[jclark003]

Strange. Maybe fill the FW tank again and see if the water returns. Although I still think a leaking tank would show water in the forward bilges, not under an engine. You can also try to mop up all the water, get it good and dry down there, and sprinkle a line of talc powder around the parimiter of the compartment. Wherever the water is coming from will wash away the talc leaving a trail. Blue shop towels work too. Is the hot water tank mounted outside of that engine?

Sometimes weeds or duck weed can get in the to shaft seal causing it to leak temporarily. Running the boat for a bit can clean the surfaces and cause the seal to mate properly again.