Patent ID: 8340846

Claim:
A boat propelling system for propelling a hull, the boat propelling system comprising: a propelling system main body; a bracket section arranged to allow the propelling system main body to pivot in a right-left direction with respect to the hull; an electric motor provided in the bracket section to pivot the propelling system main body in the right-left direction; a transmission mechanism provided in the bracket section to transmit a driving force of the electric motor to the propelling system main body; an actual pivot angle detection section arranged to detect an actual pivot angle of the propelling system main body; a first information obtaining section arranged to obtain first information regarding an actual pivot angle change amount of the propelling system main body based on a detection result of the actual pivot angle detection section; a second information obtaining section arranged to obtain second information regarding a calculated theoretical pivot angle change amount of the propelling system main body based on a drive amount of the electric motor; and a determination section arranged to determine that an operation accuracy of the transmission mechanism is not within a tolerable range if a gap amount between the first information and the second information is greater than or equal to a threshold value, and to determine that the operation accuracy of the transmission mechanism is within the tolerable range if the gap amount between the first information and the second information is less than the threshold value.