Howdy!
If they determine that it IS part of a blockade device or perhaps a floating dock that was from the Civil War, and no museum or naval organization wants it they could get rid of it this way. Supposing it has no real value and is simply going to be scrapped, they could cut it up into smallish chunks and sell it. I'd bet they'd be surprised at the amount of pieces they'd sell - look how popular old gym floors are selling when they tear down an old University gymnasium and sell it to their students, alumni and others.