A dual drive system for providing motive power to a watercraft has a frame configured for connecting to the watercraft and a drive assembly connected to the frame. The drive assembly has a manual drive mechanism configured for receiving mechanical input from a user, a motor drive mechanism configured for receiving mechanical input from a motor, a driveshaft having a first end in selective engagement with one of the manual drive mechanism and the motor drive mechanism and a second end in engagement with a propeller, and a drive selector for selectively engaging the manual drive mechanism or the motor drive mechanism with the driveshaft based on a position of the drive selector between first and second positions. In the first position, the drive selector engages the manual drive mechanism with a driveshaft. In the second position, the drive selector engages the motor drive mechanism with the driveshaft.