Abstract: A wind-propelled craft is disclosed which comprises a hull supporting a pair of unstayed masts arranged to pivot about an axis lying in approximately horizontal plane between a first position, in which one mast extends substantially vertically and the other extends generally at right-angles thereto away from the hull, and a second position, in which the relative configuration of the masts is reversed, each mast, in use, having a sail attached thereto or incorporating an aerofoil, whereby in use one sail or aerofoil can be trimmed to the wind to provide forward propulsion while the other sail or aerofoil simultaneously provides upward lift tending to counteract rolling or heeling force applied to the hull by wind impinging on the first sail or aerofoil. A steering control system is also described in which a steering link passes from a control point through the region of the pivot point of a mast to a rudder.

Abstract: A wind-propelled craft is disclosed which comprises a hull supporting a pair of unstayed masts arranged to pivot about an axis lying in an approximately horizontal plane between a first position, in which one mast extends substantially vertically and the other extends generally at right-angles thereto away from the hull, and a second position, in which the relative configuration of the masts is reversed, each mast, in use, having a sail attached thereto or incorporating an aerofoil, whereby in use one sail or aerofoil can be trimmed to the wind to provide forward propulsion while the other sail or aerofoil simultaneously provides upward lift tending to counteract rolling or heeling force applied to the hull by wind impinging on the first sail or aerofoil. A steering control system is also described in which a steering link passes from a control point through the region of the pivot point of a mast to a rudder.