Be sure to plan way ahead and check with all of the marinas/yacht clubs you might be interested in–in fact, visit them if you can. In San Diego, most have waiting lists, and can be expensive, so research is key.
As long-time residents of San Diego, we prefer keeping our home, with our boats at a club, but that’s just us. Living exclusively on a boat works out very well for many people.
Here’s an article I’ve sent friends who are considering living on a boat in San Diego that you might find interesting:
http://www.businessinsider.com/couple-took-out-a-mortgage-on-a-boat-instead-of-buying-a-house-2015-5
I would think that as an airbnb a boat would be quit attractive, is there already such a thing?