Watercraft propulsion system and watercraft

A watercraft propulsion system comprising:

• a bow thruster at a bow of a hull to generate a propulsive force laterally of the hull;
• a propulsion device on the hull to generate a propulsive force anteroposteriorly of the hull;
• a steering to change a course of the hull;
• and
• a controller configured or programmed to control the bow thruster, the propulsion device, and the steering in response to a diagonal movement command to control an output of the bow thruster, the propulsive force generated by the propulsion device, and a steering angle of the steering;
• wherein
• the controller is configured or programmed to include a calibration mode in which a calibration value to be used to control the bow thruster, the propulsion device, and the steering according to the diagonal movement command is set, to increase the output of the bow thruster when a bow turning promotion command that causes bow turning in a movement direction indicated by the diagonal movement command is issued together with the diagonal movement command in the calibration mode, and to reduce the propulsive force of the propulsion device even if the output of the bow thruster reaches its upper limit when the bow turning promotion command is issued in the calibration mode.