These marinas are cities within cities. People in them live semi-nomadic lives and form communities; coming and going with the wind.
The marina in Barcelona reminds me of similar ones close to home. I’m heading back and have been looking at my photos from there. Marinas are enormous along the Mediterranean. We have many in Florida, but I think they are generally not as big as the ones in Europe. Maybe boat life is more prevalent there.
Anyway, I know an American teacher who leads on-line courses remotely from her boat in Spain or Italy, depending on the season. No house required; have a boat, laptop, and internet connection; and the world is your oyster.