 There are generally three types of boat, inland (used on lakes and rivers), inshore (used in coastal waters) and offshore (into deeper waters and further out to sea).A rescue lifeboat is a boat designed with specialised features for searching for and rescuing people in peril at sea or in estuaries.Where practicable, lifeboats will usually perform minor salvage and towing operations to assist mariners in distress and prevent navigational hazards.