This is a 30-minute swim with the dolphins where you do everything you do in the other encounter, but you get in the water with two dolphins, and you're not supported by a platform. They jump over you like a hurdle, and they do what the brochure calls "the incredible foot push." I watched a couple of people be pushed by the dolphins, and it looked... "incredible." No, I think that it was pretty cool looking. Worth the money? You be the judge of that.
This is the one where you sit in a little secluded pontoon and you can pet the dolphins and everything. What you do is you wait your turn to be called with your family, and you go into the water, pet the dolphin, dance with it, hug it, kiss it (both for a charming picture) and if you're lucky, you'll get water spit in the face. This actual encounter takes about 20 minutes, although the advertisements stretch the truth a little bit. It's three hours from the time you leave the pier to the time you get back. Not the duration of the encounter. It costs $85, and is a good program for your kids who can't quite swim yet.
This is something that's fairly expensive to do, so don't put your money into it unless you know your family is going to really appreciate it. There are two different encounters, one is like a petting-zoo type thing where the doplhin does some fun tricks and they video tape you and take some pictures to sell; the other is where you go into a more expansive body of water and you get to swim with the dolphins. By swimming with the dolphins, I mean getting in the water and being pushed out of the water, somewhat gliding, by the dolphins. You can choose to observe your family members as well for the innocent fee of $20 for the boat ride.