Sorry if this has already been pointed out: In the final shot of the film, yes, anyone can clearly see the dolphins are badly superimposed over the footage of the actors, but did you guys notice, they didn't even bother to film both dolphins? They filmed one dolphin, and copy/paste/flipped it to get the other dolphin. Through the whole action of them rising up, they, complete with the water splashes, are a perfect mirror image of each other!