Abstract: A marine exhaust system is provided for separating the gas from the water of gas/water mixture produced by a marine engine, and expelling the gas a sufficient distance from the hull of a boat to place it outside of the turbulent boundary layer surrounding the hull and the low pressure area following behind the boat. A nozzle having a variable outlet area is mounted amidship on the hull for maintaining a predetermined pressure within the exhaust system in order to expel the gases a maximum distance from the boat. In addition, apparatus is provided for removing the water from the exhaust system prior to the gases reaching an acoustical chamber for attenuating exhaust gas noises.

Abstract: A marine exhaust system is provided for separating the gas from the water of gas/water mixture produced by a marine engine, and expelling the gas a sufficient distance from the hull of a boat to place it outside of the turbulent boundary layer surrounding the hull and the low pressure area following behind the boat. A nozzle having a variable outlet area is mounted anidship on the hull for maintaining a predetermined pressure within the exhaust system in order to expel the gases a maximum distance from the boat. In addition, apparatus are provided for removing the water from the exhaust system prior to the gases reaching an acoustical chamber for attenuating exhaust gas noises.

Abstract: An exhaust gas-cooling water separation chamber, a gas collection chamber and gas acceleration and gas flow-shaping conduit means. The entrance of the separation chamber is connectable to water coolant and gas exhaust tubes from a marine engine. The separation chamber is fitted with a water deflector disposed below the gas exit from that chamber, while a gas dam is disposed in the water exit from that chamber, the entrance and water exit going below the deflector level. The gas collection chamber is connected to the gas exit and a gas acceleration chamber which tapers downstream is connected to the gas collection chamber.