Powerboats use marine mufflers , generally manufactured from non-metallic stuff, to reduce engine noise and moderate the exhaust. Mufflers are always installed over the waterline, and normally have some kind of check valve in-line to restrict backward water flow, which might harm the engine. Along with it, you can also understand by this explanation- Boat exhaust mufflers are stainless steel machines fitted within the exhaust system connecting the engine and the end of the exhaust pipe. They decrease engine sound, deplete exhaust gases and stop water from entering the engine. Those allowed on NauticExpo are meant for usage on leisure craft. Applications and Technology used in Mufflers : · These machines are spotted on almost every engine intended for recreational boating. · There are different kinds of shape's mufflers like vertical, round and goose-neck models. · They are usually made of PVC, also some are stainless steel. The