The following is a Craigslist post I ran across in the Fort Myers Florida area. I enjoy running into this kind of tenacity, to live on the water cheaply, here's one who built a boat back up literally from scrap:
"If you are looking for a houseboat project, this may be right for you. I ended up with 3 project boats and need to keep one.
For this project I stripped down an old pontoon boat that was floating in a canal for 5 to 10 years. It was a 1995 22 footer with good sized pontoons.
After taking all of the old wood, carpets, parts off. I started from scratch with brand new 3/4" marine plywood, with composite decking on top of that.
The enclosed 12' cabin is constructed of cedar, with pressure treated posts, walls and trim. There is also a front deck sitting area.
It will need a motor, unless you are just going to float it as a live aboard.
Buyer will need to determine how many pontoons to add for flotation and safety, as the boat has not been put in the water, since the decking and enclosed structure were added.
The portable air conditioner is negotiable. Appliances not included. Full-size metal frame futon with extra thick mattress included.
Has full-sized patio sliders front and rear, with matching side windows. Ceiling has clear panels for star viewing. Shade panels could be added by buyer. Interior and exterior trim/floor finishing needed. There is some extra trim wood, included with the sales, along with pontoon primer and bottom paint."
His listing can be found here on Craigslist, and is the source of the post
Here's a similarly adventuresome bunch I think you'll enjoy:
Shantyboat at FIGMENT Oakland from Wes Modes on Vimeo.