Marine engine noise suppressor

An exhaust system for an internal combustion engine of a boat having a planing hull with a bottom surface and with a rear hull wall at its rearward end and a stationary water line above the lower surface of said hull comprising,

• a) an internal combustion engine having an exhaust manifold,
• b) an exhaust chamber in said hull, with said chamber having a forward wall, a top wall, a pair of spaced side walls and with said rear hull wall forming the rear wall of said chamber and with said bottom surface of said hull forming the bottom of said chamber,
• c) conducting means connecting said exhaust manifold to said exhaust chamber at a level above the water line of said hull,
• d) a vacuum wedge in said exhaust chamber having
• i) a wedge plate having a front edge, a rear edge and a pair of side edges, with said front edge being connected to said forward wall at a location above said lower surface of said hull and extending angularly rearwardly and downwardly therefrom and with said rear edge directly connected to the junction of said rear hull wall and said lower surface of said hull,
• ii) said wedge plate having a first vertically extending opening therein intermediate the front and rear edges thereof, and
• iii) said lower surface of said hull having a hull opening open beneath said wedge plate whereby said vacuum wedge provides a high speed exhaust path from said exhaust chamber through said hull opening, and
• e) low speed exhaust path means connecting to said exhaust chamber at a location above said stationary water line extending to open outside said hull at a location above said stationary water line.