Schmidt Outfitters - The Best in Fly-Fishing

Basic Fly Lines

by Schmidt Outfitters Staff

The Fly Line

Unlike most forms of fishing where the reel and rod are the foundation of the tackle, a discussion of fly fishing tackle begins with the fly line. Flies have virtually no weight and are of no help to the caster. In fact, because of their air resistance, some flies make casting more difficult than with no fly at all. For weight and help with casting, the fly fisher looks to the line.

Fly lines are available in what may appear to be many thousands of combinations of taper, weight, color, and lengths. Even experienced fly anglers are boggled by the availability of choice. The primary considerations in selecting and using the right fly line include the following categories of specifications: line weight, line taper, and line type including floating, sinking, and sink-tip lines. Selecting correctly from these categories will help you set up your entire fly fishing rig accurately.

Line Weights

Fly lines are designed to be the casting weight in fly fishing tackle. Unlike other types of fishing, the fly caster’s lure, the fly, has no weight to be cast. The heavier, thicker fly line gives the fly fisher a weight to cast. Within the range of fish that can be caught on a fly--everything from a bluegill of several ounces to salmon and steelhead of 20 pounds to saltwater species of several hundred pounds--a range of ‘weights’ of fly lines are designed to be successful for each type of fishing. In general, the weight of a fly line is increased for a heavier species of fish, which often requires a larger fly.

Fly fishing tackle manufacturers weigh the first 30 feet of the various thickness of line they produce for the different game fish in the world. Based on a set of weights in grams, the lines were designated as an X-weight line. Rods are designed to most efficiently cast a fly line with the same weight designation. For example, a 5-weight line and a 5-weight rod are considered by manufacturers to be ‘matched’ for the best usage by most fly casters.

Currently, lines are produced in weights from 0 through 15. A 0-weight is the lightest and a 15-weight is the thickest and/or heaviest fly line. With the correct rod, a 0-weight might be used for small brook trout or panfish, while the heavier line and stiffer rod of the 15-weight might be used for big saltwater species, such as billfish or tuna.

Type of Game Fish Suggested Line/Rod Weight

  • Bluegill/panfish: 2 or 3
  • Trout: 4, 5, 6
  • Smallmouth bass: 5, 6, 7
  • Largemouth bass: 6, 7, 8
  • Pike and Muskie: 7, 8, 9
  • Steelhead and Salmon: 7, 8, 9, 10
  • Bonefish: 8 or 9
  • Tarpon: 11 or 12

Line Taper

The decision to designate line weights for both lines and rods has been very successful. The next evolutionary step was to designate tapers on the various line weights. The taper idea was in response to a set of problems. For example, a caster using an 8-weight fly line for bass faces an entirely different set of circumstances than a steelhead angler with the same weight rod. A bass bug is often a large fly made of deer hair. Bass bugs are very wind-resistant flies that are difficult to cast. To cast this fly more easily, an angler might go to the next heavier rod, a 9-weight, but this could result in hooking and landing fish on a rod that’s so stiff that the ‘sport’ is taken out of the fishing.

The answer was to taper the line. By moving more of the line’s weight toward the front (most often used) section of the fly line, the effective, usable weight of the line is increased. The line’s weight remains the same, so it is balanced for the 8-weight rod (in this case), but moving the weight forward on the line gives the bass bug caster an advantage when casting bigger, more air-resistant flies. Voila, the weight-forward fly line was born.

Conversely, some trout fishers noticed that the end of the fly line striking the water spooked fish in slow, clear waters such as spring creeks. “Never mind better casting technique,” they said, “give us a fly line that lands more lightly on the water.” So the double-taper fly line was designated. It’s heavier in the middle and tapers toward each of its ends. An unexpected value was that by reversing the line on the reel, the fly fisher gets the usability and life of two fly lines.

Sinking Fly Lines

The basic lines had various tapers, but all floated. Subsurface presentation of certain nymphs and streamer flies required the addition of weight to either line or leader. Consequently, a number of styles of sinking lines were developed. In general, sinking fly lines can be divided into full sinking and sink tip.

Full Sinking

The full sinking fly line is weighted from one end to the other. This kind of line is used most often for presentation of nymphs or streamers in deeper water or faster river currents. With the fully weighted line, a fly tends to stay deeper in the water column. Within the category of full sinking, several subcategories exist. These categories are arranged around the actual weight, and thus the sink rates, of the lines. Examples include slow sink, which has a sink rate of about 1 to 3 inches per second; medium sink, which sinks at a rate of about 3 to 4 inches per second; and fast sink, which is about 5 to 7 inches per second. Depending on the manufacturer, other labels might include a super fast sink or a uniform sink line.

Sink Tip

The sink tip fly line is a combination line: the front part of the line sinks and the rest of the line floats. Depending on the manufacturer and the model, a sink tip line in general has a sinking section of 8 to 24 feet, while the rest of the line floats. Manufacturers give the two sections different colors to assist the angler in handling the line. Some sink tips are rated by their weight, such as a 200-grain, 24-foot tip, while others are rated by categories like their full sinking counterparts. Categories include slow sink, medium sink, and others.

Another type of sink tip is the shooting head. This is a removable length of weighted line that is attached to a lighter fly line, and sometimes just heavy monofilament. The shooting heads come in a variety of weights and lets anglers adjust the sinking weight of the line to match water and fishing situations.