Patent ID: 8038491

Claim:
A boat comprising: an output shaft extending from an engine toward a rear portion of a hull and arranged to output power from the engine; an intermediate member including an internal thread connected to an external thread of the output shaft defining a screw connection between the intermediate member and the output shaft; a coupling including an internal thread connected to an external thread of the intermediate member defining a screw connection between the coupling and the intermediate member; and a reinforcing member arranged to reinforce at least one of the screw connection between the output shaft and the intermediate member and the screw connection between the intermediate member and the coupling; wherein the external thread of the output shaft is provided on a rear end portion of an outer circumferential surface of the output shaft; the internal thread on the intermediate member includes a front internal thread arranged to be screwed to the external thread of the output shaft, the front internal thread is provided on a front portion of an inner circumferential surface of the intermediate member; the external thread of the output shaft and the front internal thread are screwed together to fix the rear end portion of the output shaft in the intermediate member; the reinforcing member includes an inner bolt provided with an external thread arranged to be screwed to a rear portion of the front internal thread of the intermediate member; and the inner bolt is screwed to the rear portion of the front internal thread of the intermediate member to apply tension to a rear end surface of the output shaft and thereby strengthen the connection between the output shaft and the intermediate member.