each policy will be different, and have its own exclusions and coverages, whether it is for car, homeowner or marine coverage. If you place a marine coverage claim on a homeowner or auto policy, the claim will go against that policy. So that will increase that policy cost and another claim against that policy in a 2 - 3 years may result in refusal to renew, or a steep increase in rates. It happens, as
@Outdorman mentioned. Here's a thought for you- a bearing fails travelling down the highway, wheel comes off trailer and hits oncoming car, injures or worse to car occupant. Are you covered? Or bearing fails and you catch it before it fails, but hub assembly is toast - are you covered for towing or road side repairs? I don't know about you, but the thought of leaving my boat on the side of a highway for someone to put on a tow truck, or worse drive into, is not really something I want to consider. I remember in 2020 out at bluffers on Sunday afternoon. A couple hooked their boat and trailer to their car at the end of a day's outing. Went to visit their friend for an hour. Came back and the boat and trailer were gone. The thieves just unhooked it and took it away. Or, your electrics and motor fail in 61 fow off Burwell in 3 - 4 foot waves - are you covered for C-Tow? Boat sinks like we saw happen at Port Stanley or any one of 100 ways we have seen it happen, is salvage and environmental covered? Are you that wealthy?
A marine policy will also cover you if you hit a deadhead or rock and damage the motor or boat. If you operate in the dark (pre dawn, after sunset) I would think that is something you would want? I think about some of the logs I have seen in the water on my way out to the fishing grounds and cross my fingers every day I hot lake O in the pre dawn darkness. My policy also covers loss of use - they will provide me a rental replacement while mine is down, or stolen, to a maximum amount.
I don't doubt for a moment what
@G.Mech says is correct for some policies, while others will cover boat and trailer You really need to read the policies. I have more than once been told something over the phone that didn't agree with the wordings of the policy. In a classic case, my broker recommended we switch homeowner insurance to reduce our costs the year before I bought the new boat. When I bought the new one, I called to see if the homeowner policy would cover the value of the new boat (it was 3.5 times what the old one was), I was told that unlike the previous policy, the new one did not extend coverage to the boat. I didn't think about it at the time we switched and nor did the broker. Fortunately for me and the broker, I didn't need it in those 10 months. Lesson learned.
60+ years has taught me sh#t happens. Once it hits the fan, its too late if you ain't prepared.