Here's a map of Highbourne Cay.
Notice that long beach like edge on the eastern side? Believe it or not, that is actually a beach. We spent a full day there. It was awesome, 28ºC. (Which is doubly awesome because it's -20ºC back home). We played in the waves, hung out with the Haases (if you didn't click that link back there, you really should), and had PB&J sandwiches for lunch.
After we were all sufficiently sunburnt, we headed back, picked up some lobster tails and stone crab claws from local fisherman (water dwelling crustaceans are best crustaceans), and ate them for dinner. T'was delicious.