An error in a yacht's magnetic compass which can be caused when she heels. Most ships' compasses are stabilized and corrected with small magnets to prevent errors when the vessel is rolling or takes a slight list, but a sailing yacht's compass is more liable to become affected when the yacht heels sharply. The cause is usually the shifting positions of adjacent ferrous metal objects in relation to the compass card, which remains level to the horizon by means of its gimbals. See also swing a ship, to.
Subjects: Maritime History.