Safety system and method for watercraft

Abstract

Systems and methods for operating watercraft are provided. One method of operating a watercraft includes detecting a presence of an obstacle in proximity to the watercraft. When a propulsion command is received when the presence of the obstacle is detected, an actual output from a powertrain of the watercraft is restricted to a restricted output associated with the presence of the obstacle.

What is claimed is: 
     
         1 . A method of operating a watercraft, the method comprising:
 when the watercraft is parked, using a proximity sensor of the watercraft to detect a presence of an obstacle in proximity to the watercraft;   when the presence of the obstacle is being detected:
 receiving a propulsion command from an operator of the watercraft, the propulsion command being indicative of a commanded output from a powertrain of the watercraft; and 
 when the commanded output is greater than a restricted output associated with the presence of the obstacle, restricting an actual output from the powertrain to the restricted output in response to the propulsion command. 
   
     
     
         2 . The method as defined in  claim 1 , comprising detecting that the watercraft is parked by detecting an absence of the propulsion command for a prescribed amount of time. 
     
     
         3 . The method as defined in  claim 2 , wherein the prescribed amount of time is between 30 seconds and 600 seconds. 
     
     
         4 . The method as defined in  claim 1 , comprising detecting that the watercraft is parked by detecting a speed of the watercraft being equal to or below a prescribed speed. 
     
     
         5 . The method as defined in  claim 1 , comprising detecting that the watercraft is parked by detecting that the watercraft is stationary. 
     
     
         6 . The method as defined in  claim 1 , wherein:
 using the proximity sensor to detect the presence of the obstacle includes using the proximity sensor to detect that the obstacle is located behind the watercraft; and   the restricted output is associated with the presence of the obstacle being behind the watercraft.   
     
     
         7 . The method as defined in  claim 1 , wherein:
 using the proximity sensor to detect the presence of the obstacle includes using the proximity sensor to detect that the obstacle is located forward of the watercraft; and   the restricted output is associated with the presence of the obstacle being forward of the watercraft.   
     
     
         8 . The method as defined in  claim 1 , wherein using the proximity sensor to detect the presence of the obstacle in proximity to the watercraft includes measuring a distance of the obstacle from the watercraft and determining that the distance is less than or equal to a prescribed distance. 
     
     
         9 . The method as defined in  claim 1 , comprising alerting the operator of the presence of the obstacle. 
     
     
         10 . The method as defined in  claim 1 , comprising communicating to the operator a position of the obstacle relative to the watercraft. 
     
     
         11 . The method as defined in  claim 1 , wherein the restricted output is between 0% and 50% of a maximum output power deliverable by the powertrain of the watercraft. 
     
     
         12 . The method as defined in  claim 1 , wherein restricting the actual output from the powertrain includes preventing propulsion of the watercraft. 
     
     
         13 . The method as defined in  claim 1 , wherein:
 the propulsion command is a first propulsion command;   the method includes, when the presence of the obstacle is being detected:   receiving a second propulsion command from the operator after receiving the first propulsion command; and   executing the second propulsion command without restricting the actual output from the powertrain to the restricted output.   
     
     
         14 . The method as defined in  claim 13 , wherein executing the second propulsion command without restricting the actual output from the powertrain to the restricted output is conditioned upon receiving an override command from the operator after receiving the first propulsion command and before receiving the second propulsion command. 
     
     
         15 . The method as defined in  claim 1 , wherein:
 the propulsion command is a first propulsion command;   the method includes, after restricting the actual output from the powertrain in response to the first propulsion command:
 ceasing to detect the presence of the obstacle using the proximity sensor; 
 receiving a second propulsion command from the operator of the watercraft; and 
 executing the second propulsion command without restricting the actual output from the powertrain to the restricted output. 
   
     
     
         16 . The method as defined in  claim 1 , comprising communicating to the operator how the actual output from the powertrain is being restricted. 
     
     
         17 . An electric watercraft comprising:
 a jet propulsion system;   a motoring battery to power the jet propulsion system;   a proximity sensor to detect a presence of an obstacle in proximity to the electric watercraft;   an accelerator to receive a propulsion command from an operator of the electric watercraft, the propulsion command being indicative of a commanded output from the jet propulsion system; and   a controller operatively connected to the jet propulsion system, to the proximity sensor and to the accelerator, the controller being configured to:
 when a propulsion of the electric watercraft is paused, determine that the presence of the obstacle is being detected by the proximity sensor; and 
 in response to the propulsion command being received when the presence of the obstacle is being detected, restrict an actual output from the jet propulsion system to a restricted output associated with the presence of the obstacle. 
   
     
     
         18 . A method of operating a watercraft having a jet propulsion system, the method comprising:
 using a proximity sensor of the watercraft, detecting an overboard person behind the watercraft;   when the overboard person is being detected:
 receiving a propulsion command from an operator of the watercraft, the propulsion command being indicative of a commanded output from the jet propulsion system of the watercraft; and 
 when the commanded output is greater than a restricted output associated with a detection of the overboard person, restricting an actual output from the jet propulsion system to the restricted output in response to the propulsion command. 
   
     
     
         19 . The method as defined in  claim 18 , wherein detecting the overboard person includes detecting that a temperature of the overboard person is higher than a temperature of water adjacent the overboard person. 
     
     
         20 . The method as defined in  claim 18 , wherein detecting the overboard person includes detecting infrared energy emitted by the overboard person.