Here's a thought for you ....
Don't pick a resort for its beach. Pool maybe, but not beach. Then when you want to take a dip, or just wade around, walk the beach. When you see a spot that looks good, just go on in.
I don't believe that you're going to find the type of "beach area" that you may be thinking of that would be typical of an island, on AC. It really won't matter, honest!
I'm not a "pool" person at all, but the pool at Belizean Shores changed my mind. Any cooling off that needed to be done, and quick and easy access to swimming, was done there. I also used the area off their pier.