We did the dolphin encounter in Cozumel last year. I thought it was fun. I know my family loved it. I would say it was worth it. You can book a Dolphin Swim on your own too but not as a disney Excursion (at least on the 7 day). I have read lots of posts that indicate this is the way to go. We loved the encounter but I think the swim would be a once in a lifetime experience.