Marine exhaust system

Claim 1

An exhaust system for a boat powered by an internal combustion engine having an exhaust pipe, said boat having a hull including a hull surface normally submerged below the water level, said system comprising: a. a chamber located within the hull including inlet means located above the normal water level and adapted to be connected to the exhaust pipe of the internal combustion engine; b. exhaust vent means communicating the interior of said chamber with atmosphere, said vent means located at a location normally above the water level; and c. exhaust port means communicating said chamber interior with a location below the normal water level, said exhaust port means including a recess in said hull surface, said recess having a surface extending generally forwardly and upwardly in said hull surface, said recess defining an opening at a generally forward location therein and spaced upwardly from the plane of said hull surface, whereby exhaust is permitted to excape from said chamber at said exhaust vent means when said boat is idling and whereby exhaust is drawn from said exhaust chamber under the influence of water flow at said port when said boat is underway thereby reducing exhaust noise.