They have an extremely large network of friends and supporters, and they often mention the people they meet while at marinas. People who live on the water have each other as neighbors.

It’s similar to people who live in their RVs full time. When they park somewhere (often for months) they have local neighbors and meet people. They may often meet the same people later in a different location.

Or you could think of them like long haul truckers, who have friends at their end stops but spend a lot of time traveling. Surely those people live in a society? What about salespeople who constantly travel between a few cities in a region? Or UK longboat dwellers? Bedouins?

Nomadic lifestyles, of one kind or another, have been a part of human history since the beginning.

Regardless, I’m not sure what your complaint is. Care to spell it out in a little more detail for me? You seem to think they don’t interact with people, but that’s not the case.