What does centreboard mean?
A centreboard is a movable board or plate set in a slot along the centreline of a small sailing boat's hull, typically pivoting so it can be raised or lowered from inside the boat. When sailing upwind, the crew lowers the centreboard into the water, where it acts as a lateral foil, resisting the sideways push of the wind and allowing the boat to make progress toward its destination. When the wind frees off, or when the boat must cross shallows or be run onto a beach, the board can be retracted, reducing draft dramatically. This simple mechanism gives dinghies and other small craft a versatility that fixed-keel boats lack, combining decent windward performance with access to shallow creeks and easy launching. The word follows British spelling conventions, with centerboard as its American counterpart, and daggerboard naming a similar but non-pivoting fitting.
nounA retractable board or plate pivoted in a slot in the bottom of a small sailing boat, lowered into the water to prevent sideways drift and raised to allow the boat to sail in shallow water.
- A movable, usually pivoting board fitted through a slot in the keel or hull of a small sailing vessel, which can be lowered to resist leeway and retracted for shallow water or beaching.
"The dinghy's centreboard swung up with a clang as she ran aground on the sandbar."
"Before entering the narrow creek, the crew raised the centreboard so the boat could float over the shallows."
"A well-shaped centreboard makes all the difference when beating to windward in a light dinghy."
Regular plural; used when discussing multiple boats or comparing designs.
"Modern racing classes vary widely in the shape and area of their centreboards."
A centreboard lets one small boat have the best of both worlds: deep-keel stability upwind and a shoal draft that glides right onto the beach.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of centreboard
Centreboard is a straightforward compound of 'centre' and 'board', coined in nineteenth-century nautical English to describe a board mounted on a boat's centreline. The element 'centre' ultimately traces back to Latin 'centrum', meaning the point around which something turns, itself borrowed from Greek 'kentron', a sharp point or pivot. Related English words sharing this classical root include 'central', 'concentrate' and 'eccentric'. The device itself became widespread with the rise of small recreational sailing craft during the nineteenth century.
How centreboard is actually used
Centreboard is the standard British spelling, while centerboard predominates in American English; both refer to the same fitting. The term belongs chiefly to the vocabulary of dinghy sailing and small-craft design. Daggerboard denotes a related but distinct device that slides vertically rather than pivoting, and the two are not interchangeable in technical usage.
Easily confused with centreboard
Centerboard is simply the American spelling of the same word; centreboard is the British spelling — they denote identical objects.
A keel is a fixed, permanent structural member along the hull's bottom, whereas a centreboard is a movable plate that can be raised and lowered.