An underwater scooter is provided with an engine enclosed in a watertight vessel and an electric motor enclosed in the watertight vessel and connected to the output shaft of the engine, and a propeller disposed upon a main frame and connected to the output shaft of the motor to be driven and turned by at least one of the engine and the motor so as to propel the scooter. In other words, the scooter is a hybrid type having the engine and electric motor as the drive power of the propeller. With this, the operator can easily re-start, once stopped on the surface of the water or underwater. Moreover, since the propeller can be driven even by the engine, a distance of travel is elongated with less increased weight, when compared to the case that the propeller is driven solely by the engine.