The marina will certainly have a policy to cover their liability. However more to the point - The marina almost certainly requires in their contracts that the boat owner add the marina as an additional insured to the Boat Owner's Insurance polity, likely with a waiver of subrogation in favor of the marina. As a consequence of that the inevitable insurance claims would play out like this: Boat owner claims on his/her insurance. Boat owner's insurance (BOI) pays the claim for loss of the boat and salvage costs and starts thinking about subrogating against the potentially liable parties. BOI can not subrogate against another insured on the policy and notes that BOI has added marina as an insured. Therefore BOI cannot proceed against Marina. BOI then looks at other potential sources of liability. Can another boat owner (BO2) be held responsible for starting the fire? If so BOI subrogates against BO2. BO2 passes this claim to his/her insurer. Insurers exchange allegations and ultimately apportion the insurance claim between them. Meanwhile the marina's insurance pays for the physical damage to the docks, and works with individual boat owners and their insurances regarding the costs to remove the presumably sunk boats. Those expenses would be recoverable by the marina from the BOI. ~Alan