I learned something about preparing my boat for the winter that I wanted to share with my fellow sailors. My water faucets never seemed to function properly even though I took special care to drain my fresh water system every winter. What I realized, after replacing my faucet check valves twice, was that even though I completely drained my water tank and blew out the water lines, water still remained above the one way check valve and would freeze and crack the plastic check valves. I now remove the check valves and drain them. No more problems.