Abstract: An asymmetrically arranged hydrofoil and propeller system is disclosed for improving the speed and lift of watercraft such as amphibious vehicles. When the vehicle is propelled through water by propellers, a downwash of water from the upper surface of the asymmetrically arranged hydrofoils is intercepted by upwardly moving propeller blades which improve the speed, lift and efficiency of the watercraft.

Abstract: A power driven tracked amphibious vehicle is disclosed for moving troops from ships to shore at speeds in excess of 25 miles per hour. The vehicle includes a pair of hydrofoil assemblies each pivoted to the vehicle for movement between an operative water mode position with the hydrofoils and inline water jet propulsion units submerged in water for propelling the vehicle while in water, and a land mode with the hydrofoils and water jet propulsion units raised above the tracks for propelling the vehicle on land. When in the water mode the tracks are raised a short distance, and the track covers and bow flaps are positioned below the tracks for minimizing drag on the vehicle.

Abstract: A pair of integrated water propulsion and hydrofoil systems capable of moving through water at speeds of at least 20 miles per hour are disclosed, each hydrofoil system having a hydrofoil and a mounting leg removably secured to a water propulsion system. The mounting legs are supported on opposite sides of the watercraft for moving the hydrofoils between a water mode and a land mode. The water propulsion system may be an inline water jet, and the hydrofoils may be formed from interconnected lightweight hollow beams with power operated flaps on the trailing portions of the hydrofoils for adding more lift when moving at slow speeds through water. The watercraft may be a military amphibious vehicle weighing about 30 tons.

Abstract: An improved watercraft and propulsion system is disclosed for moving a watercraft such as an amphibious vehicle or a speed boat from 0 velocity to speeds in excess of 20 miles per hour. Each watercraft includes water propulsion systems which are preferably pivotally mounted on or near the rear end of the watercraft for pivotal movement between a transversely aligned stowed position above the vehicle and an operative position within the watercraft and below the vehicle. Hydrofoils may be connected to the water propulsion system, and bow or transom flaps plus the planing hull of the vehicle aids in providing adequate lift when in the water.