I just want to point out that the other commenter's experience isn't universal. My mom lived on a boat for years and loved it. I couldn't do it long term as there's very little space available, but it doesn't have to be a negative experience.
This particular marina had bathrooms with showers up on land which the majority of, if not all, residents used. There was also a restaurant on the water with bathrooms. Electricity and tap water were available at each slip. Heat wasn't necessary, because it was Southern California.
I never knew how much it cost, but I know for a while she lived there while working as a waitress at that same restaurant, so it couldn't have been too expensive.