PA is a very pleasant place to stay. If you decide you have had enough of all-inclusive food, there are a number of restaurants by the dolphin pens. I am not at all familiar with the dive op at your hotel, but both Dive Aventuras and Aquanauts have pretty good reputations. My husband has been out with Aquanauts and was happy; I know a couple of the folks at Dive Aventuras, and they're good people. The viz, as I understand it, does not tend to be the 100 feet of Cozumel, but the reefs are interesting and there are some pelagics that are seen there that aren't common in Coz. From what my husband said, you won't be unhappy to have dived there. (Me, I can't be dragged out of the caves long enough to find out what the salt water diving has to offer!)