I don't know of any place specific, but here in the Tampa Bay area there are often slips advertised on craigslist. Usually people with waterfront homes, with a dock
, who don't own their own boat
. These typically go for somewhere between 1/4th and 1/2 what the marinas
charge. Don't usually allow liveaboards, though.
Good luck finding something, but remember that you very often get what you pay for.