Patent attributes
A boat propulsion system includes a gear shift mechanism arranged to transmit a driving force generated by an engine to first and second propellers at one of at least a low speed reduction ratio and a high speed reduction ratio, and a control section arranged to perform control so as to shift a speed reduction ratio of the gear shift mechanism based on first and second gear shift control maps when an acceleration command from a user is detected. The first and second gear shift control maps define a region to shift the speed reduction ratio of the gear shift mechanism using two parameters, preferably a rotational speed of the engine and a lever opening degree of a lever of a control lever portion. The boat propulsion system achieves both the acceleration performance and the maximum speed desired by a user.
