My favorite science fiction author as a child is Tais Teng. In one of his books he wrote about the “Atlantic Empire”, a floating nation of (former) refugees. At the time I found it an exiting idea, a sea-based society, but I did not believe that it would become reality.
However, today we see many people fleeing from their homes and they are willing to risk their lives by boarding boats in order to cross the Mediterranean. But in Europe they are hardly welcome. It’s not hard to imagine that refugees might opt to stay at sea instead of mere travel.
Perhaps some charity might even go so far to buy old cruise ships to accommodate those refugees. And from there it will be a small step to develop an ocean-dwelling society, which would cut all ties to the shores. In the end we will arrive at the Atlantic Empire.