#it fucks me up that this dolphin is obviously not trying very hard#is there some kind of fucking Physics happening here? i don't know of any
He's riding the bow wave! The boat, moving forward, also pushes quite a bit of water forward. The dolphin is letting the boat push him with the water, to save on the effort of swimming. It's like birds that fly in a V formation to take advantage of the wings of the bird ahead of them.
That dolphin is having such a good day that I stop and watch him every time this comes around. Imagine how it must feel, basking in the rush of water, effortlessly carried forward.