I've only stored boats in NY/CT for about 25 winters, so I'm relatively inexperienced compared to some here.
I've used tarps, wood frames, metal conduit frames, and boom tents. I've covered, not covered, used only a cockpit
cover. Never shrink-wrapped because I think it's a waste of materials and money
, and was concerned about breathability. Boats MUST have ventilation or they mildew. A cover for your cockpit
is also a must (unless you can be there after every snowfall to shovel it out) as snow/ice will otherwise block the cockpit skuppers and allow overflow melt-water into spaces it doesn't belong. In terms of preventing damage, if you only cover the cockpit you're 90% there, the next 9% is to cover cabin
ports/windows, the next 1% is everything else.
Tarps do more overall damage than the freeze-thaw because the wind
causes constant movements, and even small shifts will rub the finish over time and turn your shiney gelcoat
to a matte-finish. If you do use tarps, use only heavy-duty ones and weight them with gallon jugs full of water
or sand (even that won't prevent movement). Beware the small pocket that traps water
, which freezes/thaws, traps more water, gets heavier and heavier, and eventually creates a huge ice pocket.
In the last five years I used a Fairclough custom cover I picked up cheap
from the owners of a sister boat. A custom cover is the way to go if you plan to keep your boat more than about 5 years.
BTW if you do shovel a cockpit -- the best tool I found is a child's plastic snow shovel. They're sized properly for the space, and the semi-hard plastic doesn't scratch the fiberglass