A watercraft propulsion system comprising: a bow thruster at a bow of a hull to generate a lateral propulsive force; at least two propulsion devices on a stern of the hull each having a variable steering angle; a translation/bow turning operator to be operated by a user to apply a translation command to translate the hull and a bow turning command to turn the bow of the hull; and a controller configured or programmed to control the bow thruster and the at least two propulsion devices; wherein the controller is configured or programmed to, in a translation watercraft maneuvering mode, drive the bow thruster, and drive one of the at least two propulsion devices forward and drive another of the at least two propulsion devices in reverse while controlling the steering angles of the at least two propulsion devices so that propulsive force action lines (71s, 71p) of the at least two propulsion devices cross each other in the hull to translate the hull in response to an operation of the translation/bow turning operator; and characterized in that the controller includes a calibration mode in which calibration is performed for the translation watercraft maneuvering mode; the controller is configured or programmed to control the bow thruster and the at least two propulsion devices according to the translation command and the bow turning command applied by the translation/bow turning operator in the calibration mode; the controller is configured or programmed to increase an output of the bow thruster when the bow turning command is a bow turning promoting command that commands bow turning in a direction indicated by the translation command, and to reduce absolute values of the steering angles of the at least two propulsion devices when the bow turning promoting command is still applied even after the output of the bow thruster reaches an upper limit; and the controller is configured or programmed to increase the absolute values of the steering angles of the at least two propulsion devices when the bow turning command is a bow turning reduction command that commands bow turning in a direction opposite to the direction indicated by the translation command, and to reduce the output of the bow thruster when the bow turning reduction command is still applied even after the absolute values of the steering angles reach an upper limit. a bow thruster at a bow of a hull to generate a lateral propulsive force; at least two propulsion devices on a stern of the hull each having a variable steering angle; a translation/bow turning operator to be operated by a user to apply a translation command to translate the hull and a bow turning command to turn the bow of the hull; and a controller configured or programmed to control the bow thruster and the at least two propulsion devices; wherein the controller is configured or programmed to, in a translation watercraft maneuvering mode, drive the bow thruster, and drive one of the at least two propulsion devices forward and drive another of the at least two propulsion devices in reverse while controlling the steering angles of the at least two propulsion devices so that propulsive force action lines (71s, 71p) of the at least two propulsion devices cross each other in the hull to translate the hull in response to an operation of the translation/bow turning operator; and characterized in that the controller includes a calibration mode in which calibration is performed for the translation watercraft maneuvering mode; the controller is configured or programmed to control the bow thruster and the at least two propulsion devices according to the translation command and the bow turning command applied by the translation/bow turning operator in the calibration mode; the controller is configured or programmed to increase an output of the bow thruster when the bow turning command is a bow turning promoting command that commands bow turning in a direction indicated by the translation command, and to reduce absolute values of the steering angles of the at least two propulsion devices when the bow turning promoting command is still applied even after the output of the bow thruster reaches an upper limit; and the controller is configured or programmed to increase the absolute values of the steering angles of the at least two propulsion devices when the bow turning command is a bow turning reduction command that commands bow turning in a direction opposite to the direction indicated by the translation command, and to reduce the output of the bow thruster when the bow turning reduction command is still applied even after the absolute values of the steering angles reach an upper limit.