Our guide took my wife and I on a 2 mile hike through one of the most bio-diverse places I'd ever been. We saw over 20 varieties of birds, many of them endangered and quite rare. Then we got into the ocean! Amazing. It took a few minutes to the used to the snorkel, but our guide made us feel really confortable and pretty soon we were paddling here and there checking out the colorful fish.
It was a really good time and introduced us to some of the hidden parts of Puerto Viallarta.
The company that runs this tour also spend a lot on preserving the environment. I know that a portion of the money I spent will go towards whale disentanglement and turtle protection. The other tours I did there didn't give back like this one.