What does centerboard mean?
A centerboard is a movable board—typically of wood, fiberglass, or metal—that extends downward through a slot (called the centerboard trunk) in the bottom of a sailboat's hull. Its purpose is to provide lateral resistance: without it, wind pushing on the sails would drive the boat sideways rather than forward. Because the board pivots on a hinge near its forward end, it can be raised into the trunk when sailing downwind or entering shallow water, allowing small craft to float where fixed-keel boats cannot. Centerboards are especially common on dinghies, daysailors, and other small vessels launched from beaches or trailers. The design is closely associated with nineteenth-century American boatbuilding, and its practicality helped popularize recreational sailing in shallow coastal waters. The word is technical and chiefly nautical, spelled 'centreboard' in British English, and is best known to sailors, boatbuilders, and enthusiasts of small-craft design.
nounA movable board or plate of wood or metal that slides down through a slot in the bottom of a sailboat's hull to reduce leeway and improve stability, and can be raised when not needed.
- A pivoting retractable board fitted through a slot in a small sailboat's hull to provide lateral resistance against the wind.
"The sailor lowered the centerboard before turning upwind to keep the dinghy from sliding sideways."
"Before tacking upriver, she dropped the centerboard so the hull would grip the water instead of skidding sideways."
"The trailerable sloop's centerboard swung up into its trunk whenever it ran aground on the sandbar."
Regular plural; used mainly when discussing different boats or designs.
"Most modern trailer-sailers use swing-up centerboards for beach launching."
The humble hinged board beneath millions of small sailboats is an American invention of the early 1800s that helped make shallow coastal waters and rivers accessible to sailors everywhere.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of centerboard
Centerboard is a compound of 'center' and 'board', formed in English during the early nineteenth century to name a device that emerged in American small-craft design around that time. The element 'center' derives ultimately from Greek 'kentron', meaning a sharp point or pivot point, which passed into Latin as 'centrum' before entering English via French. The same Greek-Latin root underlies related English words such as 'eccentric', 'concentric', and 'centrifugal'. In British usage the compound appears as 'centreboard', reflecting the British spelling of its first element.
How centerboard is actually used
A chiefly nautical, technical term used by sailors, boat designers, and marine writers; in British English it is more commonly spelled 'centreboard'. It is neutral in register but rarely encountered outside boating contexts.
Easily confused with centerboard
A daggerboard lifts straight up out of its slot vertically, while a centerboard pivots on a hinge at the front of its trunk.