Abstract: A method and apparatus for preventing exhaust fumes from entering the deck area of a motor boat having an engine of the type which has an exhaust port that expels fumes at the rear end of the boat is disclosed. The present invention includes an air manifold located at the rear end of the boat above the exhaust port and adapted to direct air to the rear of the boat. Air ducts having inlets located forwardly of the rear end of the boat are connected to the air manifold. The air manifold assembly is configured to form an air barrier between exhaust fumes and the rear deck area of the boat to prevent exhaust fumes from flowing into the rear deck or the cabin area.