Full-time RVers are often in the same situation where they live full-time on their RV and don't rent or own a home in any State. South Dakota is one of their favorite places to become domiciled. SD actually encourages it as a way of gaining much needed revenue principally from vehicle registrations. It's just a matter of traveling to SD to apply for drivers license, voter registration, signing up with a mail forwarding service, and if applicable registering vehicle(s). Of course, to be certain that it sticks, one must break ties with other States. I wonder if the factors that make SD such a good domicile for RVers would apply to full-time liveaboard cruisers?
You can see here that the issue of domicile is alive and well in the full-time RVing world:
Rumblings from South Dakota could affect some fulltime RV folk - Escapees Discussion Forum