The Vernay Muffler available thru Defender Marine page 187 in 99 catalogue, 800-628-8225 was installed in many C&C's. There are numerous choices, but the elongated, horizontal model works fine. The Vetus brand also is excellent and is priced reasonably, long lasting and does what you expect.Get a model with a drain screw or be sure to winterize well because water will be trapped in exhaust system.