Boat insurance is a strange thing. If you park your car in your garage, or yard and don't use it, you get a discount from many companies.
I asked Zurich about the same thing with my boat. They said no.
I am not sure who has the best insurance rates or who handles claims the best, but Zurich was my carrier up in Sacramento, when the night someone broke into a bunch of boats in the Sacramento Marina. Zurich paid the claim, so I try to stay with a company when they take a loss from me...sort of let them get some of their money back. Knock on wood, but no thefts since I have been in WB.
Flutterby, since you put your boat on a lift, any change in your insurance? Did you insure the lift itself?