Abstract: A marine propeller including an inner hub to receive a driving connection to the engine and an outer hub is spaced outwardly from the inner hub to provide a passage therebetween for the discharge of exhaust gas from the engine. A plurality of blades extend outwardly from the outer hub. A propeller is die cast from an aluminum alloy and as cast the outer surface hub is cylindrical in configuration. After casting the trailing end of the outer hub is swaged outwardly by a tapered tool to provide an outwardly flared trailing end, which assists gas flow and enhances performance of the engine.