Patent ID: 8463484

Claim:
A marine vessel theft deterrent apparatus for a marine vessel which includes a propulsion device, the marine vessel theft deterrent apparatus comprising: an authentication unit; a fault detection unit to detect a fault of the authentication unit; and an operation control unit to control operation of the propulsion device in accordance with whether the authentication unit is in a locked state or an unlocked state when the fault detection unit has not detected the fault of the authentication unit, and to control the operation of the propulsion device without referring to whether the authentication unit is in the locked state or the unlocked state when the fault detection unit has detected the fault of the authentication unit; wherein the authentication unit enters the unlocked state upon a successful authentication of an unlock signal that is received while the authentication unit is in the locked state; the operation control unit allows starting of the propulsion device and sets an operation mode of the propulsion device to an ordinary operation mode under a condition that the authentication unit is in the unlocked state and prohibits the starting of the propulsion device if the authentication unit is in the locked state when the fault detection unit has not detected the fault of the authentication unit; the operation control unit allows starting of the propulsion device without judging whether the authentication unit is in the locked state or the unlocked state, and sets the operation mode of the propulsion device to an emergency operation mode in which a predetermined restriction is applied as compared to the ordinary operation mode when the fault detection unit has detected the fault of the authentication unit; and the authentication unit includes a signal transmission unit to transmit a signal at a predetermined time period to the fault detection unit, and the fault detection unit judges that a fault has occurred in the authentication unit when the signal from the signal transmission unit is interrupted for a second predetermined time period that is longer than the predetermined time period.