An underwater scooter includes a watertight vessel enclosing an engine disposed in the fore part of a cylindrically shaped main frame, a propeller disposed in the aft area, and a driveshaft passes through the interior of the main frame and transmits the output of the engine to the propeller. An operator rides upon air tanks disposed between the engine and the propeller on the main frame, so the burden on the operator can be reduced in comparison to that of conventional types that tow the operator. In addition, the propeller is disposed aft of the operator and also the exhaust gas from the engine is exhausted aft of the operator, so there is no risk of either the jet of water ejected by the propeller or the exhaust gas reducing the field of view or causing articles (goggles, etc.) worn by the operator to come off.