If you're interested in staying at an AI in POP, Playa Dorada has a selection of nice hotels. I've been to Gran Ventana, Victoria and Barcelo. My favorite of the 3 is Gran Ventana, the hotel is very nice, has lots of choices re food options and has good nightly entertainment etc. Victoria is the sister hotel and if you stay there, you get access to both resorts and all the restaurants between both etc. Victoria is smaller and is not located on the beach, it's on the golf course and mainly caters to older clientele but does themed nights in their restaurant and they have a great tex mex beach restaurant. Barcelo was nice but I did not care much for the food. As far as snorkelling goes, I've taken the catamaran excursion offered by Avlav tours twice now from Playa Dorada to Sosusa. They take you out from morning to afternoon, you get lunch and drinks included. They take you to 2 spots for snorkelling and you get to feed the fish etc. If you go to the plaza located in Playa Dorada complex, go to the Avlav counter, there's an American girl who works there. She'll give you a price of $60 but you can get her down to $50. The sharks who try to sell them to you on the beaches or at the hotels charge as much as $90 for the same trip because of the commission. Hope you enjoy your trip!