Yesterday, I was looking around the boat and trying to catalog all of my through-hulls, and found what I thought was the raw water cooling through hull, on the port side just aft of the lower access hatch under the sink. (Remember, there's a higher access plate on the foward face of the bulkhead, which gives access to the sink plumbing; the lower access plate is outboard of the forward engine cover.) So, anyway, I located this through-hull, and it was turned off. Which worried me, if it's the engine cooling through-hull. So I turned it on. And immediately heard the sound of running--or shall I say, flooding--water. And then the sound of the bilge pump. So I turned the through-hull off and tried to figure out where this hose should go. I was limited in the time I could spend, so I didn't finish my investigations. I'll have to go back up to the boat and spend some quality time on my stomach to figure this out. In the meantime, I am taking the awe-inspiring step of asking all my fellow C30 owners to take a second shot at me. So: ... (1) Do you have any idea what this problem hose would be and (2) WHERE would you suspect I would find the raw water intake for the engine?