A few pointers:
1. Make sure it is clear of all liens not just the banks.
2. Not all banks will have the boat/car inspected and sell ASIS. (see if warranty is transferable.)
3. Be very careful inspecting it and see if you can get a third party to inspect. If the guy cannot make his monthly payments, he most likely was not spending money maintaining it or winterizing it. (Some guys will actually abuse the vehicle before its taken back.)