Freeze damage
In addition to the exposure to weather, the decision to cover, which virtually everyone here in New England does, is based on freeze damage. If you have any leaks, and almost all boats do even if they are not obvious, the expansion of trapped water is something you want to avoid. We have always covered ours but some of our friends didn't and found their previously dry boats now leaked.We store in the water every other year and it's a simple matter to tie off the cover to the slotted toe rail or, in lieu of the toe rail, tie off to the stanchions and cleats.