Check your intake hose!
 

On Saturday I decided it was time to winterize. Everything was going great until I dropped the port engine drain plug into the bilge. It took me 2 hours to find. What a pain. But, while I was looking for it I discovered that my raw water intake hose had been rubbing against an engine mount and was about 98% worn through. Since I keep my boat in a slip, a total rupture would've been really, really bad. So, check your intake hose when you winterize!

Good catch and better advice, but if your boat stays in the water (not on a lift) I would recommend closing all thru-hull seacocks. Takes just seconds and is really cheap insurance!

That's a good idea! I put valves on all my ballast intakes but the raw water intake doesn't have one. Another project for the winter . . . .