The one winter....
... I decided to leave my boat in the water was a nightmare. It got cold early that year and ice began to form in the marina (which is mildly salty). Then it warmed up and rained. Then it got cold and the ice returned. I visited the boat often, and once found the dock lines, which had gotten wet, were now frozen, had no "give" and there were sharp edges where they rounded the pilings. A few weeks later, we had an unusually big snowstorm. I attempted to get to the boat. I had to leave my car at the edge of the marina and walk through about 15 inches of snow to get to the docks. Then I realized how dangerous it would be to walk down the snow covered docks. I did it anyway. Have you ever been on a boat covered with snow? Sort of sporty. My boat, which had some tarps over it, still had about of foot of snow on the side decks. It appeared thatleaves had somehow gotten into the cockpit and frozen over the scuppers. About 6 inches of ice had formed there. I was not a happy camper. In the end, the boat survived the ordeal of winter better than I did, with only a few minor scratches at the waterline where the hull chaffed against ice the froze, melted, and refroze. I'll never leave my boat in the water again in winter in a place where ice forms and it snows. The boat can take it, but I can't.