Abstract: The watercraft has a hull with an upwardly curved (concave) bottom and side keels extending downwardly for the full longitudinal length of the watercraft spaced laterally from each other and on opposite sides of the watercraft. Forward and rearward hydrofoils are arranged on either side of the hull and project from the keels for swivelling about generally vertical axes angled downwardly and outwardly. The hydrofoils on one side are adjustable independently of the hydrofoils on the other side for adjusting the angle of attack of the hydrofoil lifting surfaces that are curved outwardly to be generally horizontal. Fixed hydrofoils between and respectively longitudinally aligned with the adjustable hydrofoils are attached to the hull. Propellers that swivel about axes extending downwardly and outwardly at approximately 15.degree. to the vertical are respectively mounted for swivelling movement along with attached rudders for steering.