Glossary · Keels, foils & rudders
Daggerboard
Also called: Dérive, dérives droites, straight daggerboards, dérive asymétrique
A retractable vertical fin that stops the boat drifting sideways, without lifting it.
A daggerboard slides in a case through the hull. Down, it provides lateral resistance; raised, it removes its drag downwind. On a canting-keel monohull, two daggerboards (one per side) make up for the tilted keel.
Before foils, IMOCAs and multihulls used straight daggerboards; foils were born by curving these boards so that they produce lift.
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