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.