I lived on My sail boat for the better part of 12 years. In my travels I did see some strange floating "homes" Some were really not boats, some not even house boats. Most of these were in the Florida Keys. Anything that would float covered over with scraps of wood and some structure to give some shelter & tied to the mangrove bushes, they were home to somebody... I think the ones I saw have not survived the huricanes, but no doubt there are others in their place.
Key West has a large homeless population, or at least it did then, living in the bush near the airport. Those people don't even have a "houseboat". They break camp every day and go to the beach., the cops won't go in the bush after dark, so they don't get hassled at night.