A boat is barely on your homeowners policy
Most forms cap watercraft at a few thousand dollars and exclude liability once the vessel is in use. On a lake this size, with this much traffic, the liability is the exposure that matters: a collision or an injured passenger is not a property claim. A separate watercraft policy covers hull, liability and the people aboard.
Visitors staying in houses
A property rented to guests is in commercial use, which personal homeowners forms exclude or limit heavily. In a town where the season is the economy, that gap sits under a large number of otherwise ordinary policies.
Distance is a rated factor
Remoteness affects response times, repair logistics and which carriers will write at all. It also means a total loss takes longer to put right, which is what loss of use and additional living expense are for and why their limits deserve a look.