I think using a tarp to cover the boat is ok as long as you make sure it's pulled tight so that it doesn't collect snow or rain water. Be sure to remove any snow that does happen to accumulate.

Loosen or better yet, remove the tramp, and remove any lines. All the hardware/fittings are impervious to weather/cold.

One other thing that I do that I didn't see mentioned is that I like to put my trailer up on blocks so the wheels are off the ground. I'm not sure whether it matters, but I just don't like the idea of having the wheels sit loaded in one position for several months in a row.

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