My sister and her husband used to own a marina on Lake of the Ozarks. He was a little bit crazy... I guess still is.
Because he had scuba gear, insurance companies would hire him to bring up sunk boats if they were in an area too shallow to be left in place. So he'd be the type who would scuba, in a crappy lake, into boats and fill them up with bags of air to get them to the surface.
He had one where he had to pull up a boat. 41' cabin cruiser. Insurance company paid him to pull it up, and then offered to sell him the boat for $5K because it was salvage at that point. He knew it had two Ford 427 engines in it, so the cost of buying it--worst case--would probably be recouped just selling the engines.
As it turns out, he got the boat up, realized that it was probably an owner who had pulled the plugs and sunk it for the insurance money, rehabbed it and sold it for over $30K IIRC. Before the sale I stayed on the boat one college Thanksgiving when I went to go visit--you wouldn't have had a clue it had been sunk and salvaged.
He's one of those guys who doesn't have "a job", he just has his irons in so many fires that he's always making money somehow. I don't know if I could handle that life, but I guess that's just how he grew up.