A cutter is typically a small, but in some cases a medium-sized, watercraft designed for speed rather than for capacity. Traditionally a cutter sailing vessel is a small single-masted boat, fore-and-aft rigged, with two or more headsails and often a bowsprit. The cutter's mast may be set farther back than on a sloop.
In modern usage, a cutter can be either a small- or medium-sized vessel whose occupants exercise official authority. Examples are harbor pilots' cutters and cutters of the U.S. Coast Guard or UK Border Force.
Cutters can also be a small boat serving a larger one to ferry passengers or light stores between larger boats and the shore. This type of cutter may be powered by oars, sails or a motor.
The cutter is one of several types of sailboats. Traditionally the sloop rig was a rig with a single mast located forward of 70% of the length of the sailplan. In this traditional definition a sloop could have multiple jibs on a fixed bowsprit.
Cutters had a rig with a single mast more centrally located, which could vary from 50% to 70% of the length of the sailplan, with multiple headsails and a running bowsprit. A mast located aft of 50% would be considered a mast aft rig.
Somewhere in the 1950s or 1960s there was a shift in these definitions such that a sloop only flew one headsail and a cutter had multiple headsails and mast position became irrelevant. In this modern idiom, a cutter is a sailing vessel with more than one head sail and one mast. Cutters carry a staysail directly in front of the mast, set from the forestay. A traditional vessel would also normally have a bowsprit to carry one or more jibs from its end via jibstay(s) on travelers (to preserve the ability to reef the bowsprit). In modern vessels the jib may be set from a permanent stay fixed to the end of a fixed (non-reeving) bowsprit, or directly to the stem fitting of the bow itself. In these cases, that may be referred to as the forestay, and the inner one, which will be less permanent in terms of keeping the mast up, may be called the stays'l stay. A sloop carries only one head sail, called either the foresail or jib..