Watercraft propulsion system, and watercraft

Abstract

A watercraft propulsion system includes 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. The controller includes 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. The controller is 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.

What is claimed is: 
     
         1 . 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.   
     
     
         2 . The watercraft propulsion system according to  claim 1 , 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. 
     
     
         3 . The watercraft propulsion system according to  claim 1 , 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, and to restrict a control mode from being switched to the combined use mode if the propeller of the auxiliary propulsion device is in the above-water position. 
     
     
         4 . The watercraft propulsion system according to  claim 1 , further comprising:
 a command input operable by an operator to command to switch a control mode to the combined use mode; wherein   the controller is configured or programmed to actuate the lift to locate the propeller of the auxiliary propulsion device in the underwater position if the combined use mode is commanded by the command input.   
     
     
         5 . The watercraft propulsion system according to  claim 1 , wherein the combined use mode includes a holding mode in which at least one of a position and an azimuth of the hull is maintained. 
     
     
         6 . The watercraft propulsion system according to  claim 1 , wherein
 the main propulsion device is an engine propulsion device including an engine as its power source; and   the auxiliary propulsion device is an electric propulsion device including an electric motor as its power source.   
     
     
         7 . The watercraft propulsion system according to  claim 1 , wherein the main propulsion device and the auxiliary propulsion device are attached to a stern of the hull. 
     
     
         8 . The watercraft propulsion system according to  claim 1 , wherein the controller is configured or programmed to prohibit the main propulsion device and the auxiliary propulsion device from being driven in the combined use mode when the propeller of the auxiliary propulsion device is in the above-water position. 
     
     
         9 . The watercraft propulsion system according to  claim 1 , wherein the controller is configured or programmed to limit maximum outputs of the main propulsion device and the auxiliary propulsion device in the combined use mode when the propeller of the auxiliary propulsion device is in the above-water position. 
     
     
         10 . 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 configured or programmed to restrict the auxiliary propulsion device from being driven when the propeller of the auxiliary propulsion device is in the above-water position.   
     
     
         11 . A watercraft propulsion system comprising:
 an electric propulsion device attachable to a hull;   a lift to move up and down a propeller of the electric propulsion device between an underwater position and an above-water position; and   a controller including a plurality of control modes including a holding mode in which at least one of a position and an azimuth of the hull is maintained, and configured or programmed to restrict the electric propulsion device from being driven according to the holding mode when the propeller of the electric propulsion device is in the above-water position.   
     
     
         12 . A watercraft propulsion system comprising:
 a propulsion device attachable to a hull;   a lift to move up and down a propeller of the propulsion device between an underwater position and an above-water position;   a controller including a plurality of control modes including a holding mode in which at least one of a position and an azimuth of the hull is maintained; and   a command input operable by an operator to command to switch a control mode to the holding mode; wherein   the controller is configured or programmed to actuate the lift to locate the propeller of the propulsion device in the underwater position if the holding mode is commanded by the command input, and to keep restricting or prohibiting the propulsion device from being driven until the propeller of the propulsion device is located in the underwater position.   
     
     
         13 . A watercraft comprising:
 a hull; and   the watercraft propulsion system according to  claim 1  provided on the hull.   
     
     
         14 . A watercraft comprising:
 a hull; and   the watercraft propulsion system according to claim  10  provided on the hull.   
     
     
         15 . A watercraft comprising:
 a hull; and   the watercraft propulsion system according to claim  11  provided on the hull.   
     
     
         16 . A watercraft comprising:
 a hull; and   the watercraft propulsion system according to claim  12  provided on the hull.