Watercraft propulsion system, and watercraft

A watercraft propulsion system comprising:

• a main propulsion device attachable to a hull;
• an auxiliary propulsion device attachable to the hull and having a lower rated output than the main propulsion device;
• a lift to move up and down a propeller of the auxiliary propulsion device between an underwater position and an above-water position;
• and
• a controller including a plurality of control modes including a combined use mode in which a propulsive force generated by the main propulsion device and a propulsive force generated by the auxiliary propulsion device are used in combination, and configured or programmed to restrict the main propulsion device and the auxiliary propulsion device from being driven according to the combined use mode when the propeller of the auxiliary propulsion device is in the above-water position;
• wherein
• the controller is configured or programmed to determine whether or not the propeller of the auxiliary propulsion device is in the above-water position in the combined use mode, and to restrict the main propulsion device and the auxiliary propulsion device from being driven if the propeller of the auxiliary propulsion device is in the above-water position.