Ship propulsion system

A ship propulsion system comprising:

• a plurality of ship propulsion devices provided in a ship and configured to propel the ship;
• a control device configured to control the plurality of ship propulsion devices;
• a plurality of authentication devices that respectively stores different authentication codes;
• and
• a communication device storing one of the authentication codes respectively stored in the plurality of authentication devices and configured to transmit the one of the authentication codes to the plurality of authentication devices, wherein
• the plurality of ship propulsion devices include three or more ship propulsion devices,
• the plurality of ship propulsion devices are disposed in a manner of being bilaterally symmetrical about a center of the ship in a left-right direction,
• each of the plurality of authentication devices corresponds to one or more ship propulsion devices among the plurality of ship propulsion devices,
• two or more authentication devices among the plurality of authentication devices do not simultaneously correspond to one ship propulsion device of the plurality of ship propulsion devices,
• each of the plurality of authentication devices is configured to operate as a master authentication device when an authentication code transmitted from the communication device matches an authentication code stored in the plurality of authentication devices,
• the master authentication device is configured:
• to recognize whether a malfunction occurs in each of the plurality of authentication devices;
• and to select a ship propulsion device disposed in a manner of being bilaterally symmetrical about the center of the ship in the left-right direction from ship propulsion devices corresponding to an authentication device in which no malfunction occurs among the plurality of authentication devices, and
• the control device is configured to bring the ship propulsion device selected by the master authentication device into an operable state.