Tail slapping wasn’t the only thing that the humpbacks were doing a lot of. Waving with a flipper was also going on a lot. I don’t know what this means but it is cool to see because it makes it seem like the whales are waving at you. Since they are underwater when they do it and can’t see you, they obviously aren’t bothered by our presence but who cares? It feels like you are being waved at!