Not a marine lawyer, but used to work with a chick whose family got screwed in a "salvage" deal (that was her story anyway).

Basically, salvage is primarily (only?) for boats abandoned at sea. Depending on the laws, someone who comes upon an abandoned boat can claim half (more/less) of its value from the owner. I think they can push to take ownership if you don't pay.

Avalon is right, more likely an abandoned property issue. Those are a crapshoot. It's amazing how people who completely forget about their property for years become extremely concerned when someone starts talking about taking it from them.

Mike