Variable-pitch-propeller drive device and pitch-angle control method, and boat having same

Provided is a driving apparatus of a variable pitch propeller having blades, each of which has a pitch angle changed in a rotational direction of a propeller shaft, and a pitch adjuster for adjusting the pitch angle. The pitch adjuster includes blade actuating shafts that are connected to eccentric stubs coupled to lower ends of the blades and are disposed inside the propeller shaft so as to allow linear reciprocation and to push or pull the eccentric stubs, and a power converter that converts a rotating motion of the propeller shaft into a linearly reciprocating motion of the blade actuating shafts.