Patent ID: 7387555

Claim:
A boat exhaust system comprising a boat comprising at least one engine mounted inside the boat, such that the engine produces an exhaust gas, at least one engine exhaust outlet, and at least one propeller mounted upon a propeller shaft wherein the propeller shaft exits the boat's hull under the boat, such that the propeller generates a propwash; a waterline relative to the boat; and an exhaust injection system comprising injection piping, such that the injection piping has a first end connected to the engine exhaust outlet, and a second end positioned below the waterline, aft of and generally in line with the propeller, such that at least a portion of the exhaust gas is exhausted through the second end, in proximity to the propwash, the injection piping comprising a first pipe section, such that the first pipe section is attached to a first engine exhaust; a second pipe section, such that the second pipe section is attached to a second engine exhaust; and a third tee section, attached to the first pipe section, the second pipe section, and the second end, such that the third tee section may pivot away from the boat.