1) Centerboard 2) Centreboard 3) Drop keel 4) Sliding keel 1) Hull 2) Keel 
A daggerboard is a retractable centreboard used by various sailing craft. While other types of centreboard may pivot to retract, a daggerboard slides in a casing. The shape of the daggerboard converts the forward motion into a windward lift, countering the leeward push of the sail. The theoretical centre of lateral resistance is on the trailing ed...
A type of light centerboard that is lifted vertically; often in pairs, with the leeward one lowered when beating.
A type of light centerboard that is lifted vertically; often in pairs, with the leeward one lowered when beating.
A narrow blade shaped centreboard which is raised vertically.
Lifting keel that moves up and down through its case or trunk instead of pivoting like a centreboard. A Mirror dinghy uses a daggerboard arrangement. 
another term for a center board
A blade shaped centerboard that is lifted out of a case when raised. Usually only suitable for small boats. 
A board dropped vertically through the hull to prevent leeway. May be completely removed for beaching or for sailing downwind.
A type of centerboard that is removed vertically.
[n] - a removable centerboard on a small sailboat that can be lowered into the water to serve as a keel
noun a removable centerboard on a small sailboat that can be lowered into the water to serve as a keel
An adjustable fin primarily used to stop the boat moving sideways through the water. Also called centreboard.