Patent ID: 7182659

Claim:
An exhaust device for a boat, the boat including a boat body having a hull that forms a boat bottom and a deck that covers the hull, and an engine that is arranged inside the boat body, said exhaust device comprising: an exhaust pipe that leads exhaust gas generated by the engine to the outside of the boat body; and an open/close valve mounted on an outlet of the exhaust pipe, the open/close valve including a valve casing and a valve element that is housed in the valve casing in a vertically movable manner, the valve casing including a cylindrical portion that extends vertically, a through hole formed in the cylindrical portion, a bottom portion mounted on a bottom of the cylindrical portion, and an exhaust inlet mounted on an upper portion of the cylindrical portion, and the valve element including a cylindrical body that is arranged along an inner surface of the cylindrical portion and has a height that allows the through hole to be maintained in an open position, and a sealing plate that covers an upper portion of the cylindrical body and has a size that allows the sealing plate to close the exhaust inlet, wherein when the hull is arranged below the deck, the exhaust gas that enters the valve casing through the exhaust inlet is discharged to the outside of the valve casing through the through hole, and when the hull is arranged above the deck, the sealing plate of the valve element is moved due to gravity to close the exhaust inlet.