Be real careful of water pooling. If the tarp is too loose, it will start a puddle and that puddle will continue to grow until your mast is bent like a toothpick. Whenever I use a tarp to cover a boat, I cut a few drainage holes in it so it can't collect excess water.

Custom hull covers are definitely the way to go if you can do it. They'll keep the hulls in pristine shape and it's like unwrapping a present every time you go sailing.

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