Be careful. I was told by someone in the know that these dolphins are ex-NAVY commando dolphins trained to attached mines to the undersides of ships. If one of them tries to attach a large, plate shaped object to your belly while you swimming, it is just their way of having fun.
Seriously, I did a dolphin encounter type activity at a resort in the Carribean and it was great fun. I hope to check it out next week when we are at the HWV.