considered as storage space, as for cargo. In later merchant vessels it extended up through the decks to the underside of the weather deck.
A gap in the coverage of newly applied paint, slush, tar or other preservative.
A chunk of sandstone used to scrub the decks. The name comes from both the kneeling position sailors adopt to scrub the deck (reminiscent of genuflection for prayer), and the stone itself (which resembled a Bible in shape and size).
Home port
The port at which a vessel is based. Often confused with the ship's port of registry, which is the port listed in the vessel's registration documents and lettered on her stern and which may differ from her home port. In the cruise ship industry, the term "home port" often is mistakenly used to refer to a ship's port of departure.
Homeward bounder
Deep sea expression for a sail repair, done with large herringbone stitches.[1]
Wooden or metal hoops used to secure the topsail to the topmast so it can be speedily raised or lowered.[1]
A sound signal which uses electricity or compressed air to vibrate a disc diaphragm.
Shaped ends to the chocks where the main horse is bolted.[1]
Horn timber
A fore-and-aft structural member of the hull sloping up and backwards from the keel to support the counter.
1.  Sand lying mid-channel.[1]
2.  Prominent wooden or iron beams lying across the deck of a sailing barge taking the foresheet and mainsheet.[1]
3.  Attachment of sheets to deck of vessel (main-sheet horse).
4.  (v.) To move or adjust sail by brute hand force rather than using running rigging.
Hospital ship
A ship designated and equipped to serve primarily as a floating medical healthcare facility or hospital, usually operated by military forces – mostly navies – for use in or near war zones.
Attachments of stays to masts.[1]
Hotel load
The electrical load for all non-propulsion systems on a ship.
A man who makes his living by claiming salvage on a vessel labouring in a heavy seaway.[27]
1.  A cutter rigged craft, pole masted with a boomless gaff mainsail, with a steeved up bowsprit. They were square swim headed Thames estuary barges of 40 to 150 tons burthen.[28]
2.  Barge making regular passages on a fixed route with mixed third-party cargoes. aka Passage barge, goods barge.[1][28]
Men employed to help the barges crew along tortuous channels or through bridges. See shooting a bridge.[1]
1.  A ship, often an old ship or one that has become obsolete or uneconomical to operate, that has had its rigging or internal equipment removed and is incapable of going to sea, but that is afloat and continues to serve a useful function, such as providing living, office, training, storage, or prison space.
2.  To convert a ship into such a hulk.
3.  Less commonly, a ship that has been launched but not completed.
4.  Also less commonly, an abandoned wreck or shell of a ship.
The shell and framework of the basic flotation-oriented part of a ship.
Of a vessel when only its upper parts are visible over the horizon.
Hull speed
The maximum efficient speed of a displacement-hulled vessel.
A boat with wing-like foils mounted on struts below the hull, lifting the hull entirely out of the water at speed and allowing water resistance to be greatly reduced.


A special-purpose ship or boat designed to move and navigate through ice-covered waters.
A serious hazard where cold temperatures (below about −10°C) combined with high wind speed (typically force 8 or above on the Beaufort scale) result in spray blown off the sea freezing immediately on contact with the ship
Members of a ship's company not required to serve watches. These were in general specialist tradesmen such as the carpenter and the sailmaker.
In ballast (or "in ballast condition")
Of a vessel: Having only ballast (q.v.) – and no cargo – as a load.
In Irons/In stays
When a sailing vessel has lost its forward momentum while heading into the wind, rendering it unable to steer.[1]
In ordinary
An 18th- and 19th-century term originally used to refer to a naval vessel out of service for repair or maintenance, later coming to mean naval ships in reserve with no more than a caretaker crew.
In-water Survey
A method of surveying the underwater parts of a ship while it is still afloat instead of having to drydock it for examination of these areas as was conventionally done.
In way of
In the vicinity of; in the area of.
1.  Situated within a vessel.
2.  Situated within a vessel and positioned close (or closer than another item, when contrasted with that item) to her centerline (q.v.).
3.  Situated outside a vessel but nearer to her hull, e.g., The larger boat was tied up alongside the ship inboard of the smaller boat.
4.  Nearer the pier or shore, e.g., The tanker and cargo ship were tied up at the pier alongside one another with the tanker inboard of the cargo ship.
Inboard motor
An engine mounted within the hull of a vessel, usually driving a fixed propeller by a shaft protruding through the stern. Generally used on larger vessels. See also sterndrive and outboard motor.
Inboard-Outboard drive system
See sterndrive.
Inglefield clip
A type of clip for attaching a flag to a flag halyard.
1.  Near (especially in sight of) or toward the shore.
2.  Of a wind, blowing from the sea to the land.
Iron Mike
A slang term for autopilot.
Iron topsail
An auxiliary motor on a schooner.
Iron wind
What sailors call inboard engines.
A steam-propelled warship protected by iron or steel armor plates of the period from 1859 until the 1890s (when the term "ironclad" fell out of use).
The superstructure of an aircraft carrier that extends above the flight deck. A carrier that lacks one is said to be flush-decked.


1.  A sailor. Also jack tar or just tar.
2.  A national or other official flag flown on a short jackstaff (q.v.) at the bow of a vessel indicating nationality or subordination to a navy or other particular seagoing service or to a government department or subnational government (such as a state or province), or to indicate membership in a yacht club . Typically, crew members spoke of the jack as if it were a member of the crew. A jack contrasts with an ensign (q.v.), which is a flag with a generally similar purpose flown from the vessel′s stern. Typically, vessels fly a jack while in port and an ensign while at sea.
3.  Informally, any flag flown by a ship.
Sometimes spelled jackass bark, is a sailing ship with three (or more) masts, of which the foremast is square-rigged and the main is partially square-rigged (topsail, topgallant, etc.) and partially fore-and-aft rigged (course). The mizzen mast is fore-and-aft rigged.
Jack Dusty
A naval stores clerk.
Jack Tar
A sailor dressed in 'square rig' with square collar. Formerly with a tarred pigtail.
Jacklines or jack stays
Lines, often steel wire with a plastic jacket, from the bow to the stern on both port and starboard. A crewmember clips his safety harness to a jackline, allowing him to walk along the deck while still being safely attached to the vessel.
A small vertical pole on the bow of a vessel on which it flies its jack (q.v.). The jackstaff was introduced in the 18th century.
Iron rod bolted clear of the mainmast, to which the luff of the mainsail is laced. [1]
See genoa
A man-made wall in open water rising several feet above high tide made of rubble and rocks used to create a breakwater, shelter, erosion control, a channel, or other such purpose.
Debris ejected from a ship that sinks or washes ashore. See also Flotsam.
A triangular staysail at the front of a ship. More specifically, one mounted between bowsprit and the head if the mainmast.[1]
A spar used to extend the bowsprit.
See gybe.
See gybe-oh.
The fourth mast, although ships with four or more masts were uncommon, or the aft most mast where it is smallest on vessels of less than four masts.
Traditional Royal Navy nickname for the Royal Marines.
Jolly boat
On a barge, the ship′s boat used to ferry crew and stores when the barge is moored off.[1]
a slender triangular recess cut into the faying surface of a frame or steamed timber to fit over the land of clinker planking, or cut into the faying edge of a plank or rebate to avoid feather ends on a strake of planking. The feather end is cut off to produce a nib, the joggle and nib in this case is made wide enough to allow a caulking iron to enter the seam.
A person (either a sailor or a passenger) who carries a jinx, one whose presence on board brings bad luck and endangers the ship.
1.  Old cordage past its useful service life as lines aboard ship. The strands of old junk were teased apart in the process called picking oakum.
2.  A sailing ship of classic Chinese design with characteristic full batten sails that span the masts usually on unstayed rigs.
Jury rig
Both the act of rigging a temporary mast and sails and the name of the resulting rig. A jury rig would be built at sea when the original rig was damaged, then it would be used to sail to a harbor or other safe place for permanent repairs.


a type of Proa native to Palau.[29]
A technique for moving or turning a ship by using a relatively light anchor known as a kedge. The kedge anchor may be dropped while in motion to create a pivot and thus perform a sharp turn, the kedge anchor may also be carried away from the ship in a smaller boat, dropped, and then weighed, pulling the ship forward.
The central structural basis of the hull.
Maritime punishment: to punish by dragging under the keel of a ship.
See anchor sentinel.
A baulk of timber or steel girder immediately above the keel that forms the backbone of a wooden ship. Chine keelson of more modest proportions are fitted at the junction of the floors and frames.[1]
Weights (often scrap or pig iron) used as permanent high-density ballast.
A two-masted fore-and-aft rigged sailboat with the aft mast (the mizzen) mounted (stepped) afore (in front of) the rudder.
A small anchor. A fouled killick is the substantive badge of non-commissioned officers in the RN. Seamen promoted to the first step in the promotion ladder are called 'Killick', the badge signifies that here is an able seaman skilled to cope with the awkward job of dealing with a fouled anchor.
Kicking strap
1.  A rope, tackle or hydraulic ram running from the mast at or just above deck level to a point part-way along the boom of a yacht's mainsail or mizzen. Its function is to pull the boom down, flattening the sail in strong winds, reducing twist and preventing the boom from kicking up when running.
1.  A chain rigged from the rudder to quarter, tightened when anchored, it relieve the pressure on the gudgeon pin,[1]
King plank
The centerline plank of a laid deck. Its sides are often recessed, or nibbed, to take the ends of their parallel curved deck planks.
Kingston valve
A type of seacock (q.v.) designed so that sea pressure keeps it closed under normal operating conitions, but which can be opened from the inside of the ship, allowing seawater to enter internal fuel, water, or ballast tanks. Kingston valves can be opened to scuttle (q.v.) a ship.
Kissing the gunner's daughter
Bending over the barrel of a gun for punitive beating with a cane or cat.
Kitchen rudder
Hinged cowling around a fixed propeller, allowing the drive to be directed to the side or forwards to manoeuvre the vessel.
1.  Connects two parts roughly at right angles, e.g. deck beams to frames.
2.  A vertical rubber fender used on pushboats or piers, sometimes shaped like a human leg bent slightly at the knee
1.  A mitred backing timber which extends the after line of the rabbet in the stem to give extra support to the ends of the planks and the bowsprit.
2.  A bollard or bitt.
3.  Either of two timbers rising from the keel of a sailing ship and supporting the inner end of the bowsprit.
See Header.
The condition of a sailboat being pushed abruptly to horizontal, with the mast parallel to the water surface.
A unit of speed: 1 nautical mile (1.8520 km; 1.1508 mi) per hour. Originally speed was measured by paying out a line from the stern of a moving boat; the line had a knot every 47 feet 3 inches (14.40 m), and the number of knots passed out in 30 seconds gave the speed through the water in nautical miles per hour. Sometimes "knots" is mistakenly stated as "knots per hour," but the latter is a measure of acceleration (i.e., "nautical miles per hour per hour") rather than of speed.
Know the ropes
A sailor who 'knows the ropes' is familiar with the miles of cordage and ropes involved in running a ship.


To attach a sail to a spar by passing a rope through eyelet holes and around the spar or its jackstay. [1]
On board a ship, all "stairs" are called ladders, except for literal staircases aboard passenger ships. Most "stairs" on a ship are narrow and nearly vertical, hence the name. Believed to be from the Anglo-Saxon word hiaeder, meaning ladder.
Debris that has sunk to the seabed.
Laid up
To be placed in reserve or mothballed. The latter usage is used in modern times and can refer to a specific set of procedures used by the US Navy to preserve ships in good condition.
Great Lakes slang for a vessel which spends all her time on the five Great Lakes.
Land lubber
A person unfamiliar with being on the sea.
An object ashore that is visible from sea and recognizably distinct that is marked on nautical charts for the purpose of fixing position while at sea.
A military rank for a naval recruit, used in the United Kingdom in the eighteenth century and first half of the nineteenth century and in the United States in the nineteenth century and in the early twentieth century.
A rope that ties something off.
Obsolete term for the left side of a ship. Derived from "lay-board" providing access between a ship and a quay, when ships normally docked with the left side to the wharf. Replaced by port side or port, to avoid confusion with starboard.
See By and large.
Lateen sail or Latin-rig
A fore-and-aft triangular sail set on a long yard mounted at an angle to the mast.
Lateral system
A system of aids to navigation in which characteristics of buoys and beacons indicate the sides of the channel or route relative to a conventional direction of buoyage (usually upstream).
1.  Traditionally, a launch was the largest ship's boat carried by a warship.
2.  In modern usage, a large motorboat.
3.  To dispatch a ship down a slipway, prior to fitting-out and commissioning.
To come and go, used in giving orders to the crew, such as "lay forward" or "lay aloft". To direct the course of vessel. Also, to twist the strands of a rope together. To make it to a mark, buoy, or harbor, such as "We will lay the mark".
Lay day
An unexpected delay time during a voyage often spent at anchor or in a harbor. It is usually caused by bad weather, equipment failure or needed maintenance.
Laying down
Laying the keel of a ship in a shipyard to begin her construction.
Lazaret (also Lazarette or Lazaretto)
1.  A small stowage locker at the aft end of a boat.
2.  A ship or building used for quarantine of sick patients.
3.  An area on some merchant ships where provisions are stored.
4.  In modern shipbuilding and on powerboats of all sizes, the location of the steering gear equipment for the vessel.
Lazy jacks, lazyjacks
A network of cordage rigged to a point on the mast and to a series of points on either side of the boom that cradles and guides the sail onto the boom when the sail is lowered.
The after edge of a sail.[1]
1.  A plummet or mass of lead attached to a line, used in sounding depth at sea.
2.  In former usage, to estimate velocity in knots.
Leadline (also sounding line)
An instrument used in navigation to measure water depth; the line attached to a lead.
A sailor who takes soundings with a lead, measuring the depth of water.
A unit of length, normally equal to three nautical miles.
Lee helm
The tendency of a sailboat to turn to leeward in a strong wind when there is no change in the rudder's position. This is the opposite of weather helm and is the result of a dynamically unbalanced condition. See also Center of lateral resistance.
Lee side
The side of a ship sheltered from the wind (cf. weather side).
Lee shore
A shore downwind of a ship. A ship which cannot sail well to windward risks being blown onto a lee shore and grounded.
A large fan shaped wooden board or fin mounted in pairs on the side of a boat. They can be lowered on the lee side of the ship to reduce leeway (similarly to a centerboardon a dinghy).[1]
Leeboard irons
The iron bars that run from the mainmast case to the head of each leeboard, which they support.[1]
Leeboard pendant
A wire connecting the fan of the leeboard, to a winch on the barges quarter. They control the fall of the leeboard. [1]
The aft or trailing edge of a fore-and-aft sail; the leeward edge of a spinnaker; a vertical edge of a square sail. The leech is susceptible to twist, which is controlled by the boom vang, mainsheet and, if rigged with one, the gaff vang. [1]
Lee-oh or hard-a-lee
The command given to come about (tack through the wind) on a sailing boat.
Leeward (/ˈljərd/ in nautical use)
In the direction that the wind is blowing towards.
The amount that a ship is blown leeward by the wind. Also the amount of open free sailing space available to leeward before encountering hazards. See also weatherly.[1]
In navigation, a segment of a voyage between two waypoints.
Length between perpendiculars, also p/p, p.p., pp, LPP, LBP or Length BPP
The length of a vessel along the waterline from the forward surface of the stem, or main bow perpendicular member, to the after surface of the sternpost, or main stern perpendicular member. Believed to give a reasonable idea of the vessel's carrying capacity, as it excludes the small, often unusable volume contained in her overhanging ends.
Length overall, or LOA
The maximum length of a vessel's hull measured parallel to the waterline, usually measured on the hull alone, and including overhanging ends that extend beyond the main bow and main stern perpendicular members. For sailing vessels, this may exclude the bowsprit and other fittings added to the hull, but sometimes bowsprits are included.
Let go and haul
An order indicating that the ship is now on the desired course relative to the wind and that the sails should be trimmed ('hauled') to suit.
Letter of marque and reprisal or just Letter of marque
A warrant granted to a privateer condoning specific acts of piracy against a target as a redress for grievances.
A relatively short period when a sailor is allowed ashore for recreation. See also shore leave.
Lie to
To have the ship's sails arranged so as to counteract each other. A ship in this condition or in the process of achieving this condition is lying to.
Lifebelt, lifebuoy, lifejacket, life preserver, personal flotation device
A device such as a buoyant ring or inflatable jacket which keeps a person afloat in the water.
1.  Shipboard lifeboat, kept on board a vessel and used to take crew and passengers to safety in the event of the ship being abandoned.
2.  Rescue lifeboat, usually launched from shore, used to rescue people from the water or from vessels in difficulty.
An inflatable, covered raft, used in the event of a vessel being abandoned.
An enabling wind shift that allows a close hauled sailboat to point up from its current course to a more favorable one. This is the opposite of a header.
Light irons
Iron bars mounted near the main shrouds which support the navigation lights.[1]
Light screens
Boards on which the navigation lights are hooked, that shield the direction that the red or green light shows.[1]
A flat-bottomed barge used to transfer goods and passengers to and from moored ships, traditionally unpowered and moved and steered using "sweeps" (long oars), with their motive power provided by water currents.
The process of transferring cargo from one vesel to another to reduce the draft of the first vessel. Done to allow a vessel to enter a port with limited depth or to help free a grounded vessel.
Lightvessel or lightship
A permanently anchored vessel performing the functions of a lighthouse, typically in a location where construction of the latter is impractical. These have largely been replaced by buoys or, as construction techniques have improved, actual lighthouses.
The correct nautical term for the majority of the cordage or "ropes" used on a vessel. A line will always have a more specific name, such as mizzen topsail halyard, that specifies its use.
Line astern
In naval warfare, a line of battle formed behind a flagship
1.  During the Age of Sail, a ship-of-the-line, a major warship capable of taking its place in the main battleline of fighting ships.
2.  Any cargo or passenger ship running scheduled service along a specific route with published ports of call, excluding ferries and other vessels engaged in short-sea trading. When referring to cargo ships, liner in this sense contrasts with tramp, which refers to a ship engaged in spot-market trade that does not follow a regular schedule or make regular calls at specific ports. When referring to passenger ships, liner in this sense refers to ships providing scheduled transportation between regular ports of call and excludes cruise ships, which voyage merely for recreational purposes and not primarily as a form of transportation between ports.
3.  Ocean liner: Any large and prestigious passenger ship, including cruise ships.
A vessel's angle of lean or tilt to one side, in the direction called roll. Typically refers to a lean caused by flooding or improperly loaded or shifted cargo (as opposed to 'heeling', which see).
short length of rope with an eye, used to hold another rope in position.[1]
Loaded to the gunwales
Literally, having cargo loaded as high as the ship's rail; also means extremely drunk.
The technique used to convert a scaled drawing to full size used in boat construction.
An iron ball attached to a long handle, used for driving caulking into seams and (occasionally) in a fight. Hence: 'at loggerheads'.
An uncontrollable list caused by inadequate transverse stability in the upright condition.
Long stay
The relative slackness of an anchor chain; this term means taut and extended.
1.  In the Age of Sail, a double-banked open boat carried by a sailing ship, rowed by eight or ten oarsmen, two per thwart, although designed also to be rigged for sailing; more seaworthy than a cutter or dinghy and with a beam greater than that of a gig. Eventually supplanted by the whaleboat.
2.  The largest, and thus the most capable, of boats carried on a ship.
A type of ship invented and used by the Vikings for trade, commerce, exploration, and warfare, evolving over several centuries and appearing in its complete form between the 9th and 13th centuries.
A member of the crew specifically assigned to watch surrounding waters for other vessels, land, objects in the water, hazards, threats, etc. Lookouts usually have duty stations high on a vessel's superstructure or in her rigging in order to enhance their field of view.
Loose cannon
An irresponsible and reckless individual whose behavior (either intended or unintended) endangers the group he or she belongs to. A loose cannon, weighing thousands of pounds, would crush anything and anyone in its path, and possibly even break a hole in the hull, thus endangering the seaworthiness of the whole ship.
Loose footed
A mainsail that is not connected to a boom along its foot.[1]
Lower deck
1.  The deck of a ship immediately above the hold.
2.  In British usage, those members of a ship's company who are not officers, often used in the plural (the lower decks)
The lower brails on the mainsail.[1]
Lubber's hole
A port cut into the bottom of a masthead or top (crow's-nest) allowing easy entry and exit. It was considered "un-seamanlike" to use this method rather than going over the side from the shrouds, and few sailors would risk the scorn of their shipmates by doing so (at least if there were witnesses); in practice, it is actually quicker and easier for a fit sailor to climb outside the masthead rather than through the lubber's hole.
Lubber's line
A vertical line inside a compass case indicating the direction of the ship's head.
1.  The forward edge of a sail.[1]
2.  Process of pointing a sailing vessel closer to the wind.[1]
3.  Fullest or roundest part of ths ships bows.[30][31]
Luff and touch her
To bring the vessel so close to wind that the sails shake.[6]
Luff barge
Old 18th century term for a sailing barge with a rounded bow, and not a swim-head. aka Paddy boat.[32]
Luff up
To steer a sailing vessel more towards the direction of the wind until the pressure is eased on the [sheet].
1.  When a sailing vessel is steered far enough to windward that the sail is no longer completely filled with wind (the luff of a fore-and-aft sail begins to flap first).
2.  Loosening a sheet so far past optimal trim that the sail is no longer completely filled with wind.
3.  The flapping of the sail(s) which results from having no wind in the sail at all.
Lumber hooker
A Great Lakes ship designed to carry her own deck load of lumber and to tow one or two barges. The barges were big old schooners stripped of their masts and running gear to carry large cargoes of lumber.
A small sailing vessel with lug sails set on two or more masts and perhaps lug topsails, widely used as traditional fishing boats, particularly off the coasts of France, England and Scotland.
Lug sail
A four-sided fore-and-aft sail supported by a spar along the top that is fixed to the mast at a point some distance from the center of the spar.
Lying ahull
Waiting out a storm by dousing all sails and simply letting the boat drift.
Lying to
See Lie to.


Mae West
A Second World War personal flotation device used to keep people afloat in the water; named after the 1930s actress Mae West, well known for her large bosom.
Magnetic bearing
An absolute bearing (q.v.) using magnetic north.
Magnetic north
The direction towards the North Magnetic Pole. Varies slowly over time.
Main deck
The uppermost continuous deck extending from bow to stern.
One of the braces attached to the mainmast.
Mainmast (or Main)
The tallest mast on a ship.
The main brails on the mainsail.[1]
Sail control line that allows the most obvious effect on mainsail trim. Primarily used to control the angle of the boom, and thereby the mainsail, this control can also increase or decrease downward tension on the boom while sailing upwind, significantly affecting sail shape, for more control over downward tension on the boom, use a boom vang.
The stay running from the top of the mainmast to the bottom of the foremast, or from the top of the foremast to the ship's stem.
Making way
When a vessel is moving under its own power.
Man-of-war or man o' war
a warship from the Age of Sail
Man overboard!
An emergency call that alerts the crew (q.v.) that someone aboard (q.v.) has gone overboard (q.v.) and must be rescued.
Man the rails
To station the crew of a naval vessel along the rails and superstructure of the vessel as a method of saluting or rendering honors.
Man the yards
To have all of the crew of a sailing vessel not required on deck to handle the ship go aloft and spread out along the yards. Originally used in harbors to display the whole crew to the harbor authorities and the other ships present to show that the vessel's guns were not manned and hence her intentions were peaceful, manning the yards has since became a display used in harbor during celebrations and other special events.
A document listing the cargo, passengers, and crew of a ship for the use of customs and other officials.
Marconi rig
Another term for Bermudan rig. The mainsail is triangular, rigged fore-and-aft with the lead edge fixed to the mast. Refers to the similarity of the tall mast to a radio aerial.
a docking facility for small ships and yachts.
1.  A soldier trained for service afloat in a (primarily) infantry force that specializes in naval campaigns and subordinated to a navy or a separate naval branch of service rather than to an army. Often capitalized (e.g., "a Marine," or "the Marines"). Notable examples are the United Kingdom's Royal Marines, formed as the Duke of York and Albany's Maritime Regiment of Foot in 1664 with many and varied duties including providing guard to ship's officers should there be mutiny aboard, and the US Marine Corps, formed in 1775 as a separate naval service alongside the US Navy. It is incorrect, and often viewed by marines as offensive, to refer to a marine as a "soldier" or "infantryman," as these terms refer to personnel of an army rather than those of a marine force, it also is incorrect, and sometimes considered offensive by both merchant mariners and marines, to refer to merchant mariners (q.v.) as "merchant marines," because merchant mariners are civilian sailors responsible for operating merchant ships and are not marines. Marines sometimes are thought by seamen to be rather gullible, hence the phrase "tell it to the marines," meaning that one does not believe what is being said.
2.  An alternative term for a navy, uncommon in English, but common in other languages.
3.  Of, or pertaining to, the sea (e.g, marine biology, marine insurance, marine life, marine salvage).
4.  A painting representing a subject related to the sea.
A sailor.
1.  Of or related to the sea (e.g., maritime activities, maritime law, maritime strategy).
2.  Bordering on the sea (e.g., maritime provinces, maritime states).
3.  Living in or near the sea (e.g., maritime animals).
4.  Of or relating to a mariner or sailor.
A tool used in ropework for tasks such as unlaying rope for splicing, untying knots, or forming a makeshift handle.
A vertical pole on a ship which supports sails or rigging. If a wooden, multi-part mast, this term applies specifically to the lowest portion.
Mast case
A yatchsmans tabernacle. The iron fitting in which the heel of the mast is mounted.[1]
Mast stepping
The process of raising the mast.
A small platform partway up the mast, just above the height of the mast's main yard. A lookout is stationed here, and men who are working on the main yard will embark from here. See also crow's nest.
1.  The captain of a commercial vessel.
2.  A senior officer of a naval sailing ship in charge of routine seamanship and navigation but not in command during combat.
3.  Master, a former naval rank.
A non-commissioned officer responsible for discipline on a naval ship. Standing between the officers and the crew, commonly known in the Royal Navy as 'the Buffer'.
A traditional Royal Navy term for an ordinary sailor.
Military equipages of all descriptions for the naval services. The bombs, blankets, beans and bulletins of the Navy and Marine Corps. Taken from Nelson's British navy as the US services became professional. Related: Materiel – the military equipages of the Army and Air Force, taken from Napoleon's French army as the US services became professional.
Merchant marine
A collective term for all merchant ships registered in a given country and the civilians (especially those of that nationality) who man them; the ships and personnel in combination are said to constitute that country's merchant marine. Called the merchant navy in the United Kingdom and some other countries.
Merchant mariner
A civilian officer or sailor who serves in the merchant marine (q.v.). Sometimes such personnel are incorrectly called "merchant marines," but both merchant mariners and marines frown on this term; although merchant mariners are part of the merchant marine, they are civilians and are not in any way marines (q.v.), which are a specialized type of military personnel.
Merchant navy
A name bestowed upon the merchant marine (q.v.) of the United Kingdom by King George V, and since adopted by some other countries as well; the merchant navy's personnel are civilians, and the term "merchant navy" does not imply that they or their ships are a part of the navy. Synonymous with the term merchant marine.
Any non-naval passenger- or cargo-carrying vessel, including cargo ships, tankers, and passenger ships but excluding troopships.
Mess or messdeck
1.  An eating place aboard ship.
2.  A group of crew who live and eat together.
Mess deck catering
A system of catering in which a standard ration is issued to a mess supplemented by a money allowance which may be used by the mess to buy additional victuals from the pusser's stores or elsewhere. Each mess was autonomous and self-regulating. Seaman cooks, often members of the mess, prepared the meals and took them, in a tin canteen, to the galley to be cooked by the ship's cooks, as distinct from "cafeteria messing" where food is issued to the individual hand, which now the general practice.
The midway point between a vessel's center of buoyancy when upright and her center of buoyancy when tilted.
Metacentric height (also GM)
A measurement of the initial static stability of a vessel afloat, calculated as the distance between her centre of gravity and her metacenter. A vessel with a large metacentric height rolls more quickly and therefore more uncomfortably for people on board; a vessel with a small metacentric height will roll sluggishly and may face a greater danger of capsizing.
The middle brails on the mainsail, higher than the lowers, and lower than the mains.[1]
The middle section of a vessel with reference to the longitudinal plane, as distinguished from fore or aft. (Compare Amidships.)
1.  During the 17th century, a naval rating for an experienced seaman.
2.  From the 18th century, a naval commissioned officer candidate.
3.  From the 1790s, an apprentice naval officer.
4.  From the 19th century, an officer cadet at a naval academy.
5.  In contemporary British usage, a non-commissioned officer below the rank of lieutenant. Usually regarded as being "in training" to some degree. Also known as 'Snotty'. 'The lowest form of rank in the Royal Navy' where he has authority over and responsibility for more junior ranks, yet, at the same time, relying on their experience and learning his trade from them.
6.  In contemporary American usage, a cadet of either sex at the US Merchant Marine Academy or the US Naval Academy. When plural (Midshipmen), the term refers to the student body of either academy, and more formally as "the Regiment of Midshipmen" for the US Merchant Marine Academy and "the Brigade of Midshipmen" for the US Naval Academy. Midshipmen also is the name of the US Naval Academy's sports teams.
Midshipman's hitch
An alternative to the Blackwall hitch, preferred if the rope is greasy. Made by first forming a Blackwall hitch and then taking the underneath part and placing over the bill of the hook.[33]
Midshipman's nuts
Broken pieces of biscuit as dessert.[34]
Midshipman's roll
A slovenly method of rolling up a hammock transversely, and lashing it endways by one clue.[34]
see nautical mile.
Military mast
Hollow tubular masts used in warships in the last third of the 19th century, often equipped with a fighting top armed with light-caliber guns.
A self-contained explosive device intended to damage or sink surface ships or submarines, designed to be placed in water and left to wait until they are triggered by the approach of, proximity of, or contact with, a surface ship or submarines.
A vessel designed or equipped to detect and destroy individual mines. It differs from a minesweeper (q.v.), which is designed or equipped to clear areas of water of mines without necessarily detecting them first.
A vessel designed or equipped to deploy ("lay") mines.
A vessel designed or equipped to clear areas of water of mines without necessaril detecting them first. It differs from a minehunter (q.v.), which is designed or equipped to detect and destroy individual mines.
1.  A mast on a ketch or yawl, or spritsail barge It can be sloop, gaff of spritsail rig, its posioing affore of abaft the steering post defines the difference between a yawl and a ketch. On a barge its rig determines if she is a muffie or a mulie.[1]
2.  A staysail on a ketch or yawl, usually lightweight, set from, and forward of, the mizzen mast while reaching in light to moderate air.[1]
Mizzenmast (or Mizzen)
The third mast, or mast aft of the mainmast, on a ship.
A massive structure, usually of stone or concrete, used as a pier, a breakwater, or a causeway between places separated by water. May have a wooden structure built upon it and resemble a wooden pier or wharf, but a mole differs from a pier, quay, or wharf in that water cannot flow freely underneath it.
1.  A turreted ironclad warship of the second half of the 19th century characterized by low freeboard, shallow draft, poor seaworthiness, and heavy guns, intended for riverine and coastal operations.
2.  In occasional 19th-century usage, any turreted warship.
3.  A shallow-draft armored shore bombardment vessel of the first half of the 20th century, designed to provide fire support to ground troops, often mounting heavy guns.
4.  Breastwork monitor: A 19th-century monitor designed with a breastwork to improve seaworthiness.
5.  River monitor: A monitor specifically designed for riverine operations, used during the 19th and 20th centuries and more recently than other types of monitor. River monitors generally are smaller and lighter than other monitors.
Monkey bridge
A high platform above the wheelhouse offering better visibility to the operator while maneuvering.
Monkey's fist
a ball woven out of line used to provide heft to heave the line to another location. The monkey fist and other heaving-line knots were sometimes weighted with lead (easily available in the form of foil used to seal e.g. tea chests from dampness) although Clifford W. Ashley notes that there was a "definite sporting limit" to the weight thus added.
1.  To attach a boat to a mooring buoy or post.
2.  To dock a ship.
3.  To secure a vessel with a cable or anchor.
Mooring, also Moorings
A place to moor a vessel.
Mother ship (also mothership and mother-ship)
A vessel which leads, serves, or carries smaller vessels, in the latter case either releasing them and then proceeding independently or also recovering them after they have completed a mission or operation. A mother ship sometimes contrasts with a tender (q.v.), which often (but not necessarily) is a vessel that supports or cares for larger vessels.
A template of the shape of the hull in transverse section. Several moulds are used to form a temporary framework around which a hull is built.
Mould loft
Where the lines of the ship are drawn out full-size and the templates for the timbers are made.
Several turns of light line around the mouth of a hook, to prevent unhooking accidents.[1]
A barge rigged with a spritsail main, and a large gaff rigged mizzen afore the steering wheel. It is sheeted to the saddle chock.[1]
Multipurpose vessel
A cargo ship that has fittings to carry standard shipping containers and retractable tweendecks that can be moved out of the way so that the ship can carry bulk cargo.
Muster Station
The location on a vessel a person goes either during an emergency or a drill to prepare for one. i.e. A Muster Drill. If a person is believed missing, all hands would report to their muster station for a head count.
Iron ban around the mast to hold the heel of the sprit.[1]
M.V. (or MV)
Prefix for "Motor Vessel", used before a ship's name.
M.Y. (or MY)
Prefix for "Motor yacht", used before a yacht's name.


A narrow part of a navigable waterway.
Of or pertaining to sailors, seamanship, or navigation. Maritime.
Nautical chart
Maps designed specifically for navigation at sea. Nautical charts use map projections designed for easy use with hand instruments such as the Mercator projection, and indicate depths, hazards, landmarks, aids to navigation such as buoys, and ashore facilities of interest to mariners. Nautical charts are generally originally published by Government agencies such as NOAA, and are now provided in both print form and digital for use in chartplotters.
Nautical mile
A unit of length corresponding approximately to one minute of arc of latitude along any meridian arc. By international agreement it is exactly 1,852 metres (approximately 6,076 feet).
The British system of authorizing naval construction by an annual bill in Parliament.
1.  Sailors subordinated to a navy trained and equipped to operate ashore temporarily as an organized infantry force, but at other times responsible for the normal duties of sailors aboard ship.
2.  A specialized, permanent force of troops subordinated to a navy and responsible for infantry operations ashore. Although more specialized than sailors trained to operate temporarily as naval infantry and bearing similarities to a marine (q.n.) force or marine corps, such permanent naval infantry forces often lack the full capabilities of a marine force. Naval infantry forces also usually differ from marine forces in being subordinated directly to a navy rather than to a separate branch of naval service such as a marine corps.
All activities related to determining, plotting and tracking the position and course of a ship in order to keep track of its position relative to land while at sea. Navigation Charts have been used since ancient times, and remain in use as backups to modern Satellite Global Positioning Systems. Numerous map projections including the common Mercator projection were developed specifically to make navigation at sea simple to perform with straight-edges and compasses.
Rules of the road that provide guidance on how to avoid collision and also used to assign blame when a collision does occur.
"no"; the opposite of "aye".
Short rope used to bind a cable to the "messenger" (a moving line propelled by the capstan) so that the cable is dragged along too (used where the cable is too large to be wrapped round the capstan itself). During the raising of an anchor the nippers were attached and detached from the (endless) messenger by the ship's boys. Hence the term for small boys: "nippers".
The throat of the mainsail.[1]
No room to swing a cat
The entire ship's company was expected to witness floggings, assembled on deck. If it was very crowded, the bosun might not have room to swing the "cat o' nine tails" (the whip).
See Self-sustaining.
A type of navigational buoy often cone-shaped, but if not, always triangular in silhouette, colored green in IALA region A or red in IALA region B (the Americas, Japan, Korea and the Philippines). In channel marking its use is opposite that of a "can buoy".


Material used for caulking hulls. Often hemp picked from old untwisted ropes.
Ocean liner
See Liner.
the more distant part of the sea as seen from the shore and generally beyond anchoring ground.
1.  Moving away from the shore.
2.  Of a wind, blowing from the land to the sea.
3.  At some distance from the shore; located in the sea away from the coast.
1.  A naval auxiliary ship with fuel tanks which refuels other ships with fuel See Oiler (ship).
2.  The job title of a seaman holding a junior position in a ship's engineering crew, senior only to the engine room wiper (q.v.). See Oiler (occupation)
Oilskins or oilies
Foul-weather clothing worn by sailors.
Old man, (The)
Crew's slang for the captain (master or commanding officer) of a vessel.
Old salt
Slang for an experienced mariner.
On board (sometimes "onboard")
See "aboard".
On station
A ship's destination, typically an area to be patrolled or guarded.
On the hard
A boat that has been hauled and is now sitting on dry land.
Open registry
An organization that will register merchant ships owned by foreign entities, generally to provide a flag of convenience (q.v.).
See in ordinary.
Ordinary seaman
1.  A seaman in the British Royal Navy in the 18th century who had between one and two years of experience at sea. Later, a formal rank in the Royal Navy for the lowest grade of seaman, now obsolete.
2.  The second-lowest rank in the United States Navy from 1797 to 1917, between landsman and seaman. Renamed "seaman second class" in 1917.
3.  The rating for entry-level personnel in the deck department of a ship in the United States Merchant Marine. An ordinary seaman (abbreviated "OS") is considered to be serving an apprenticeship to become an able seaman (q.v.).
Great Lakes term for a vessel primarily used in the transport of iron ore.
Orlop deck
The lowest deck of a ship of the line. The deck covering in the hold.
1.  Situated outside the hull of a vessel.
2.  Situated within a vessel but positioned away (or farther away, when contrasted with another item) from her centerline (q.v.).
3.  Farther from the hull, e.g., The larger boat was tied up alongside the ship outboard of the smaller boat.
4.  Farther from the pier or shore, e.g., The tanker and cargo ship were tied up at the pier alongside one another with the tanker outboard of the cargo ship.
5.  An outboard motor (q.v.).
6.  A vessel fitted with an outboard motor.
Outboard motor
A motor mounted externally on the transom of a small boat. The boat may be steered by twisting the whole motor, instead of or in addition to using a rudder.
The lower part of a sterndrive (q.v.).
A line used to control the shape of a sail.
Outward bound
To leave the safety of port, heading for the open ocean.
To have too great a sail area up to safely maneuver in the current wind conditions.
When tacking, holding a course too long.
Over the barrel
Adult sailors were flogged on the back or shoulders while tied to a grating, but boys were beaten instead on the posterior (often bared), with a cane or cat, while bending, often tied down, over the barrel of a gun, known as Kissing the gunner's daughter.
To sail downwind directly at another ship, stealing the wind from its sails.
Off or outside a vessel. If something or someone falls, jumps, or is thrown off of a vessel into the water, the object or person is said to have gone overboard. See "Man overboard!"
Dangerously steep and breaking seas due to opposing currents and wind in a shallow area, or strong currents over a shallow rocky bottom.
The ceiling of any enclosed space below decks in a vessel, essentially the bottom of the deck above you.
Hauling the buntline ropes over the sails to prevent them from chafing.
Capsized or foundered.
Traditional Royal Navy term for the Captain, a survival from the days when privately owned ships were often hired for naval service.
A cloud or other weather phenomenon that may be indicative of an upcoming storm.


Packet, Packet boat, or Packet ship
1.  Originally, a vessel employed to carry post office mail packets to and from British embassies, colonies and outposts.
2.  Later, any regularly scheduled ship, carrying passengers, as in packet trade.
Packet trade
Any regularly scheduled cargo, passenger and mail trade conducted by ship.
A seaman aboard a ship engaged in packet trade.
A rope attached to the bow of a dinghy, usually used to tow dingy or handle it at dockside, or in water.
The pulsation in and out of the bow and stern plating as the ship alternately rises and plunges deep into the water
1.  Paravane (weapon) – A device stabilized by vanes that functions as an underwater glider and which is streamed from (usually) the bow of a vessel and is towed alongside the vessel so that the cable attaching it to the vessel cuts the moorings of submerged mines.
2.  Paravane (water kite) – A towed underwater object with hydrofoils, of use in commercial and sport fishing, water sports, marine exploration, marine industry, and military operations, sometimes equipped with sensors and also of use in exerting a sideward holding force on a vessel. Also called a water kite.
A method of lifting a roughly cylindrical object such as a spar. One end of a rope is made fast above the object, a loop of rope is lowered and passed around the object, which can be raised by hauling on the free end of rope.
A discussion or conference, especially between enemies, over terms of a truce or other matters.
A movable loop or collar, used to fasten a yard or gaff to its respective mast. Parrel still allows the spar to be raised or lowered and swivel around the mast. Can be made of wire or rope and fitted with beads to reduce friction.
Part brass rags
Fall out with a friend. From the days when cleaning materials were shared between sailors.
Hallway of a ship.
A merchant ship configured primarily for the transportation of cargo but also for the transportation of at least some passengers.
Iron fingers that click into notches in the barrel on a winch to prevent roll-back.[1]
Pay off
To let a vessel's head fall off from the wind (to leeward.)[1]
Filling a seam (with caulking or pitch), lubricating the running rigging; paying with slush (q.v.), protecting from the weather by covering with slush. See also: the devil to pay. (French from paix, pitch)
The officer responsible for all money matters in RN ships including the paying and provisioning of the crew, all stores, tools and spare parts. See also: purser.
1.  The upper aftermost corner of a fore-and-aft sail; used in many combinations, such as peak-halyards, peak-brails, etc.[1]
2.  The narrow part of a vessel's bow, or the hold within it.
3.  The extremity of an anchor fluke; the bill.
The uppermost brails on the mainsail. Upper and lower peaks are normal, but a barge may carry a third set too.[1]
1.  Living in the open ocean rather than coastal or inland waters, (e.g., " a pelagic shark").
2.  Taking place in the open ocean (e.g., "pelagic fishing," "pelagic sealing").
1.  A length of wire or rope secured at one end to a mast or spar and having a block or other fitting at the lower end.
2.  A length of wire or rope hooked to a tackle on leeboards.[1]
3.  An alternate spelling of Pennant.[35]
A long, thin triangular flag flown from the masthead of a military ship (as opposed to a burgee, the flags thus flown on yachts).
Picket boat
A boat on sentry duty, or one placed on a line forward of a position to warn against an enemy advance.
A raised structure, typically supported by widely spread piles or pillars, used industrially for loading and unloading commercial ships, receationally for walking and housing attractions at a seaside resort, or as a structure for use by boatless fishermen. The lighter structure of a pier contrasts with the more solid foundations of a quay or the closely spaced piles of a wharf; in North America, the term "pier" used alone connotes either a pier used (or formerly used) by commercial shipping or one used for fishing, while in Europe the term used alone connotes a recreational pier at a seaside resort.
Pier-head jump
When a sailor is drafted to a warship at the last minute, just before she sails.
Navigator. A specially knowledgeable person qualified to navigate a vessel through difficult waters, e.g. harbour pilot etc.
Pilot boat
A type of boat used to transport maritime pilots between land and the inbound or outbound ships that they are piloting.
Points (or plan) of intended movement. The charted course for a naval unit's movements.
1.  Pinnace (ship's boat), a small, light boat propelled by oars or a sail, used as a tender to larger vessels during the Age of Sail.
2.  Full-rigged pinnace, a small "race built" galleon, squared rigged with either two or three masts.
3.  In modern usage, any small boat other than a launch or lifeboat associated with a larger vessel.
The pin or bolt on which a ship's rudder pivots. The pintle rests in the gudgeon.
Pipe (Bos'n's), or a bos'n's call
A whistle used by Boatswains (bosuns or bos'ns) to issue commands. Consisting of a metal tube which directs the breath over an aperture on the top of a hollow ball to produce high pitched notes, the pitch of the notes can be changed by partly covering the aperture with the finger of the hand in which the pipe is held. The shape of the instrument is similar to that of a smoking pipe.
Pipe down
A signal on the bosun's pipe to signal the end of the day, requiring lights (and smoking pipes) to be extinguished and silence from the crew.
Piping the side
A salute on the bos'n's pipe(s) performed in the company of the deck watch on the starboard side of the quarterdeck or at the head of the gangway, to welcome or bid farewell to the ship's Captain, senior officers and honoured visitors.
An act of robbery or criminal violence at sea by the occupants of one vessel against the occupants of another vessel (thus excluding such acts committed by the crew or passengers of a vessel against others aboard the same vessel). Piracy is distinguished from privateering, which is authorized by national authorities and therefore a legitimate form of war-like activity by non-state actors.
One who engages in an act of piracy.
A vessel's motion, rotating about the beam/transverse axis, causing the fore and aft ends to rise and fall repetitively.
To capsize a boat stern over bow, rather than by rolling over.
To turn a sailing barge in shallow water by dropping the leeboard so it drags in the mud, then putting the helm hard over. Used to enter congested harbours.
To skim over the water at high speed rather than push through it.
Plimsoll line (also national Load Line)
A special marking, positioned amidships, that indicates the draft of the vessel and the legal limit to which the vessel may be loaded for specific water types and temperatures.
Plotting room
see transmitting station.
A unit of bearing equal to one thirty-second of a circle, i.e., 11.25°. A turn of 32 points is a complete turn through 360°.
Point up
To change the direction of a sailboat so that it is more up wind. To bring the bow windward. Also called heading up, this is the opposite of falling off.
Points of sail
The course of a sailing vessel in relation to the direction of the wind, divided into six points: in irons (pointed directly into the wind), close hauled (sailing as close into the direction of the wind as possible), close reach (between close hauled and beam reach), beam reach (perpendicular to the wind), broad reach (wind behind the vessel at an angle), and running downwind or running before the wind (the wind is behind the vessel).
A flat-bottomed vessel used as a ferry, barge, or car float, or a float moored alongside a jetty or a ship to facilitate boarding.
Poop deck
A high deck on the aft superstructure of a ship.
1.  Swamped by a high, following sea.
2.  Exhausted.
The left side of the boat. Towards the left-hand side of the ship facing forward (formerly Larboard). Denoted with a red light at night.[1]
Port of registry
The port listed in a vessel's registration documents and lettered on her stern. Often used incorrectly as a synonym for "home port", meaning the port at which the vessel is based, but which may differ from her port of registry.
Port tack
When sailing with the wind coming from the port side of the vessel. Must give way to boats on starboard tack.
Porthole or port
An opening in a ship's side, esp. a round one for admitting light and air, fitted with thick glass and, often, a hinged metal cover, a window
An obsolete form of nautical chart used prior to the development of lines of latitude and longitude which indicated the distances and bearing lines between ports.
An obsolete alternative form of the rank of captain in the Royal Navy; once achieved promotion thereafter was entirely due to seniority.
Powder hulk
A hulk used to store gunpowder.
Powder magazine
A small room/closet area in the hull of the ship used for storing gunpowder in barrels, or, "kegs", usually located centrally so as to have easy access to the grated loading area. Sometimes may be an enclosed closet with a door, so it can be locked and only the captain would have the key, similar to how rum is stored.
Term used retrospectively after 1906 for a wide variety of steam battleships built between the 1880s and c. 1905 designed with only a few large guns for long-range fire, relying on an intermediate secondary battery used at shorter ranges for most of their offensive power, and having triple-expansion steam engines. They were rendered obsolete by the revolutionary dreadnought battleships which began to appear in 1906 and which differed from predreadnoughts in having steam turbine propulsion and an "all-big-gun" armament layout in which the ship's primary gun power resided in a primary battery of its largest guns intended for use at long range, with other gun armament limited to small weapons intended for defense against torpedo boats and other small warships.
Press gang
Formed body of personnel from a ship of the Royal Navy (either a ship seeking personnel for its own crew or from a 'press tender' seeking men for a number of ships) that would identify and force (press) men, usually merchant sailors into service on naval ships usually against their will.
Preventer (gybe preventer, jibe preventer)
A sail control line originating at some point on the boom leading to a fixed point on the boat's deck or rail (usually a cleat or pad eye) used to prevent or moderate the effects of an accidental jibe.
Principal Warfare Officer
PWO, one of a number of Warfare branch specialist officers.
Prison ship or prison hulk
A vessel used as a prison, often to hold convicts awaiting transportation to penal colonies; particularly common in the British Empire in the 18th and 19th centuries.
Private ship
In British usage, a commissioned warship in active service that is not being used as the flagship of a flag officer. The term does not imply in any way that the ship is privately owned.
A privately owned ship authorised by a national power (by means of a #Letter of marque) to conduct hostilities against an enemy. Also called a private man of war.
A property captured at sea in virtue of the rights of war, as a vessel.
Prize crew
Members of a warship's crew assigned to man a vessel taken as a prize.
Propeller (fixed)
Propeller (folding)
Propeller walk or prop walk
tendency for a propeller to push the stern sideways. In theory a right hand propeller in reverse will walk the stern to port.
a poetical alternative term for bows.
Fibres of old rope packed between spars, or used as a fender.
A mechanical method of increasing force, such as a tackle or lever.[1]
The person who buys, stores and sells all stores on board ships, including victuals, rum and tobacco. Originally a private merchant, latterly a warrant officer.


The aftermost deck of a warship. In the age of sail, the quarterdeck was the preserve of the ship's officers.
Queen's (King's) Regulations
The standing orders governing the British Royal Navy issued in the name of the current Monarch.
1.  A stone or concrete structure on navigable water used for loading and unloading vessels, generally synonymous with a wharf (q.v.), although the solid foundations of a quay contrast with the closely spaced piles of a wharf. When "quay" and "wharf" are used as synonyms, the term "quay" is more common in everyday speech in the United Kingdom, many Commonwealth countries, and the Republic of Ireland, while "wharf" is more commonly used in the United States.
2.  To land or tie up at a quay.
1.  An area alongside a quay.
2.  Having the attribute of being alongside a quay, e.g., "The ship is moored quayside."


Rabbet or rebate /ˈræbət/
A groove cut in wood to form part of a joint.
Acronym for RAdio Detection And Ranging. An electronic system designed to transmit radio signals and receive reflected images of those signals from a "target" in order to determine the bearing and distance to the "target".
Radar reflector
A special fixture fitted to a vessel or incorporated into the design of certain aids to navigation to enhance their ability to reflect radar energy. In general, these fixtures will materially improve the visibility for use by vessels with radar.
To incline from the perpendicular; something so inclined is raked or raking, e.g., a raked or raking stem, stern, mast, funnel, etc.
1.  A weapon consisting of an underwater prolongation of the bow of a vessel to form an armored beak, intended to be driven into the hull of an enemy vessel in order to puncture the hull and disable or sink that vessel.
2.  An armored warship of the second half of the 19th century designed to use such a weapon as her primary means of attack.
3.  To intentionally collide with another vessel with the intention of damaging or sinking her.
4.  To accidentally collide bow-first with another vessel.
Range clock
A clockwork device used aboard a warship to continuously calculate the range to an enemy ship.
Range lights
Two lights associated to form a range (a line formed by the extension of a line connecting two charted points) which often, but not necessarily, indicates the channel centerline. The front range light is the lower of the two, and nearer to the mariner using the range, the rear light is higher and further from the mariner.
1.  In British usage, an enlisted member of a country's navy, i.e., all members of the navy who are not officers or warrant officers.
2.  In contemporary US Navy and US Coast Guard usage, the occupational specialty of an enlisted member of the service.
(also "rattlins" or "ratlins")
The rungs fastened between the shrouds permanently rigged from bulwarks and tops to the mast to form ladders enabling access to the topmasts and yards.[1]
1.  A sailing ship that has been cut down to reduce the number of decks.
2.  To cut down a sailing ship to reduce the number of decks.
Sailing across the wind: from about 60° to about 160° off the wind. Reaching consists of "close reaching" (about 60° to 80°), "beam reaching" (about 90°) and "broad reaching" (about 120° to 160°). See also beating and running.
Reaching Sail
A specifically designed sail for tighter reaching legs. Reaching sails are often used in racing with a true wind angle of 35 to 95 degrees, they are generally used before the wind angle moves aft enough to permit spinnakers to be flown.
Ready about
A call to indicate imminent tacking (see going about).[1]
Receiver of Wreck
A government official whose duty is to give owners of shipwrecks the opportunity to retrieve their property and ensure that law-abiding finders of wreck receive an appropriate reward.
Receiving hulk or receiving ship
A hulk used in harbor to house newly recruited sailors before they are assigned to a crew.
Red Duster
Traditional nickname for the Red Ensign (q.v.), the civil ensign flown by civilian vessels of the United Kingdom.
Red Ensign
A British flag, also known informally as the Red Duster, flown as an ensign by certain British ships. Since 1854, it has been flown by British merchant ships (except for those authorized to fly the Blue Ensign (q.v.)) as the United Kingdom′s civil ensign. Prior to 1864, ships of the Royal Navy′s Red Squadron also flew it, but its naval use ended with the reorganisation of the Royal Navy in 1864.
A passage of two vessels moving in the opposite direction on their port sides, so called because the red navigation light on one of the vessels faces the red light on the other vessel.
Reduced cat
A light version on the cat o'nine tails for use on boys; also called "boys' pussy".
1.  Reefing: To temporarily reduce the area of a sail exposed to the wind, usually to guard against adverse effects of strong wind or to slow the vessel.[1]
2.  Reef: Rock or coral, possibly only revealed at low tide, shallow enough that the vessel will at least touch if not go aground.
Small flat lengths of braided cord attached by eyelets to a sail along the reef band, used to secure the excess fabric after reefing. Typically, a reef point consists of two lengths of cord which taper towards their ends – the narrow end of each is threaded through an eye in the wide end of the other and then the pair are rove through the eyelet in the reef band such that one length hangs before and the other abaft the sail.[36]
Long pieces of rough canvas sewed across the sails to give them additional strength.
Ropes employed in the operation of reefing.[37]
1.  A shipboard refrigerator.
2.  A refrigerated cargo ship, used to carry perishable goods that require refrigeration (also reefer ship)
(Past tense rove) To thread a line through blocks in order to gain a mechanical advantage, such as in a block and tackle.[37]
A series of boat races, usually of sailboats or rowboats, but occasionally of powered boats.
Relative bearing
A bearing relative to the direction of the ship: the clockwise angle between the ship's direction and an object. See also absolute bearing and bearing.
Repair ship
A naval auxiliary ship designed to provide maintenance support to other ships.
Replenishment oiler
A naval auxiliary ship which provides fuel and dry stores to other ships.
Research vessel
A ship designed and equipped to carry out research at sea, especially hydrographic survey, oceanographic research, fisheries research, naval research, polar research, and oil exploration.
Rib tickler
A bargeman's name for the tiller.[1]
Riding light
A light hung from the forestay when at anchor.[1]
The system of masts and lines on ships and other sailing vessels.[37]
Rigging chocks
Thick blocks of wood fixed outside the rails to take the chain plates for the shrouds.[1]
Rigging screw
A bottle screw used to keep wires taut.[1]
Righting couple
The force which tends to restore a ship to equilibrium once a heel has altered the relationship between her centre of buoyancy and her centre of gravity.
The rim or 'eyebrow' above a port-hole or scuttle.
Rip rap
A man-made pile of rocks and rubble often surrounding an off-shore lighthouse or as a base for an aid to navigation.
See roadstead.
A sheltered area outside a harbour where a ship can lie safe at anchor, also known as a roads.
The anchor line, rope or cable connecting the anchor chain to the vessel. Also Anchor Rode.
Rogue wave
A surprisingly large wave for a given sea state; formally, a wave whose height is more than twice the significant wave height (i.e., the mean of the largest third of waves in a wave record).
A vessel's motion rotating from side to side, about the fore-aft/longitudinal axis. Listing is a lasting, stable tilt, or heel, along the longitudinal axis. Roll is also an alternate name for the longitudinal axis (roll axis).
Roll-on/roll-off ship (also RORO or ro-ro)
A vessel designed to carry wheeled cargo that can drive on and off the ship on its own wheels.
A number of pulleys, engaged to confine the yard to the weather side of the mast; this tackle is much used in a rough sea.[38]
Rolling vang
A second set of sprit-head vangs played out forward to rail near the bows, used to give additional control and support when needed in a seaway. [1]
In a convoy, a ship that breaks ranks and "romps" ahead.
Ropes, the
1.  All cordage, the lines in the rigging.
Ropes, the
2.  Cordage of over 1 inches in diameter.[38]
Rope's end
A summary punishment device.
Rope yarn
1.  A period, traditionally on Wednesday afternoons, when a tailor boarded a sailing warship while the vessel was in port; the crew was excused from most duties and had light duty mending uniforms and hammocks and darning socks. When the ship was at sea, the crew similarly was excused from most duties on Wednesday afternoons to engage in mending chores. Wednesday afternoons, like Sundays, thus were a more social time which allowed crewmen a rest from their normal duties, similar to a Sunday, and, because the crew used rope yarn for mending, Wednesday afternoon became known as rope yarn Sunday.
2.  After uniforms began to require less care, and through the mid-20th century, a period on Wednesday afternoon when naval crew members were excused from their regular duties to run personal errands.
3.  Since the mid-20th century, any period of free time when a naval crew is given early liberty or otherwise excused from its normally scheduled duties.
4.  One of threads of which a rope is composed. [38]
RORO or ro-ro
See roll-on/roll-off ship.
Round to
To turn the bow of a vessel into the wind.
see reeve.[37]
Rowlock /ˈrɒlək/
A bracket providing the fulcrum for an oar. See also thole.
1.  In large sailing ships, a mast right above the topgallant mast.
2.  The sail of such a mast.
Rubbing strake
An extra plank fitted to the outside of the hull, usually at deck level, to protect the topsides.
A steering device which can be placed aft, externally relative to the keel or compounded into the keel either independently or as part of the bulb/centerboard.
Part of the anchor winch. This is a serrated iron ring attached to the barrel, to which the pawl is applied to prevent backruns of the anchor chain.[1]
see go-fast boat.
Rummage (obsolete spelling "romage")
1.  A place or room for the stowage of cargo in a vessel.
2.  The act of stowing cargo aboard a vessel.
3.  To arrange (cargo, goods, etc.) in the hold of a vessel; to move or rearrange such goods; the pulling and moving about of packages incident to close stowage aboard a vessel.
4.  To search a vessel for smuggled goods, e.g., "After the long voyage, the customs officers rummaged the ship.
Rummage sale
A sale of damaged cargo (from French arrimage).
1.  The stern of the underwater body of a ship from where it begins to curve upward and inward.
2.  A voyage.
Running before the wind or running
Sailing more than about 160° away from the wind. If directly away from the wind, it's a dead run.
Running backstays
The adjustable backstays of the main mast.[1]
Running gear
The propellers, shafts, struts and related parts of a motorboat.
Running rigging
Rigging used to manipulate sails, spars, etc. in order to control the movement of the ship. Cf. standing rigging.[39]


Safe harbour
A harbour which provides safety from bad weather
Safe haven
A safe harbour, including natural harbours, which provide safety from bad weather or attack.
Saddle chock
A transverse beam placed over the transom with fairleads for mooring warps.[1]
When the trough of a wave is amidships, causing the hull to deflect so the ends of the keel are higher than the middle. The opposite of hogging.
1.  A piece of fabric attached to a vessel and arranged such that it causes the wind to drive the vessel along. It may be attached to the vessel via a combination of mast, spars, and ropes.
2.  The power harnessed by a sail or sails to propel a vessel.
3.  To use sail power to propel a vessel.
4.  A trip in a boat or ship, especially a sailboat or sailing ship.
5.  In American usage, a sail is a tower-like structure on the dorsal (topside) surface of submarines constructed since the mid-20th century which houses periscopes, access trunks for the bridge, etc.; called a fin in European and British Commonwealth countries. It differs from the conning tower of earlier submarines, which was similar in appearance to a sail or fin, but housed instruments and controls from which the periscopes were used to direct the submarine and launch torpedo attacks, functions not performed in a modern sail (or fin).
Sail loft
A large open space used by sailmakers to spread out sails.
A set of drawings showing various sail combinations recommended for use in various situations.
Sailing skiff
see 'skiff'.
A craftsman who makes and repairs sails, working either on shore in a sail loft or aboard a large, ocean-going sailing ship.
London term for sailing barge, or a bargeman.[1]
Sally ship
A method of freeing a vessel grounded on mud in which the crew forms a line and runs back and forth athwartships (q.v.) to cause her to rock back and forth, breaking the mud's suction and freeing her with little or no hull damage. When this is required, the crew is given the order Sally ship!
Great Lakes term for a vessel that sails the oceans.
Salty dog
Slang for a sailor, especially for a seaman in the navy.
A person engaged in salvage of a ship or items lost at sea.
A relatively flat bottomed Chinese wooden boat from 3.5 to 4.5 m long; some with a small shelter and may be used as permanent habitation on inland waters; generally used in coastal areas or rivers and as traditional fishing boats. It is unusual for a sampan to sail far from land as they do not have the means to survive rough weather.
Sampson post
A strong vertical post used to support a ship's windlass and the heel of a ship's bowsprit.
S.B. (or SB)
Prefix for "Sailing Barge", used before a ship's name.
To reduce the area and efficiency of a sail by expedient means (slacking the peak and tricing up the tack) without properly reefing, thus slowing boat speed. Also used in the past as a sign of mourning.
A type of sailing vessel characterized by the use of fore-and-aft sails on two or more masts with the forward mast being no taller than the rear masts, first used by the Dutch in the 16th or 17th century.
1.  A method of preparing an anchor for tripping by attaching an anchor cable to the crown and fixing to the ring by a light seizing (also known as becue). The seizing can be broken if the anchor becomes fouled.
2.  A type of clinker dinghy, characteristically beamy and slow.
3.  An inland racing boat with no keel, a large sail plan, and a planing hull.
This is a specialty sail whose name comes from combining the names spinnaker and Reaching sails and can be used as an upwind genoa sail, reaching sail, or downwind sail.
1.  Propeller.
2.  Propeller-driven (e.g., screw frigate, screw sloop).
A name given by sailors to the lowest clouds, which are mostly observed in squally weather.
A term applied to a vessel when carried furiously along by a tempest.
1.  An oar used for sculling.
2.  A boat propelled by sculling, generally for recreation or racing.
A method of using oars to propel watercraft in which the oar or oars touch the water on both the port and starboard sides of the craft, or over the stern. On sailboats with transom-mounted rudders, forward propulsion can be made by a balanced side to side movement of the tiller, a form of sculling.
Originally a series of pipes fitted through the ship's side from inside the thicker deck waterway to the topside planking to drain water overboard, larger quantities drained through freeing ports, which were openings in the bulwarks.
A small opening, or lid thereof, in a ship's deck or hull.
1.  A barrel with a hole in used to hold water that sailors would drink from. By extension (in modern naval usage), a shipboard drinking fountain or water cooler.
2.  Slang for gossip.
Making a hole in the hull of a vessel or opening seacocks, especially in order to sink a vessel deliberately.
Sea anchor
A stabilizer deployed in the water for heaving to in heavy weather. It acts as a brake and keeps the hull in line with the wind and perpendicular to waves. Often in the form of a large bag made of heavy canvas. See also drogue.
Sea chest
A watertight box built against the hull of the ship communicating with the sea through a grillage, to which valves and piping are attached to allow water in for ballast, engine cooling, and firefighting purposes. Also a wooden box used to store a sailor's effects.
Sea state
The general condition of the free surface on a large body of water with respect to wind waves and swell at a certain location and moment, characterized by statistics, including the wave height, period, and power spectrum. The sea state varies with time, as the wind conditions or swell conditions change.
Sea trial
The testing phase of a boat, ship, or submarine, usually the final step in her construction, conducted to measure a vessel's performance and general seaworthiness before her owners take delivery of her.
High waterproof boots for use at sea. In leisure sailing, known as sailing wellies.
A valve in the hull of a vessel used to allow seawater into or out of the vessel. Seacocks re used to admit seawater for purposes such as cooling an engine, feeding a saltwater faucet, or scuttling (q.v.) a vessel, or to drain a sink or toilet into the sea. In warships, seacocks may be used to flood ammunition magazines with seawater to prevent them from exploding during a fire.
1.  The hunting of seals.
2.  The caulked floor of the hold. (also: ceiling). [1]
Generic term for sailor, or (part of) a low naval rank
Certified for, and capable of, safely sailing at sea.
Second mate
Also called second officer, a licensed member of the deck department of a merchant ship, third – or on some ocean liners fourth – in command; a watchkeeping officer, customarily the ship's navigator. Other duties vary, but the second mate is often the medical officer and in charge of maintaining distress signaling equipment, on oil tankers, the second mate usually assists the chief mate with tank-cleaning operations.
Second officer
See second mate.
London term for sailing barges that sought cargo, carrying cargo for other merchants at a fee, rather than for the owner.[1]
A merchant ship which is able to unload herself without any assistance from a harbor's facilities is self-sustaining, while a ship which requires the assistance of a harbor's facilities to unload herself is non-self-sustaining. Self-sustaining ships are more expensive to build, maintain, and operate than non-self-sustaining ships, but have the advantage of being able to operate in less-developed ports that lack the infrastructure necessary to unload ships.
Great Lakes slang term for a vessel with a conveyor or some other method of unloading the cargo without shoreside equipment.
Sennet whip
A summary punitive implement
Covering a rope with thin line to protect it.[1]
The direction toward which the current is flowing.
Navigational instrument used to measure a ship's latitude.
U-shaped iron, with a screw pin at the open end used for securing stays to sails, allowing easy removal.[1]
Shaft alley
Section of a ship that houses the propulsion shaft, running from the engine room to the stuffing box.
Shakedown cruise
A cruise performed before a ship enters service or after major changes such as a crew change, repair, or overhaul during which the performance of the ship and her crew are tested under working conditions.
Pieces of barrels or casks broken down to save space. They are worth very little, leading to the phrase "no great shakes".
Condition of a crewman involuntarily impressed into service on a ship.
The wheel in a block, which rotates as the rope runs.[1]
The upward curve of a vessel's longitudinal lines as viewed from the side.[1]
Sheer plan
In shipbuilding, a diagram showing an elevation of the ship's sheer viewed from the broadside.
A rope, attached to the clew, used to control the setting of a sail in relation to the direction of the wind. The sheet is often passed through a tackle before being attach to fixed points on the deck, or in the case of a barge, to a traveller on the main horse.[1]
Sheet anchor
Historically, this was the heaviest anchor aboard a sailing ship, to be used only in case of emergency, and located amidships, i.e. in the middle of the ship. In more general usage, this term has come to mean a person or thing that is very reliable in times of emergency.[40] For example, in the first inauguration of Thomas Jefferson, he advocated, “the preservation of the General [Federal] Government in its whole constitutional vigor, as the sheet anchor of our peace at home and safety abroad.”[41]
Shell (in the United Kingdom also fine boat)
An extremely narrow, and often disproportionately long, rowing boat outfitted with long oars, outriggers to hold the oarlocks away from the boat, and sliding seats, specifically designed for racing or exercise.
Shelter deck
An upper deck having no overhead protection from the weather itself, but sheltering the deck below it.
Shift colors
Changing the flag and pennant display when a moored vessel becomes underway, and vice versa. A highly coordinated display that ships take pride in; the desired effect is that of one set of flags vanishing while another set flashes out at precisely the same time. Also, slang for changing out of one's Navy uniform into civilian clothes to go ashore. (The US Navy's newsletter for retired personnel is nicknamed Shift Colors from this reason.)[42]
Shift tides
Sighting the positions of the sun and moon using a sextant and using a nautical almanac to determine the location and phase of the moon and calculating the relative effect of the tides on the navigation of the ship.[43][44]
1.  Noun – Strictly, a three-masted vessel square-rigged on all three masts, or on three masts of a vessel with more than three. Hence a ship-rigged barque would be a four master, square-rigged on fore, main and mizzen, with spanker and gaff topsail only on the Jigger-mast. Generally now used refers to most medium or large vessels outfitted with smaller boats, as a consequence of this, submarines may be larger than small ships, but are called boats because they do not carry boats of their own.
2.  Verb – To bring something aboard swiftly, as in "Ship oars."
A type of sailing warship constructed from the 1600s through the mid-1800s to serve as part of the line of battle; the largest and most powerful warships of the era.
Ship over
Verb – To reenlist. When a sailor extends his or her service another term.
Ship rig
Ship-rigged ship
See full rigged ship.
Ship sloop
A type of sloop-of-war introduced in the 1740s which had three square-rigged masts (in contrast to the brig sloop introduced in the 1770s, which had two masts).
Ship's bell
Striking the ship's bell is the traditional method of marking time and regulating the crew's watches. Each bell (from one to eight) represents a 30-minute period since the beginning of a four-hour watch, for example, in the classical system, "Three bells in the morning watch" represents 90 minutes since the beginning of the morning watch, or 5:30am. "Eight bells" indicates the end of a watch.
Ship's biscuit
See hard tack.
Ship's company
The crew of a ship.
Ship's complement
The number of persons in a ship's crew, including officers.
Ship's husband
Once widely used term, now obsolete, for the man at a dockyard in charge of repairs to a ship. The term derived from the notion that the ship was a "lady" who needed to visit her "husband" when in need of repairs.
A person who designs, builds, and repairs ships, especially wooden ones.
A facility where ships or boats are built and repaired. Routinely used as a synonym for dockyard, although dockyard sometimes is associated more closely with a facility used for maintenance and basing activities, while shipyard sometimes is associated more closely with a facility used in construction.
Shallow water that is a hazard to navigation.
Shoal draught
Shallow draught, making the vessel capable of sailing in unusually shallow water.
Shore leave
Free time given to officers and crew of a naval vessel when they are off duty and allowed to disembark and spend time on land. See also liberty.
Short stay
The relative slackness of an anchor chain; this term means somewhat slack, but not vertical nor fully extended.
1.  To take in the slack of (a rope).
2.  To reduce (sail) by taking it in.
Shot across the bow
A shot fired close to and in front of a moving vessel to warn her to stop, often for boarding.
A rope or cable serving to hold a mast up from side to side.
Standing rigging running from a mast to the sides of a ships to support the mast sideways. The shrouds work with the stays, which run forward and aft, to support the mast's weight.[1]
Sick bay
The compartment reserved for medical purposes.
One of an even-numbered group of seamen posted in two rows on the quarterdeck when a visiting dignitary boards or leaves the ship, historically to help (or even hoist) him aboard.
1.  A side-mounted paddle wheel used for propulsion by a paddle steamer.
2.  Propelled by sidewheels (e.g., "sidewheel steamer").
A paddle steamer propelled by a pair of paddle wheels, one mounted on each side.
A sound signal which uses electricity or compressed air to actuate either a disc or a cup shaped rotor.
Sister ship
A ship of the same class as, and therefore virtually identical in design and appearance to, another ship. Sister ships share an identical or nearly identical hull and superstructure layout, similar displacement, and roughly comparable features and equipment. Often, sister ships become more differentiated during their service lives as their equipment (and, in the case of military ships, their armament) are separately altered.
A downward or sternward projection from the keel in front of the rudder. Protects the rudder from damage, and in bilge keelers may provide one "leg" of a tripod on which the boat stands when the tide is out.
Skeleton crew
A minimal crew, usually employed during an emergency or when a vessel is inactive, generally consisting of the minimum number of personnel required to maintain or operate the vessel.
A small boat, traditionally a coastal or river craft, for leisure or fishing, with a single person or small crew. Sailing skiffs have developed into high performance competitive classes.
The captain of a ship.
A sail set very high, above the royals. Only carried by a few ships.
A small, triangular sail, above the skysail. Used in light winds on a few ships.
Slack tide
That period between rising tide and falling tide. or that period between falling tide and rising tide when there is no tidal induced current.
Slave ship
A large cargo ships specially converted for the transportation of slaves. Also known as a slaver or a Guineaman, the latter term derived from the slave trade involving trafficking to and from the Guinea coast of West Africa.
A slave ship (q.v.).
1.  The cabin hatch on a barge.[45]
1.  To pass a rope around something preparatory to attaching a hoisting or lowering tackle to it.
2.  A band of rope or iron for securing a yard to a mast; chiefly used in the plural, "slings".
1.  A berth for a ship or boat; a place for a ship or boat to moor.
2.  The difference between the theoretical distance traveled per revolution of a vessel's propeller and the actual advance of the vessel.
3.  In marine engineering, the motion of the center of resistance of the float of a paddle wheel or the blade of an oar through the water horizontally.
4.  In marine engineering, the difference between a vessel's actual speed and the speed it would have if the propelling instrument acted upon a solid.
5.  In marine engineering, the velocity relative to still water of the backward current of water produced by the propeller.
6.  In marine insurance, a memorandum of the particulars of a risk for which a policy is to be executed, usually bearing the broker's name and initiated by the underwriters.
A ramp on the shore by which ships or boats can be moved to and from the water. Slipways are used for building and repairing ships and boats, they are also used for launching and retrieving small boats on trailers towed by automobiles and flying boats on their undercarriage.
A small to mid-sized sailboat larger than a dinghy, with one mast bearing a main sail and head sail and located farther forward than the mast of a cutter.
1.  In the 18th and 19th centuries, a small sailing warship carrying 18 or fewer guns with a single continuous gundeck.
2.  In the 18th and 19th centuries, any sailing warship bearing fewer than 20 guns.
3.  In the 19th-century US Navy, the term used for the type of sailing warship known in other navies as a corvette.
4.  In the early and mid-20th century, a small ocean-going warship not intended for fleet deployments, used instead for convoy escort, gunboat duties, etc.
Slop chest
Greasy substance obtained by boiling or scraping the fat from empty salted meat storage barrels, or the floating fat residue after boiling the crew's meal. In the Royal Navy the perquisite of the cook who could sell it or exchange it (usually for alcohol) with other members of the crew. Used for greasing parts of the running rigging of the ship and therefore valuable to the master and bosun.
Slush fund
The money obtained by the cook selling slush ashore. Used for the benefit of the crew (or the cook).
A traditional fishing boat used off the coast of England and the Atlantic coast of America for most of the 19th century and in small numbers up to the mid-20th century. Originally a cutter-rigged sailing boat, after about 1865 lengthened and given a ketch rig, some had a topsail on the mizzen mast, others a bowsprit carrying a jib.
Small bower (anchor)
The smaller of two anchors carried in the bow.
A tree or tree branch fixed in the bottom of a navigable body of water and partially submerged or rising nearly to the surface which can pierce and sink vessels. Also known as a deadhead. Snags were a particularly severe hazard in the 19th and early 20th centuries. To be snagged is to suffer damage from or to be sunk by such a hazard.
A short rope, spliced together at the ends and covered with hide, that is seized to the mast to hold the lower end of a sprit.[46]
A midshipman (Royal Navy slang.)[47]
A form of brig where the gaff spanker or driver is rigged on a "snow mast" a lighter spar supported in chocks close behind the main-mast.
Snug loaded
When all the cargo on a barge is stowed below in the hold and there is nothing on deck. In contrast to carrying a stack.[45]
Soft eye
An eye splice without a thimble fitted.
Speed over ground, speed of the vessel relative to the Earth (and as shown by a GPS). Referenced on many fishing forums.
1.  An acronym for SOund Navigation And Ranging, a method of using sound pulses to detect, range, and sometimes image underwater targets and obstacles or the bed of the sea. See also echo sounding and ASDIC.
2.  The equipment used to conduct such searches, ranging, and imaging.
Measuring the depth of the water. Traditionally done by swinging the lead, now commonly by echo sounding.

1.  A storm from the south west.
2.  A type of waterproof hat with a wide brim over the neck, worn in storms.
A fore-and-aft or gaff-rigged sail on the aft-most mast of a square-rigged vessel and the main fore-and-aft sail (spanker sail) on the aft-most mast of a (partially) fore-and-aft rigged vessel such as a schooner, a barquentine, and a barque.
The aft-most mast of a fore-and-aft or gaff-rigged five masted vessels such as schooners, or barquentines. A full-rigged ship has a spanker sail but not a spanker-mast (see Jigger-mast).
A wooden, in later years also iron or steel pole used to support various pieces of rigging and sails. The big five-masted full-rigged tall ship Preussen (German spelling: Preußen) had crossed 30 steel yards, but only one wooden spar – the little gaff of its spanker sail.
Spar torpedo
A weapon consisting of a bomb placed at the end of a long spar and attached to a boat.
Speaking tube
see communication tube.
Spider band or Spider hoop
An iron band around the base of a mast which holds a set of iron belaying pins.[1]
Finely divided water swept from crest of waves by strong winds.
1.  A large sail flown in front of the vessel while heading downwind.[48]
2.  a headsail set windward when running before the wind. The bargemans spinnaker is his topmast staysail, tacked to the mast, and sheeted round the weather crosstree.[1]
Spinnaker pole
A spar used to help control a spinnaker or other headsail.
To join lines (ropes, cables, etc.) by unravelling their ends and intertwining them to form a continuous line. To form an eye or a knot by splicing.[46]
Splice the mainbrace
A euphemism, it is an order given aboard naval vessels to issue the crew with a drink, traditionally grog. The phrase splice the mainbrace is used idiomatically meaning to go ashore on liberty, intending to go out for an evening of drinking.
Split lugsail
Two sails, foresail and mainsail on a lugsail yard, removing the need to dip the yard around the mast every time the vessel tacked[49]
A projection from the side of a vessel for protection, stability, or the mounting of equipment such as armaments or lifeboats. A sponson that extends a hull dimension at or below the waterline serves to increase flotation or add lift when underway. In salvage of a damaged or disabled vessel, a sponson may be a flotation tank attached to provide stability or buoyancy.
The person, traditionally a woman, who christens a ship at its launching ceremony.
Spotting top
A platform on a mast used to aid in gun laying.
A spar on a sailboat used to deflect the shrouds to allow them to better support the mast.[1]
A line used parallel to that of the length of a craft, to prevent fore-aft motion of a boat, when moored or docked. Also used to assist the barge to swing its head round when leaving.[1]
Big tides caused by the alignment of the moon and sun, occurng abut 15:00 at London Bridge. [45]
A spar, attached by a muzzle to a mast, or held in a snotter, that supports the peak of a spritsail. It is steadied by vangs.[1]
1.  A fore and aft sail, where the peak is supported by a sprit. It may be free-footed or use a boom.
2.  A rig that uses a spritsail.[1]
3.  A square-sail flown beneath the bowsprit.[50]
A spritsail rigged barge[1]
Spurling pipe
1.  In general, any significant group of warships which is considered too small to be designated a fleet, but otherwise not strictly defined by size. In some navies, the term flotilla may be used instead of or in addition to "squadron" to describe a significant group of warships smaller than a fleet.
2.  Such a group of warships assigned to and named after a particular ocean, sea, or geographical region, commanded by an admiral who may be the naval commander-in-chief in that theatre, e.g., the Asiatic Squadron, the North Atlantic Squadron, etc.; generally synonymous with similar naval formations known as stations (q.v.).
3.  During the Age of Sail, a temporary sub-division of a fleet.
4.  A temporary detachment of ships from a fleet.
5.  Especially in the late 19th and early 20th centuries, a permanent battle formation of a fleet, equipped and trained to operate as a tactical unit under the overall command of the fleet or when detached from the fleet.
6.  Especially in modern usage, an administrative naval command responsible for the manning, training, supply, and maintenance of a group of ships or submarines but not for directing their operations at sea.
To place at right angles with the mast or keel and parallel to the horizon e.g., "to square the yards."
Square meal
A sufficient quantity of food. Meals on board ship were served to the crew on a square wooden plate in harbor or at sea in good weather. Food in the Royal Navy was invariably better or at least in greater quantity than that available to the average landsman. However, while square wooden plates were indeed used on board ship, there is no established link between them and this particular term, the OED gives the earliest reference from the US in the mid-19th century.
Square rig
A generic type of sail and rigging arrangement in which the primary driving sails are carried on yards which are perpendicular, or square, to the keel of the vessel and to the masts. A ship mainly so rigged is said to be square-rigged.
Square rigger
A ship which is square-rigged.
Squared away
Yards held rigidly perpendicular to their masts and parallel to the deck. This was rarely the best trim of the yards for efficiency but made a pretty sight for inspections and in harbor, the term is applied to situations and to people figuratively to mean that all difficulties have been resolved or that the person is performing well and is mentally and physically prepared.
Squat effect
The phenomenon by which a vessel moving quickly through shallow water creates an area of lowered pressure under its keel that reduces the ship's buoyancy, particularly at the bow. The reduced buoyancy causes the ship to "squat" lower in the water than would ordinarily be expected, and thus its effective draught is increased.
S.S. (or SS)
Prefix for "Steam Ship", used before a ship's name.
Stack (also funnel)
Deck cargo.[1]
2.  See funnel.
A barge designed to take a large deck cargo, usually of hay of straw needed to feed working horses. [1]
Vertical post near a deck's edge that supports life-lines. A timber fitted in between the frame heads on a wooden hull or a bracket on a steel vessel, approx one meter high, to support the bulwark plank or plating and the rail.
Stand (past tense stood)
Of a ship or its captain, to steer, sail, or steam, usually used in conjunction with a specified direction or destination, e.g., The ship stood out of the harbor or The ship stood toward the east or The ship stood toward the missing vessel's last known position.
Stand-on (vessel)
A vessel directed to keep her course and speed where two vessels are approaching one another so as to involve a risk of collision.
Standing part
The section of a rope at a cleat or a block that is under tension, as opposed to the loose end.[1]
Standing rigging
Rigging which is used to support masts and spars, and is not normally manipulated during normal operations. Cf. running rigging.
A heavy wire cable attached to the mast at the hounds to support the weight of a spritsail at the heel.[1]
The right side of the boat. Towards the right-hand side of a vessel facing forward. [1] Denoted with a green light at night. Derived from the old steering oar or steerboard which preceded the invention of the rudder.
Starboard tack
When sailing with the wind coming from the starboard side of the vessel. Has right of way over boats on port tack.
A rope used as a punitive device. See teazer, togey.
1.  A superior cabin for a vessel's officer.
2.  In American usage, also a private passenger cabin in a vessel
1.  In chiefly 19th- and early 20th-century usage, a naval formation under a commander-in-chief who controls all naval operations, and sometimes all naval shore facilities, within a specified geographic area (e.g., the China Station, the East Indies Station, etc.), sometimes synonymous with squadron (q.v.).
2.  In Newfoundland, a harbour or cove with a foreshore suitable for a facility to support nearby fishing.
3.  Naval station, a naval base; a naval air station is a base for naval aircraft.
4.  Coaling station, a facility that supplies ships with coal.
1.  A strong rope supporting a mast, and leading from the head of one mast down to some other mast or other part of the vessel; rigging running fore (forestay) and aft (backstay) from a mast to the hull. The stays support a mast's weight forward and aft, while the shrouds support its weight from side to side.[51]
2.  To incline forward, aft, or to one side by means of stays, e.g., to stay a mast.
3.  To tack; put on the other tack, e.g., to stay ship.
4.  To change; tack; go about; be in stays, as a ship.
5.  A station or fixed anchorage for vessels.
6.  In stays or hove in stays: in the act of going about while tacking.
7.  Miss stays an unsuccessful attempt to tack.
A flexible wire cable rove through blocks, one on the stemhead, and one on the end of the forestay. This is the means by which the mainmast is lowered.[1]
A sail whose luff is attached to a forestay.[1]
A vessel equipped with steam propulsion. Also steamboat or steamship.
1.  The effect of the helm on a vessel; the act of steering a vessel.
2.  19th- and early 20th-century term for the section of a passenger ship that provided inexpensive accommodation with no individual cabins.
The minimum speed at which a vessel will answer the helm, below which she cannot be steered. Speed sufficient for the rudder to "bite."
Steering flat
In a vessel, the compartment containing the steering gear.
Steering oar or steering board
A long, flat board or oar that went from the stern to well underwater, used to steer vessels before the invention of the rudder. Traditionally on the starboard side of a ship (the "steering board" side).
1.  A spar or derrick with a block at one end, used for stowing cargo.
2.  To incline upwards at an angle (esp. of a bowsprit) rather than lie horizontally; to set at a particular upwards incline
1.  The extension of keel at the forward end of a ship.
2.  On a barge, the foremost timber set vertically to the keel, forming the head of the stem; it carries the forestay and other rigging.[1]
The rear part of a ship, technically defined as the area built up over the sternpost, extending upwards from the counter rail to the taffrail.
Stern chaser
See chase gun.
Stern tube
1.  The tube under the hull to bear the tailshaft for propulsion (usually at stern).
2.  A torpedo tube mounted in the stern of a submarine.
A propeller drive system similar to the lower part of an outboard motor extending below the hull of a larger power boat or yacht, but driven by an engine mounted within the hull. Unlike a fixed propeller (but like an outboard), the boat may be steered by twisting the drive. See also inboard motor and outboard motor.
An external walkway or gallery for the use of officers installed on the stern chiefly of British warships until the early 20th century.
The reverse movement of a boat or watercraft through the water.
1.  A stern-mounted paddle wheel used for propulsion by a paddle steamer.
2.  Propelled by a sternwheel (e.g., "sternwheel steamer").
A paddle steamer propelled by a sternwheel.
A member of a vessel's crew involved in commissary duties or in personal services to passengers or other crew members.
See Stand.
Stopper knot
A knot tied in the end of a rope, usually to stop it passing through a hole; most commonly a figure-eight knot.
A short rope to check a cable in a fixed position. Anchor stoppers hold the anchor when catted, Bitt stoppers, Deck stoppers used to retain the cable when at anchor, shroud stoppers contain a damaged shroud, Foretack and Sheet Stoppers secure the tacks until they are belayed.[52]
(also "store ship" or "stores ship")
1.  During the Age of Sail and immediately afterwards, a captured ship used to stow supplies and other goods for naval purposes.
2.  Since the mid-20th century, a type of naval ship which provides supplies such as frozen, chilled' and dry provisions and propulsion and aviation fuel to warships which are at sea for an extended period of time. In some navies, synonymous with replenishment oiler, fleet replenisher, or fleet tanker.
Stove or Stove in
(past tense of stave, often applied as present tense) to smash inward, to force a hole or break in, as in a cask, door or other (wooden) barrier.
to store, or to put away e.g., personal effects, tackle, or cargo.
The amount of room for storing materials on board a ship.
A trespasser on a ship; a person aboard a ship without permission and/or without payment, and usually boards undetected, remains hidden aboard, and jumps ship just before making port or reaching a port's dock; sometimes found aboard and imprisoned in the brig until the ship makes port and the prisoner can be transferred to the police or military.
In a convoy, a ship that is unable to maintain speed and falls behind.
One of the overlapping boards in a clinker built hull.
An inclined foot rest, attached to the boat, to which a rower may place and in some instances (usually in competition) attach his feet.
1.  To haul down or lower (a flag, mast, etc.).
2.  To surrender the vessel to the enemy, from strike the colors.
3.  To remove a naval vessel's name from a country's naval register (after which the vessel is considered stricken).
Strike the colors
To surrender the vessel to an enemy, from the custom during the Age of Sail of lowering the vessel's ensign to indicate that she is surrendering.
Studding sails /ˈstʌnsəl/
Long and narrow sails, used only in fine weather, on the outside of the large square sails.
1.  A spritsail barge without a topmast. Normal form before 1850, the stumpies sprit was longer than those used in topsail barges, as the mainsail was cut with a higher peak. [1][53]
2.  A tops'l barge underway with out her topsails set. [1]
Speed through (the) water, speed of the vessel relative to the surrounding water (and as shown by a Log). Used in navigation.
1.  Generally, a watercraft capable of independent operations underwater, able to renew its own power and breathing air. A submarine differs from a submersible (q.v.), which has more limited underwater capabilities. By naval tradition, any submarine is referred to informally as a "boat" regardless of its size.
2.  Most commonly, a large, crewed vessel capable of independent underwater operations.
3.  Historically and colloquially, a broad category of vessels capable of submerged operations, including large, crewed submarines but also medium-sized and smaller vessels such as midget submarines and wet subs and vessels which technically are considered submersibles (q.v.) because they require external support, such as remotely operated vehicles and autonomous underwater vehicles.
Submarine depot ship
See submarine tender.
Submarine tender
A naval auxiliary ship designed to supply submarines and support their operations. Known in British English as a submarine depot ship.
A small vehicle designed to operate underwater which requires the support of a surface vessel, a surface platform, a shore team, or a larger undersea vessel such as submarine (q.v.). A submersible contrasts with a submarine, in that a submarine is capable of fully autonomous operations including the generation of its own power and breathing air. However, colloquially, the term "submarine" often is used indiscriminately to refer to any vessel capable of underwater operations, including those which technically are submersibles.
A personal-sized, beach-launched sailing dinghy with a pontoon-type hull, daggerboard, and lateen sail mounted to an un-stayed mast.
The parts of the ship or a boat, including sailboats, fishing boats, passenger ships, and submarines, that project above her main deck. This does not usually include its masts or any armament turrets.
1.  A vessel's transient motion in a fore and aft direction.
2.  To gently slacken a rope, so it slides up the capstan.[52]
Survey vessel
Any type of ship or boat that is used for mapping a body of water's bottom, benthic zone, full water column, and surface for purposes of hydrography, general oceanography, marine salvage, dredging, marine archaeology, or the study of marine habitats.
Abbreviation for Sailing Vessel, used before the ship's name.
1.  A vessel's lateral motion from side to side.
2.  (v) To hoist: "Sway up my dunnage". [54]
A long oar used to steer an unpowered lighter.
To take up the last bit of slack on a line such as a halyard, anchor line or dockline by taking a single turn round a cleat and alternately heaving on the rope above and below the cleat while keeping the tension on the tail.
A barge with a square overhanging bow, like a swimhead lighter. aka Muffies.[1]
A technique to finally tension a halyard, by pulling alternatively on the tail from the cleat and at right angles on the taut standing line.[1]
Swinging the compass
Measuring the accuracy in a ship's magnetic compass so its readings can be adjusted – often by turning the ship and taking bearings on reference points.
Swinging the lamp
Telling sea stories. Referring to lamps slung from the deckhead which swing while at sea. Often used to indicate that the story teller is exaggerating.
Swinging the lead
1.  Measuring the depth of water beneath a ship using a lead-weighted sounding line. Regarded as a relatively easy job, thus:
2.  Feigning illness etc to avoid a hard job.


A large bracket attached firmly to the deck, to which the foot of the mast is fixed. It has two sides or cheeks and a bolt forming the pivot around which the mast is raised and lowered.aka mast case.[1]
1.  A leg of the route of a sailing vessel, particularly in relation to tacking (q.v.) and to starboard tack and port tack (also q.v.).
2.  Hard tack: q.v..
3.  The front bottom corner of a sail.[1]
1.  Zig-zagging so as to sail directly towards the wind (and for some rigs also away from it).
2.  Going about (q.v.).
Tacking duels
In sailboat racing on an upwind leg of the race course the complex manoeuvres of lead and overtaking boats to vie for the aerodynamic advantage of clear air. This results from the ongoing strategy of the lead boat's effort to keep the following boat(s) in the blanket of disturbed bad air he is creating.
A pair of blocks through which is rove a rope to provide an advantageous purchase. Used for lifting heavy loads and to raise and trim sails. [1]
Tactical diameter
The perpendicular distance between a ship's course when the helm is put hard over and her course when she has turned through 180 degrees; the ratio of the tactical diameter divided by the ship's length between perpendiculars gives a dimensionless parameter which can be used to compare the manoeuvrability of ships.
A rail at the stern of the boat that covers the head of the counter timbers.
The loose end of a rope that has been secured to a winch or a cleat.[1]
A kind of metallic shafting (a rod of metal) to hold the propeller and connected to the power engine. When the tailshaft is moved, the propeller may also be moved for propulsion.
Taken aback
An inattentive helmsmen might allow the dangerous situation to arise where the wind is blowing into the sails 'backwards', causing a sudden (and possibly dangerous) shift in the position of the sails.
Taking the wind out of his sails
To sail in a way that steals the wind from another ship. cf. overbear.
Tall ship
A tall ship is a large, traditionally-rigged sailing vessel.
The operation of hauling aft the sheets, or drawing them in the direction of the ship's stern.
Tanker (also tank ship or tankship)
A ship designed to transport liquids in bulk.
Target ship
A vessel, typically an obsolete or captured warship, used for naval gunnery practice or for weapons testing. The term includes both ships intended to be sunk and ships intended to survive and see repeated use as a target.
Task Force
Temporary naval organisations composed of particular ships, aircraft, submarines, military land forces, or shore service units, assigned to fulfill certain missions. Seemingly drawn originally from Royal Navy heritage, the emphasis is placed on the individual commander of the unit, and references to 'CTF' are common for "Commander Task Force".
Tattle Tale
Light cord attached to a mooring line at two points a few inches apart with a slack section in between (resembling an inch-worm) to indicate when the line is stretching from the ship's rising with the tide. Obviously only used when moored to a fixed dock or pier and only on watches with a flood tide.
Tell-tale (sometimes tell-tail)
A light piece of string, yarn, rope or plastic (often magnetic audio tape) attached to a stay or a shroud to indicate the local wind direction. They may also be attached to the surface and/or the leech of a sail to indicate the state of the air flow over the surface of the sail, they are referenced when optimizing the trim of the sails to achieve the best boat speed in the prevailing wind conditions. (See dogvane)
1.  A type of naval auxiliary ship (q.v.) designed to provide advanced basing services in undeveloped harbors to seaplanes, flying boats, torpedo boats, destroyers, or submarines.
2.  A vessel used to provide transportation services for people and supplies to and from shore for a larger vessel, sometimes called a ship's tender.
3.  A vessel used to maintain navigational aids, such as buoys and lighthouses.
T.E.V. (or TEV)
Prefix for "Turbo-Electric Vessel," used before a ship's name.
A structure or section of a steamboat that includes the pilothouse and the crew's quarters, located on the hurricane deck, in this case also called the texas deck.
Texas deck
The deck of a steamboat on which its texas (q.v.) is located. Also known as a hurricane deck.
Third mate
Also called the third officer, a licensed member of the deck department of a merchant ship, fourth – or on some ocean liners fifth – in command; a watchkeeping officer, customarily also the ship's safety officer, responsible for the ship's firefighting equipment, lifeboats, and other emergency systems. Other duties of the third mate vary depending on the type of ship, its crewing, and other factors.
Third officer
See third mate.
Vertical wooden peg or pin inserted through the gunwale to form a fulcrum for oars when rowing. Used in place of a rowlock.
1.  The forward top corner of a square fore and aft sail.[1]
2.  The end of the gaff, next to the mast. [55]
Three sheets to the wind
On a three-masted ship, having the sheets of the three lower courses loose will result in the ship meandering aimlessly downwind. Also, a sailor who has drunk strong spirits beyond his capacity.
Thwart /θwɔːrt/
A bench seat across the width of an open boat.
Tilt boat
A square sail ferry operating out of Gravesend.Not less than 15 tons, carrying no more that 37 passengers it had 5 oarsmen afore the mast.[56]
From the French timonnier, is a name given, on particular occasions, to the steersman of a ship.
Tin can
US Navy slang for a destroyer; often shortened to can (q.v.).
A lightly armored steam-powered river gunboat used by the US Navy during the American Civil War (1861–1865).
A thin temporary patch.
A lever used for steering, attached to the top of the rudder post. Used mainly on smaller vessels, such as dinghies and rowing boats.
A low strip running around the edge of the deck like a low bulwark. It may be shortened or have gaps in it to allow water to flow off the deck.
Toe the line or Toe the mark
At parade, sailors and soldiers were required to stand in line, their toes in line with a seam of the deck.
A block of wood inserted into the barrel of a gun on a 19th-century warship to keep out the sea spray; also used for covers for the ends of the barrels of more modern ships' guns, the larger of which are often adorned with the ship's crest or other decoration.

Various measures of the size or cargo carrying capacity of a ship, including:

1. Deadweight tonnage, the total weight of a vessel, mostly without payload.

2.  Displacement tonnage, the total weight of a vessel.
3.  Gross register tonnage, the total internal volume of a vessel, with one gross register ton equal to 100 cubic feet (2.8316846592 cubic meters).
4.  Gross tonnage, a function of the volume of all of a ship's internal spaces.
5.  Lightship or lightweight tonnage, the weight of a ship without any fuel, cargo, supplies, water, passengers, etc. on board.
6.  Net register tonnage, the volume of cargo a vessel can carry.
7.  Net tonnage, the volume of all cargo spaces on a ship.
8.  Thames Measurement tonnage, the volume of a small vessel calculated based on her length and beam.
The platform at the upper end of each (lower) mast of a square-rigged ship, typically one-fourth to one-third of the way up the mast. The main purpose of a top is to anchor the shrouds of the topmast that extends above it. See also fighting top.[57]
The mast or sails above the tops. (See topgallant mast and topgallant sail.)
1.  A collective term for the masts, yards, sails and rigging of a sailing ship, or for similarly insubstantial structures above the upper deck of any ship.[58]
2.  Unnecessary spars and rigging kept aloft on a vessel′s masts.
A crewmember stationed in a top.
The second section of the mast above the deck; formerly the upper mast, later surmounted by the topgallant mast; carrying the topsails.
Topmast pole
Part of the spar between the hounds and the truck.[1]
Topping lift
A line which is part of the rigging on a sailing boat; it applies upward force on a spar or boom. The most common topping lift on a modern sailing boat is attached to the boom[57]
The second sail (counting from the bottom) up a mast. These may be either square sails or fore-and-aft ones, in which case they often "fill in" between the mast and the gaff of the sail below.
The part of the hull between the waterline and the deck. Also, Above-water hull
1.  Prior to about 1900, the term for a variety of explosive devices designed for use in water, including mines, spar torpedoes and, after the mid-19th century, "automotive," "automobile," "locomotive," or "fish" torpedoes (self-propelled weapons which fit the modern definition of "torpedo").
2.  Since about 1900, a term used exclusively for a self-propelled weapon with an explosive warhead, launched above or below the water surface, propelled underwater towards a target, and designed to detonate either on contact with its target or in proximity to it.
Touch and go
1.  The bottom of the ship touching the bottom, but not grounding.
2.  Stopping at a dock or pier for a very short time without tying up, to let off or take on crew or goods.
3.  Practice of aircraft on aircraft carriers touching the carrier deck and taking off again without dropping hooks.
The operation of drawing a vessel forward by means of long lines.
Traffic Separation Scheme
Shipping corridors marked by buoys which separate incoming from outgoing vessels. Improperly called Sea Lanes.
A decorative board at the bow of a vessel, sometimes bearing the vessel's name.
Training ship
A ship used to train students as sailors, especially a ship employed by a navy or coast guard to train future officers. The term refers both to ships used for training at sea and to old, immobile hulks used to house classrooms.
Tramp freighter
A cargo ship engaged in the tramp trade.
Tramp steamer
A steamship engaged in the tramp trade.
Tramp trade
Shipping trade on the spot market in which the vessels involved do not have a fixed schedule or itinerary or published ports of call. This contrasts with freight liner service, in which vessels make regular, scheduled runs between published ports.
A vessel engaged in the tramp trade.
Transmitting station
British term for a room located in the interior of a ship containing computers and other specialised equipment needed to calculate the range and bearing of a target from information gathered by the ship's spotters and range finders. These were designated "plotting rooms" by the US Navy.[59]
Lateral members fasten inside the sternpost, to which the hull and deckplanks are fitted.[1]
2.  The aft "wall" of the stern; often the part to which an outboard unit or the drive portion of a sterndrive is attached.
3.  A more or less flat surface across the stern of a vessel. Dinghies tend to have almost vertical transoms, whereas yachts' transoms may be raked forward or aft.
See troopship.
1.  Small fittings that slide on a rod or line. The most common use is for the inboard end of the mainsheet.
2.  A more esoteric form of traveller consists of "slight iron rings, encircling the backstays, which are used for hoisting the top-gallant yards, and confining them to the backstays".
An iron ring that moves on the main horse on a sailing barge. It is fitted with an eye onto which is hooked the main sheet, of the loose-footed main-sail.[1]
1.  Commercial trawler, a fishing boat that uses a trawl net or dragnet to catch fish.
2.  A fisherman who uses a trawl net.
3.  Naval trawler, a converted trawler, or boat built in that style, used for naval purposes.
4.  Recreational trawler, a pleasure boat built in the style of a trawler.
Treenail (also trenail, trennel, or trunnel)
A wooden peg, pin, or dowel used to fasten pieces of wood together, particularly the hull, gunnels, thwarts, etc.[57]
To haul and tie up by means of a rope, to make it less inconvenient.[60]
A period of time spent at the wheel ("my trick's over").
1.  Relationship of ship's hull to waterline.
2.  Adjustments made to sails to maximize their efficiency.
A vessel with three hulls.
Trimmer, sometimes Coal trimmer
person responsible for ensuring that a vessel remains in 'trim' (that the cargo and fuel are evenly balanced). An important task on a coal-fired vessel, as it could get 'out-of-trim' coal is consumed.
Operating as a troopship.
Troopship (also troop ship, troop transport, or trooper)
A ship used to carry soldiers. Troopships are not specially designed for military operations and unlike landing ships cannot land troops directly onto a shore; instead they unload troops at a harbor or onto smaller vessels for transportation to shore.
1.  A circular disc or rectangle of wood or a wooden ball or bun-shaped cap near or at the top of a wooden mast, usually with holes or sheaves in it through which signal halyards (q.v.) can be passed. Trucks are also used on wooden flagpoles to keep them from splitting, the main truck is located on the main mast, the mizzen truck on the mizzen mast, and so on.
2.  A temporary or emergency place for a lookout.
True bearing
An absolute bearing (q.v.) using true north.
True north
The direction of the geographical North Pole.
Tug or tugboat
A boat that maneuvers other vessels by pushing or towing them. Tugs are powerful for their size and strongly built, and some are ocean-going.
Hull shape, when viewed in a transverse section, where the widest part of the hull is someway below deck level.
A knot passing behind or around an object.
Turn To (Turn Two)
A term meaning "Get to work," often hand-signed by two fingers and hand motion in turning fashion.
see bottlescrew.
1.  Originally (in the mid-to-late 19th century), an enclosed armored rotating cylindrical box mounting guns which fired through gunports, the turret rotating over a bearing mounted on a ship's deck or within her hull. Turret-equipped ships contrasted sharply with those equipped with barbettes, which in the second half of the 19th century were open-topped armored rings over which rotating gun(s) mounted on a turntable could fire.
2.  Since the late 19th century, an enclosed armored rotating gunhouse mounted above a barbette, with the gun(s) and their rotating turntable mounted in the barbette protected by the gunhouse; in 20th- and 21st-century usage, this generally is any armored, rotating gun installation on a warship.
Turtleback deck
A deck that has slight positive curvature when viewed in cross-section. The purpose of this curvature is usually to shed water, but in warships it also functions to make the deck more resistant to shells.
In dinghy sailing especially (but can include other boats), a boat is said to be turtling or to turn turtle when the boat is fully inverted with the mast pointing down to the lake bottom or seabed.[A] [62][63]
A deck on a general cargo ship located between the main deck (or weather deck) and the hold space. A general cargo ship may have one or two tweendecks (or none at all).
Tweendeck space
The space on a tweendeck available for carrying cargo or other uses.
A general cargo ship equipped with one or more tweendecks.
Two six heave
Royal Navy slang term meaning to pull. Originally a sailing navy term referring to the two members of a gun crew (numbers two and six) who ran out the gun by pulling on the ropes that secured it in place.
Two blocks
When the two blocks in a tackle have become so close that no further movement is possible as in chock-a-block. [1]
A chain or rope used for hoisting or lowering a yard. A tye runs from the horizontal center of a given yard to a corresponding mast and from there down to a tackle. Sometimes specifically called a chain tye or a rope tye.


Unassisted sailing
A voyage, usually singlehanded, with no intermediate port stops or physical assistance from external sources.
Under the weather
Serving a watch on the weather side of the ship, exposed to wind and spray.
Under way or underway
A vessel that is moving under control: that is, neither at anchor, made fast to the shore, aground nor adrift. Way refers to speed sufficient to steer with the rudder. "Under weigh" is an erroneous synonym.[1]
Underwater hull or underwater ship
The underwater section of a vessel beneath the waterline, normally not visible except when in drydock or (historically), careened.
Underway replenishment
A method employed by navies to transfer fuel, munitions, and stores from one ship to another while underway. Sometimes abbreviation as UNREP.
Unable to navigate, probably on course. 19th century term used in log books of vessels left without accurate navigational guidance, due to poor visibility and/or proximity to the North Pole. Dropped out of common usage in the 1950s with improvements in maritime navigational aids.
To pull a rope from a sheave or block.[1]
1.  To remove from a vessel.
2.  To remove an oar or mast from its normal position
The relative slackness of an anchor chain where the anchor chain is slack and hangs vertically down from the hawsepipe.
Slack off quickly and run slack to a belaying point. This order is given when a line or wire has been stopped off or falls have been four-in-hand and the hauling part is to be belayed.
1.  A vessel traveling upstream.
2.  Westward-traveling vessels in the Great Lakes region (terminology as used by the St. Lawrence Seaway Development Corporation).
The brails above the mains synonym of 'Peaks'.[1]
Specially selected personnel .


The shape of a boat or ship in which the contours of the hull come in a straight line to the keel.
1.  A rope (line) leading from gaff to either side of the deck, used to prevent the gaff from sagging.
2.  One of a pair of ropes leading from the deck to the head of a spritsail. It steadies the sprit and can control the sails performmance during a tack, the vang fall blocks are mounted slightly afore the main horse while rolling vangs are extra preventers lead forward to keep the sail to leeward in heavy weather[1]
3.  See boom vang.
4.  See gaff vang.
Vanishing angle
The maximum degree of heel after which a vessel becomes unable to return to an upright position.
Veer away
To let go a rope gently [60]
Any craft designed for transportation on water, such as a ship or boat.
A large rope used to unmoor or heave up the anchor. [60]
Voice pipe or voice tube
see communication tube.
1.  A long journey by ship.
2.  To go on such a journey.
see viol. [60]


A signal flag on a vessel.
The central deck of a ship between the forecastle and the quarterdeck.[64]
Turbulence behind a vessel. Not to be confused with wash.
Any of the strong and thick planks running lengthwise along a vessel, forming the lower part of the vessel's sides.[1]
1.  The living quarters of a naval ship designated for the use of commissioned officers other than the captain.
2.  A collective term for the commissioned officers of a naval ship excluding her captain; e.g., The captain rarely referred to his wardroom for advice, and this led to their discontent.
1.  To move a vessel by hauling on a line or cable that is fastened to an anchor or pier; especially to move a sailing ship through a restricted place such as a harbour.[65]
2.  A line or cable used in warping a ship.[1]
3.  The length of the shrouds from the bolster to the deadeye[65]
The waves created by a vessel. Not to be confused with wake.
A period of time during which a part of the crew is on duty. Changes of watch are marked by strokes on the ship's bell.
The allocation of crew or staff to a watch.
Water kite
See paravane (definition 2).
Water transport vessels. Ships, boats, personal water craft, etc.
The line where the hull of a ship meets the water's surface.
A sail hung below the boom on gaff rig boats for extra downwind performance when racing.
1.  Waterway, a navigable body of water.
2.  A strake of timber laid against the frames or bulwark stanchions at the margin of a laid wooden deck, usually about twice the thickness of the deck planking.
Speed, progress, or momentum, or more technically, the point at which there is sufficient water flow past a vessel's rudder for it to be able to steer the vessel (i.e., the rudder begins to "bite," sometimes also called "steerage way.") To make way is to move; to "have way on" or "to have steerage way" is to have enough speed to control the vessel with its rudder; to lose way is to slow down or to not have enough speed to control with the rudder. "Way enough" is a coxswain's command that the oarsmen stop rowing, and allow the boat to proceed with its existing way.
An intermediate stop along the route of a steamboat.
The verb's origin, from wegelage, means "lying in wait, with evil or hostile intent." so to be waylaid referred to a ship taken off its course, route, or way, by surprise, typically by unfortunate or nefarious means. In H. Melville's novel, 'Moby Dick', the great white whale waylaid the ship and sank it with only a few souls surviving in lifeboats.[66]
A location defined by navigational coordinates, especially as part of a planned route.
The timbers of shipyard stocks that slope into the water and along which a ship or large boat is launched. A ship undergoing construction in a shipyard is said to be on the ways, while a ship scrapped there is said to be broken up in the ways.
Wearing ship
Tacking away from the wind in a square-rigged vessel. See also gybe.
Weather deck
Whichever deck is that exposed to the weather – usually either the main deck or, in larger vessels, the upper deck.
Weather gage or weather gauge or weather-beam
Favorable position over another sailing vessel with respect to the wind.
Weather helm
The tendency of a sailboat to turn to windward in a strong wind when there is no change in the rudder's position. This is the opposite of lee helm and is the result of a dynamically unbalanced condition. See also Center of lateral resistance.
Weather ship
Weather side
The side of a ship exposed to the wind.
A ship that is easily sailed and maneuvered; makes little leeway when sailing to windward.
Weigh anchor
To heave up (an anchor) preparatory to sailing.[1]
Place in the ship's hold for pumps.
Properly set up or provisioned.
Wetted area
In sailboating, portion of the hull immersed in water.
1.  A type of cargo steamship of unusual design formerly used on the Great Lakes of North America, notably for carrying grain or ore. The hull continuously curved above the waterline from vertical to horizontal, and when the ship was fully loaded, only the rounded portion of her hull (the "whaleback" proper) was visible above the waterline, with sides curved in towards the ends, whalebacks had a spoon bow and a very convex upper deck.
2.  A type of high-speed launch first designed for the Royal Air Force during World War II, or certain smaller rescue and research vessels most common in Europe that, like the Great Lakes vessels, have hulls that curve over to meet the deck, although the "whaleback" designation comes not from the curve along the gunwale as in the Great Lakes vessels, but from the fore-and-aft arch in the deck.
3.  A sheltered portion of the forward deck on certain British fishing boats designed, in part, so that water taken over the bow is more easily shed over the sides. The feature has been incorporated into some pleasure craft – aboard which it is known as a whaleback deck – based on the hull design of older whaling boats.
1.  A type of open boat that is relatively narrow and pointed at both ends, enabling it to move either forwards or backwards equally well.
2.  On modern warships, a relatively light and seaworthy boat for transport of ship's crew.
3.  A type of vessel designed as a lifeboat or "monomoy" used for recreational and competitive rowing in the San Francisco Bay area and coastal Massachusetts.
4.  Informally, any whaler of any size.
5.  Informally, any vessel engaged in whale watching.
1.  A specialized vessel designed for catching or processing whales.
2.  A person engaged in the catching or processing of whales.
A structure on the shore of a harbor or on the bank of a river or canal where ships may dock to load and unload cargo or passengers. Such a structure includes one or more berths (i.e., mooring locations), and may also include piers, warehouses, or other facilities necessary for handling the ships. The term "wharf' is generally synonymous with "quay" (q.v.), although the solid foundations of a quay contrast with the closely spaced piles of a wharf. When "quay" and "wharf" are used as synonyms, the term "quay" is more common in everyday speech in the United Kingdom, many Commonwealth countries, and the Republic of Ireland, while "wharf" is more commonly used in the United States.
Wheel or ship's wheel
The usual steering device on larger vessels: a wheel with a horizontal axis, connected by cables to the rudder.
Location on a ship where the wheel is located; also called pilothouse or bridge.
A small sailing pram.
A type of boat traditionally used for carrying cargo or passengers on rivers and canals in England, particularly on the River Thames and the Norfolk and Suffolk Broads.
A chiefly British term for a narrow clinker-built skiff having outriggers, for one oarsman.
A small single block tackle, used to raise light loads from a hold [65]
Whip upon whip
Connecting two whips together. This runs more smoothly than using a double block with single block tackle which would have the equivalent purchase. Can be used for topsail and top-gallant halliards.[65]
The binding with twine of the loose end of a rope to prevent it unravelling.[1]
A vertical lever connected to a tiller, used for steering on larger ships before the development of the ship's wheel.
Spreaders from the bows to spread the bowsprit shrouds.
One of the pair of stays that stabilize the bowsprit horizontally affixed to forward end of the bowsprit and just aft the stem.
White horses or whitecaps
Foam or spray on wave tops caused by stronger winds (usually above Force 4).
White Ensign
A British flag flown as an ensign by certain British ships. Prior to 1864, ships of the Royal Navy′s White Squadron flew it; since the reorganisation of the Royal Navy in 1864, it has been flown by 1) all Royal Navy ships and shore establishments, 2) yachts of members of the Royal Yacht Squadron, and 3) ships of Trinity House escorting the reigning monarch of the United Kingdom.
Wide berth
To leave room between two ships moored (berthed) to allow space for manoeuvre.
A small hand operated horizontal geared drum, used to assist in the handling of running gear – wire or rope.[1]
Sea conditions with a tidal current and a wind in opposite directions, leading to short, heavy seas.
Wind resistance of the boat.
A condition wherein the ship is detained in one particular station by contrary winds.
Winding tackle
A tackle formed of two triple blocks or a triple and a double, used to raise heavy loads such as guns and anchors [65]
A large iron- or steel-hulled square-rigged sailing ship of the late 19th and early 20th centuries with three, four, or five masts, built mainly between the 1870s and 1900 to carry cargo on long voyages.
A winch mechanism, usually with a horizontal axis. Used where mechanical advantage greater than that obtainable by block and tackle was needed (such as raising the anchor on small ships).[65]
A wide tube or funnel of canvas, used to convey a stream of air into the lower compartments of a ship for ventilation.
In the direction that the wind is coming from.
An extension on the side of a vessel. A bridge wing is an open-air extension of the bridge to port or starboard, intended for use in signaling.
The most junior rate among personnel who work in the engine room of a ship, responsible for cleaning the engine spaces and machinery and assisting the engineers as directed. A wiper is considered to be serving an apprenticeship to become an oiler (q.v.).
Working up
Training, usually including gunnery practice.
Worm, parcel and serve
To protect a section of rope from chafing by: laying yarns (worming) to fill in the cuntlines, wrapping marline or other small stuff (serving) around it, and stitching a covering of canvas (parceling) over all.[67]


A recreational boat or ship; the term includes sailing yachts, motor yachts, and steam yachts.
1.  Yard: The horizontal spar from which a square sail is suspended.[67]
2.  A dockyard or shipyard.
Yard number
Each shipyard typically numbers the ships that it has built in consecutive order. One use is to identify the ship before a name has been chosen.
Yard tackle
Tackles to raise boats [67]
The very end of a yard. Often mistaken for a "yard", which refers to the entire spar, as in to hang "from the yardarm" and the sun being "over the yardarm" (late enough to have a drink).
Acknowledgement of an order, or agreement. Also aye, aye.
A vessel's rotational motion about the vertical axis, causing the fore and aft ends to swing from side to side repetitively.
A fore-and-aft rigged sailing vessel with two masts, main and mizzen, the mizzen stepped abaft the rudder post.
Yawl boat
A rowboat on davits at the stern of the boat.

See also[edit]


  1. ^ However, "to turn turtle" means putting a turtle on its back by grabbing it by the flipper, and conversely is used to refer to a vessel that has turned upside down, or which has cast off its crew. Smyth, W. H.; Belcher, E. (1867). The sailor's word-book: An alphabetical digest of nautical terms, including some more especially military and scientific ... as well as archaisms of early voyagers, etc. London: Blackie and Son. pp. 702–703. 


  2. ^ "Naval Slang Dictionary" (PDF). Retrieved February 19, 2014. 
  3. ^ a b Hope, Ranger (2007). "A Seaman's Dictionary" (PDF). Hope Ranger. Retrieved February 15, 2014. 
  4. ^ Layton, C.W.T.; Clissold, Peter; Miller, A.G.W. (1994). "Dictionary of Nautical Words and Terms: 8000 Definitions in Navigation, Seamanship, Rigging, Meteorology, Astronomy, Naval Architecture, Average, Ship Economics, Hydrography, Cargo Stowage, Marine Engineering, Ice Terminology, Buoyage, Yachting, etc" (PDF) (Revised Fourth ed.). Glasgow: Brown, Son & Ferguson, Ltd., Nautical publishers. Archived from the original (PDF) on February 27, 2014. Retrieved February 23, 2014. 
  5. ^ Hydrographic Dictionary: "Abeam", International Hydrographic Organization.
  6. ^ a b A naval encyclopædia: comprising a dictionary of nautical words and phrases; biographical notices, and records of naval officers; special articles of naval art and science. Philadelphia: LR Hamersly & Co. 1881. Retrieved January 23, 2014.  at Internet Archive
  7. ^ MacKenzie, Mike (2005–2012). "Home page". Sea Talk Nautical Dictionary: the Dictionary of English Nautical Language. Retrieved January 15, 2014. 
  8. ^ a b c Covey-Crump, Commander A., R.N. (2000). "1775 Naval Terms and Slang". H.M.S. Richmond. Retrieved February 19, 2014. 
  9. ^ "Module 1 – Basics of Shipboard life". Ready-for-Sea Modular Course & Handbook. Federation of American Scientists. Retrieved 19 July 2015. 
  10. ^ "World War II Naval Dictionary". USS Abbot (DD-629). Retrieved February 19, 2014. 
  11. ^ Art of Rigging 1848, p. 2.
  12. ^ Bathe, Basil W.; Villiers, Alan (March 1978). The Visual Encyclopedia of Nautical Terms Under Sail. New York Crown Publishers Inc. ISBN 0517533170.  ISBN 978-0517533178
  13. ^ Martin, Gary. "'Let the cat out of the bag' – the meaning and origin of this phrase". Phrasefinder. 
  14. ^ "CBDR". Free Dictionary. Retrieved 2011-06-24. 
  15. ^ Oxford English Dictionary, s.v. "corinthian".
  16. ^ "corinthian". 
  17. ^ Benham 1986, p. 186.
  18. ^
  19. ^ Jeans, Peter D (1998). Ship to Shore. Oxford, England: ABC-Clio. ISBN 1-85109-321-4. 
  20. ^ Luce, Commodore S. B., US Navy; Ward, Aaron, Lieutenant, US Navy; Seabury, S., Lieutenant, US Navy (illustrator) (1997–2007) [1834]. Text-Book of Seamanship: The Equipping and Handling of Vessels Under Sail or Steam for the Use of the United States Naval Academy (Revised and enlarged ed.). New York: Van Nostrand Company for U.S. Naval Academy/Smith & McDougal, Electrotypers/ 
  21. ^ "Deadwood". Retrieved March 12, 2014. 
  22. ^ Glickman, Todd S., Editor (June 2000). Doldrums (electronic). Meteorology Glossary (2nd ed.). Cambridge, Massachusetts: American Meteorological Society. Retrieved March 10, 2014. 
  23. ^ Encarta: World English Dictionary. New York: St. Martin's Press, Microsoft. 1999. p. 533.  Missing or empty |title= (help)
  24. ^ Arhoolie Records > The Foo Foo Band Accessed 11 March 2014.
  25. ^ Lubbock, B. (1921): The Colonial Clippers Digital copy, Internet Archive, 2007. pp. 158–59.
  26. ^ Melville, Herman (1851). "53". Moby-Dick; or, The Whale. Harper and Brothers. 
  27. ^ Carr 1951, p. 96.
  28. ^ a b Carr 1951, p. 55.
  29. ^ Blackburn, Graham (November 21, 2002). The Illustrated Encyclopaedia of Ships and Boats (Hardcover). London: I.B.Tauris. p. 263. ISBN 1860648398. ISBN 978-1860648397. 
  30. ^ Carr 1951, p. 60.
  31. ^ Smyth's sailors' wordbook, 1867
  32. ^ Carr 1951, p. 59.
  33. ^ Admiralty Manual of Seamanship. I. London: HMSO. 1964. 
  34. ^ a b Smyth, William Henry (1867). The Sailor's Word-Book. Glasgow: Blackie & Co. 
  35. ^ "pendant". Oxford English Dictionary (3rd ed.). Oxford University Press. September 2005.  (Subscription or UK public library membership required.)
  36. ^ Knight, Edward H. (1884). Knight's American mechanical dictionary. 3. Boston: Houghton, Mifflin, and Co. p. 1904. OCLC 5960856. 
  37. ^ a b c d Art of Rigging 1848, p. 24.
  38. ^ a b c Art of Rigging 1848, p. 25.
  39. ^ Art of Rigging 1848, p. 26.
  40. ^ Webster's New World College Dictionary, Fifth Edition, copyright 2014 by Houghton Mifflin Harcourt Publishing.
  41. ^ Fraser, Russell. A Machine That Would Go of Itself: The Constitution in American Culture, p. 43 (Routledge 2017).
  42. ^ "Shift Colors". Retrieved 2011-06-24. 
  43. ^ Leonard George Carr Laughton; Roger Charles Anderson; William Gordon Perrin (1958). The Mariner's Mirror. Society for Nautical Research. 
  44. ^ "shift, v. 13.b.". OED Online. Retrieved 2009-04-29. 
  45. ^ a b c Benham 1986, p. 187.
  46. ^ a b Art of Rigging 1848, p. 30.
  47. ^ "Snotty definition and meaning - Collins English Dictionary". 
  48. ^ Mayne, Richard (2000). The Language of Sailing (Print). Chicago, Ill: Fitzroy Dearborn; Taylor & Francis. p. 282. ISBN 1-57958-278-8. 
  49. ^ Carr 1951, p. 63.
  50. ^ "Shiprigging - The Way a VOC ship was rigged". 
  51. ^ Art of Rigging 1848, p. 31.
  52. ^ a b Art of Rigging 1848, p. 32.
  53. ^ Carr 1951, p. 71.
  54. ^ Art of Rigging 1848, p. 33.
  55. ^ Art of Rigging 1848, p. 34.
  56. ^ Carr 1951, p. 37.
  57. ^ a b c d Art of Rigging 1848, p. 35.
  58. ^ Keegan, John (1989). The Price of Admiralty. New York: Viking. p. 281. ISBN 0-670-81416-4. 
  59. ^ Friedman, Norman (1985). U.S. Battleships: An Illustrated Design History. Annapolis, Maryland: Naval Institute Press. p. 173. ISBN 0-87021-715-1. 
  60. ^ a b c d Art of Rigging 1848, p. 36.
  61. ^ "deck, turtle nautical: A term applied to a weather deck that is rounded over from the shell of the ship so that it has a shape similar to the back of a turtle. Used on ships of the whaleback type and on the forward weather deck of torpedo boats." "World War II Naval Dictionary". USS Abbot (DD-629). Retrieved February 19, 2014. 
  62. ^ "turtle, turn turtle (of a boat) to turn over completely while sailing". Oxford Advanced Learner's Dictionary. Oxford University Press. 2013. Retrieved 3 December 2013. 
  63. ^ "Definition of turtle in English "turn turtle" (chiefly of a boat) turn upside down: ". Oxford Dictionaries. Oxford University Press. 2013. Retrieved 3 December 2013. 
  64. ^ "waist definition". Retrieved 2008-12-11. 
  65. ^ a b c d e f Art of Rigging 1848, p. 37.
  66. ^ Moby Dick, Melville H
  67. ^ a b c Art of Rigging 1848, p. 38.


  • Benham, Hervey; Finch, Roger; Kershaw, Philip (1986). Down tops'l : the story of the East Coast sailing-barges (3rd ed.). London: Harrap. ISBN 0245544879. 
  • Biddlecombe, George (1990). Pentecost, Ernest H., ed. The art of rigging : containing an explanation of terms and phrases and the progressive method of rigging expressly adapted for sailing ships. New York: Dover Publications. ISBN 0486263436. 
  • Renouf, David (2017). "Thames Sailing Barges - Glossary". Archived from the original on 2016-10-23. 

Further reading[edit]

External links[edit]