Experienced salvor
I work in a boat yard in Biloxi and have delt with this many times since Katrina. Have your friend buy the boat from the yard at the least expense. Apply with the Coast guard for salvage rights. Make sure they know the boat was already on the hard and scheduled for demolition, or they will have expected you to leave it alone. It will take a year for the CG to free the salvage rights, but they should take care of all the "notifications" of which there really are none. In the mean time the original owner or insurance company will most likely not appear, but at the least they will be required to pay what ever cost you incured to obtain the boat as long as they are with in reason. After a year has passed the Coasties won't just grant you the rights to the boat, but you can doccument your efforts. Take these doccuments to what ever state agency registers boats in your area and register it. A simple bill of sale from the yard that has it now will likely suffice. Use your documentation later if someone pursues the boat in the future (ie, don't ask for permission, ask for forgivness). The main goal here is not to look like a thief. Let the CG know you are looking for the owner, wait a year, then register. If down the road an individual or agency with claim to the boat appears at the very least they will have to reimburse you for improvements, costs, or repairs that you made in good faith with no ill intent. You may want to contact your local chapter of the "Yellow Pirates" AKA SeaTow, they have alot of experience with stealing, I mean salvaging boats, and for a good pay off I am sure they can help.