I look at a lot of dealer short sales as well as repo boats and found a few sites worth frequenting. Nat'l Liquidators "auctions" off bank repossessions but their boats typically carry a reserve price..but even still I've found bargains there.
I avoid salvage but if you're into damaged boats or parts sites like IAAI and Copart are good. I find a good mix of power and sail boats listed as
repo boats at Boat Auctions Direct. Key is to use as many sites as possible to stay sharp.