Check your homeowners policy, Were with USAA, they (as most do) cover vessels up to 26 feet, and less then 50 horse I/B or O/B. It's really only good for liability, to cover theft it has to be on your property. Check into it. Even it they don't they maybe able to amend a policy to it for a few bucks a month. It cover your A$$ should you or your boat run over a new expensive boat, or a friend of a friend of a friend falls off and sues ya.
It's best to have at least liability.