Patent ID: 7481687

Claim:
A propulsion system for a small water craft, comprising: a. a housing having an interior space for receiving an impeller, said impeller comprising a tubular body and two or more groups of blades, each group of blades comprising a plurality of blades extending from the inside of said tubular body towards the center of said tubular body without meeting at the center of said tubular body and angled to push water from the inlet to the outlet of the impeller housing when said impeller is powered to rotate; b. the linear spacing of said blades along the axis of said impeller body being progressively closer each other as the blades approach the impeller outlet and the circumferential location of said blades staggered such that their locations within said impeller body, when viewed in toto, approximate a spiral comprising a plurality of individual blades, said spiral getting progressively tighter towards the outlet; c. said impeller body supported on sealed bearings thereby allowing the impeller to rotate in said housing while preventing water from entering said housing; d. said impeller powered by a ring gear, said ring gear attached to the exterior of said impeller body; said ring gear driven by a drive shaft, said drive shaft comprising first and second ends, said first end comprising a bevel or spiral bevel gear that intermeshes with said ring gear and said second end comprising a slip clutch, wherein said slip clutch is connected to a power source when said power source is turned on and the rotation of said impeller is not impeded and is not connected to said power source when the rotation of said impeller is impeded.