Patent ID: 7427221

Claim:
A water craft adapted to be propelled comprising a water pumping arrangement including a sheath carried by the water craft, the sheath including a propeller adapted to be turned, the sheath, water craft and propeller being arranged for causing the propeller while turning and while the water craft is moving forward in a body of water to (a) suck water from the body of water into the sheath interior via at least one opening in the sheath, (b) force the sucked water upwardly and (c) force the upwardly forced water through another opening in the sheath below the surface of the body of the water for causing the water forced through the another opening to (i) have speed greater than the speed of the water sucked into the sheath and (ii) cause air bubbles to be induced in the water above the another opening, and another opening arranged to be maintained during steady state operation of the propellers about four to six inches below the water surface while the water craft is moving forward in the body of water.