Nightmare, call all the marinas and storage yards in your phone book, then get some other phone books in popular boating locales.
Every boatyard has "yard queens" that have been abandoned in the yard, that are behind on storage payments. And in pretty much every state, the yard eventually files a "warehouseman's lien" and takes possession of the boat, after which they sell 'em off as cheap as they can, or pay to have them hauled off and trashed.
The ones that are worthless and have to be hauled away? They'll probably be glad to sell to you for a hundred bucks. Work the phones, your boat is out there.
One word of caution, not all marinas and boat yards negotiate in good faith. I was recently burned by putting money on a "foreclosed" boat, that after I paid for it, I was told that the title "paperwork" wasn't finished. Later I found out they had sold the boat to me without even starting the procedure to inform the owner, wait 30 days for payment, file a lien an the county, ...
While waiting over 6 months for them already holding my money and refusing to refund, (they held the "sale" as leverage against the owner to convince him to pay up).
The boat was stripped, by (disgruntled workers that didn't get paid yet?, the boatyard? the owner that knew he was going to lose the boat?...), after everything, and I mean everything was removed from "MY" boat it was destroyed by a hurricane , (the boatyard made no effort to secure it, but wouldn't let me move it to a secure location), that left it in the middle of the road smashed beyond all repair.
That was when the title was express mailed to me along with a bill for crane service to remove it from the road, and a bill for damages that it supposedly did to their facilities and other boats. (I tore it and the contract up and sent it back).
I could have sued for breach of contract, but the cost would have exceeded what I paid for the boat.
Lesson learned - insure title is clear and ready before putting down a penny. Insure the boat is ready for imediate delivery before paying, as soon as sale is complete, take title, and boat to another location, (possesion is 9/10's of the law).