Scuba tank compressed air can now power a dual piston compound motor driving dual water thrusters of a steady pulling underwater propulsion vehicle. Motor exhaust provides diver breathing air through a demand regulator. Motor efficiency allows continual, powerful diver thrust without curtailing normal tank dive time. Lightweight vehicle can be strapped to the scuba tank for "hands free" operation or "diver held" for driving through the water. Diver controls off/on/variable speed with a simple throttle control. Propeller or battery is not required.