Braking arrangements for inhibiting pedals of a pedal drive system for a watercraft from rotating when an assist drive train of the pedal drive system is activated are provided. Method of preventing pedals of a pedal drive system for a watercraft from rotating when using an assist mode are provided.

A centrifugal propulsion apparatus capable of forward and backward movement, and a ship having the same, the apparatus includes two impellers which are rotated by a power shaft, face each other, and are capable of jetting a fluid in opposite directions; and a power transmission unit provided between the power shaft and the two impellers so as to connect one impeller between the two impellers and the power shaft or connect the other impeller and the power shaft according to a rotational direction of the power shaft.