A Bruce foil is a variant of the leeboard, an arrangement to provide a sailing boat with resistance to sideways movement so that the sails will produce nearly forward movement under a variety of apparent wind directions.
A Bruce foil is a variant of the leeboard invented by Edmond Bruce in the early 1960s. A leeboard is one of many arrangements to provide a sailing boat with resistance to sideways movement so that the sails will produce nearly forward movement under a variety of apparent wind directions.