We spent the day in XCaret. We did not do the dolphin swim, but we saw many people who did and they appeared to have a great time. There are different options - one was snorkle with the dolphins, waist-deep water, dolphins come up to you and you can kiss them. The other was where the swimmer positioned themselves in the water and two dolphins came from behind and actually lifted the swimmer up and swam with them several hundred feet along the waterway. If I'm not mistaken, you can also go into bigger waterways and actually swim around with the dolphins. XCaret is GREAT! and everyone we saw that did any of the water events in the park seemed to enjoy themselves tremendously.