Centreboard

A centreboard (often called a lifting foil in a modern racing dinghy) is used to provide lift to counter the lateral force from the sails. This is required for sailboats to move in directions other than downwind, since the force of the sail is never closer than 45 degrees to the apparent wind. Since most sailboats are symmetric along their axis of motion, when sailing upright, the lateral force can come from either side, which means that centreboards must use symmetric foil shapes so they will operate with equal efficiency on either tack. The more a yacht heels the more asymmetric its hull shape becomes. The centerboard, daggerboard or bilgeboard can be used as a recovery platform upon which to stand, providing increased leverage, in the event the dinghy overturns via a capsize or turtle.