If you are going to be in Ixtapa for awhile consider this side trip. My wife and I have bikes here and we ride the bike path from Ixtapa to Playa Linda. After we lock up the bikes we take a water ferry to Ixtapa Island for some snorkeling. It's not Maui when it comes to marine life, but it's not bad for around here.
We usually stake out a spot by one of the many restaurants right on the beach. In fact, you can't avoid them as waiters from the various beach cantinas solicit your attention with hopes you will buy a dinner or at least a beer or two (which we normally do). We hear that the fish is excellent, but we usually don't eat there or if we do, just a snack.