The dolphins kept slapping their tails above the water and I kept tying to catch that missing over and over. Here 2 of them slap in a row with a 3rd ready to go while two pelicans were flying over. This was the only time I caught a tail in the air (that sounds like an inappropriate thing to say!)
I tired to look up why they slap their tails like that. I thought they might be trying to stun fish on the surface but could not find anything to support that theory so we will just go with they were having fun.