I agree - Chakanaab is beautiful. we also did the dolphin thing - wow, what an experience. You should be able to get a cab there fairly cheap and you also pay to enter the park if you don't book an excursion. I saw several people in the water so you should be able to snorkle. The water was so beautiful I have never seen a blue like it. Just do an internet search of the park by name and I'm sure you will find all the answers.