A generator set (genset) for use in a marine environment is disclosed. The genset includes an alternator, an engine dedicated to driving the alternator, and an exhaust port connected to the engine to receive exhaust generated during operation of the engine to drive the alternator. An inner tubular structure is provided that is configured to receive exhaust gases from the exhaust port and communicate the exhaust gases therethrough. The exhaust processing device also includes an exhaust processing element mounted within the inner tubular structure to process the exhaust gases and an outer tubular structure mounted around the inner tubular structure to form an intermediate space therebetween. The exhaust processing device further includes at least one orifice through which to deliver a flow of water to the intermediate space to maintain the outer tubular structure at a temperature below a temperature of the exhaust processing element.