Marine propulsion system and marine vessel

A marine vessel comprising:

• a hull;
• and
• a marine propulsion system provided on or in the hull;
• wherein
• the marine propulsion system includes:
• a main propulsion device attached to a stern of the hull, including an engine to drive a main thruster to generate a first thrust, and operable to rotate in a right-left direction to change a direction of the first thrust;
• an auxiliary propulsion device attached to the stern, including an electric motor to drive an auxiliary thruster to generate a second thrust, operable to rotate in the right-left direction to change a direction of the second thrust, and having a minimum output smaller than a minimum output of the main propulsion device;
• an operator to receive a user's operation to adjust a speed of the marine vessel;
• and
• a controller configured or programmed to perform an electric drive control to cause the electric motor to drive the auxiliary thruster in the auxiliary propulsion device without performing an engine drive control to cause the engine to drive the main thruster in the main propulsion device when adjusting a thrust of the marine vessel to less than a troll thrust corresponding to a minimum thrust generated when the engine continuously drives the main thruster, and to perform the engine drive control without performing the electric drive control when adjusting the thrust of the marine vessel to the troll thrust or more, when adjusting the speed of the marine vessel by the user's operation on the operator;
• the main thruster is configured to be driven by the engine in the main propulsion device, and not to be driven by the electric motor in the auxiliary propulsion device;
• the auxiliary thruster is configured to be driven by the electric motor in the auxiliary propulsion device, and not to be driven by the engine in the main propulsion device;
• and
• the controller is configured or programmed to shift automatically to a state in which the engine drive control is not performed and the electric drive control is performed when the thrust of the marine vessel is changed from a state equal to or greater than the troll thrust to a state less than the troll thrust when adjusting the speed of the marine vessel by the user's operation on the operator.