Fin keel

1.

(Naut.) A projection downward from the keel of a yacht, resembling in shape the fin of a fish, though often with a cigar-shaped bulb of lead at the bottom, and generally made of metal. Its use is to ballast the boat and also to enable her to sail close to the wind and to make the least possible leeway by offering great resistance to lateral motion through the water.

Thesaurus

Noun

1.

fin keel - a metal plate projecting from the keel of a shallow vessel to give it greater lateral stability centerboard, centreboard, drop keel, sliding keel - a retractable fin keel used on sailboats to prevent drifting to leeward keel - one of the main longitudinal beams (or plates) of the hull of a vessel; can extend vertically into the water to provide lateral stability plate - a sheet of metal or wood or glass or plastic