When you buy a real marine
policy (as opposed to auto insurance companies that also insure boats) the insurance company will ask what layup
period you want and they will usually quote a lower price
if there is a significant layup
period, say 4 to 6 months out of the year.
This doesn't mean that you don't have insurance during this period. You do and it will satisfy your marina. But the risks of hull
or liability loss are much less during the layup period and so they will give you a lower price
This is SOP in the northeast.