What you find if you book Ernestos boat is a small bunk (room) on his boat. He lives on the boat, so you share it with him and even other guests (1-2), that have possibly booked the bunk on the other side of the stairs. The common spaces like table and kitchen are used by him. During the day you don't have the possibility to get on the boat because Ernesto is out for day-tours starting at 11. Coming back something between 16-19h.
Breakfast, as indicated is arranged at a bar in the park (6min walk), I had to ask for it, so he payed. It is a place to sleep, but not a place to enjoy or relax, even though the marina is quiet and beautiful. I wouldn't go back.