Nomads in boats

I saw a video of orcas herding a penguin, and looked at the boat trips available for diving off the Great Barrier Reef, and read a little bit about Somali pirates and a bit about nomads. Had this vision of a tribe of sea-going nomads, with their yurts on their boats, following the fish and using dolphins to herd them, wandering up and down the coast. They'd be sea-going Mongols, for all in tents and porpoises.