I don't know if this is the same one that you're talking about, but when I went to Atlantis (aka, Heaven on Earth) last year, we took a boat to swim with the dolphins.
There were two programs, I believe the Dolphin Discovery and the Swim with the Dolphins.
I did Dolphin Discovery along with my sister, brother, and younger cousins. The cousin my age did the swimming with the dolphins, which was more expensive. I would've done it with her, except we booked too late.
It was amazing. The difference between the two was that my cousin was able to be pushed along the water by the dolphins, and they leaped over her. But we fed the dolphins, got hugs and kisses, pet them, got splashed...there was alot of interacting between the humans and dolphins.
The experience was wonderful, I would love to do it again! I wanted to do it, but I didn't realize how amazing it would be.