Patent ID: 7100867

Claim:
In a lifting foil the combination of (a) A lower course having a lower starboard margin and a lower port margin, said lower course extending sideward between said lower starboard margin and said lower port margin and being responsive to fluid flow in a direction −X, for generating a first fluid reaction force having a first lifting component in a direction −Z. (b) An upper course having an upper starboard margin and an upper port margin, said upper course being positioned above said lower course and extending sideward between said upper starboard margin and said upper port margin for generating a second fluid reaction force having a second lifting component in said direction, −Z, parallel and additive to said first reaction force. (c) A starboard flow guide extending vertically between said lower starboard margin and said upper starboard margin, having a progressively adjusted camber for suppressing spanwise fluid flow in a direction +Y, perpendicular to −X and −Z, and (d) A port flow guide extending vertically between said lower port margin and said upper port margin, having a progressively adjusted camber for suppressing spanwise fluid flow in a direction −Y, opposite to +Y.