I just got back from an 11 day stay at the Aura! Beautiful resort with the best service I have every received at any of my stays in the Caribbean/Mexico. Unforunately, when I went I was not a diver and the diving crash course would have probably ruined the experience for my wife but, it did inspire us both to get certified in the states before our next trip. With that said I did snorkel at least everday right off the beach at the resort and went on two snorkeling excursions to the Palancar, Colombia and a spot they call Hollywood. Just snorkeling we saw the amazing reef structures, numerous barracuda's, nurse sharks, sea turtles...etc.
In talking to the many divers at the resort they raved about the "Wreck Dive" and the "Santa Rosa Wall" to name a few but, like others said you really cant go wrong. Many of them used the dive company Dive Palancar which is right at the resort and they seemed to be happy with the prices and service. I liked the guides so much for snorkeling I gave them a hefy tip after each trip and even bought one of their shirts.
The trip also inspired me to re-do the aquascaping in my tank emulating some of the reef structures that I saw snorkeling which I am looking forward to this weekend.
Also, dont pay attention to what looks like a dismal weather forecast everday when you try and check the weather online. Out of the 11 days it rained for an entire day only once with pop up thunder showers daily that lasted 5min or less.
Let me know if you have any questions about the resort. Have a great trip!