We haven't done the sea turtle release. But if I was you, I'd totally go to Akumal. That is our favorite place to go while down there. They have a sea turtle preserve and we've seen sea turtles while snorkeling every time. There is also an amazing lagoon to snorkel and swim in as well. It's a small quiet town...........well it was. Last time we were there 2 years ago, they were building a large hotel right next to the town. Not sure how much more crowded it is now.