Re: Winter under a tarp
I'm a little (all right, a lot) late to this thread. But I do have a lot of experience with both tarps and shrink wrap, so I'll share some lessons learned:
Shrink wrap is a great idea, but I've never seen a yard that didn't cause some damage while putting up the frame and shrink wrap. And very few come out 100% perfect. There are always a few casualties during every wind or snow storm. So the whole "Set it and forget it" strategy really doesn't apply if you care about your boat. Unless maybe you did the shrink wrapping yourself.
There are two things you need to do right if you want your tarp to last the season:
1) Have a sharp pitch. As someone mentioned, snow doesn't slide off a tarp as well as shrink wrap. The only workable solution is a tall "A" frame that goes right up to the gunwale or rail.
2) Keep it tight. I've tried using bottles as weights, and it works. But lately I've changed to using shock cord pulled tight. If it flaps anywhere, or the wind can get under it anywhere, you've lost.
Probably the two biggest mistakes I see are allowing it to get loose somewhere, and allow water or snow to "pool" instead of slide off.
Using a spider web of small stuff (dollar store clothes line works great) can help avoid pooling, but ultimately the design of your "A" is more important. I've seen pooling where the tarp turns just a little over a rail. Once it starts to pool, you have to keep pulling it tight after each rain or snow because the pool will grow, ripping the tarp and supports. Then re-engineer that location next year.
I can walk through a boat yard this time of year and pretty accurately predict whose tarps will last, and whose won't. Those who put in a serious effort to keep them tight are almost always OK. Those who ignored even one slack area will lave lost the tarp by spring.