I have been searching for the source of a small saltwater leak to no avail. After running the engine, a small amount (6-8oz) of 'dirty' saltwater settles in the small sump under the propeller shaft.The dirty water is brownish and I never get any water until after the engine has been shutdown. I've done enough investigating to convince myself it is not coming from the shaft seal. My thought is that I might have pinhole leak in the engine exhaust pipe aft of the exhaust/water muffler. While the engine is running the water would be moving past the hole and when it shuts down maybe it settles at a low point and leaks out.Anyone have any thoughts?