River Cities is selling floating condos that will travel through the intra-coastal waterways of the U.S., from St. Paul Minnesota, to Port Isabel Texas. I'm not sure this would hit enough interesting places to make it worth buying a condo, but with 30 or more cities listed as stops, I'm sure you could find something to do. It appears that The Marquette, the first ship to be built, will be somewhat like a barge, allowing it to travel the shallow waterways.
The Marquette is billed as a floating city, and comes complete with a grocery store, restaurants, concierge service, a rooftop lounge, theaters, activity rooms, a library, hot tubs and pools, fitness equipment, walking tracks, and a rooftop chipping course. The condos range from "The Illinois" at 528 sq.ft. costing $299,000 up to "The Mississippi" at 924 sq.ft. costing $499,000. There are a few areas where you can get a custom floor plan, and I'm sure price depends on what you want in it.
You can read more about The Marquette at their site HERE.