Although Cistern Cay Beach is not very wide (approximately 2500 ft. long x 50 ft. wide), it does have soft, powdery white sand.
It is directly across from Cistern Cay, where you can find some terrific snorkeling.
Even though this is an Atlantic side beach, it's waters are protected by Whale Point and Harbour Island and it stays calm most of the time.
Walk north and you will discover two smaller beaches. The best way to get to them is to walk in the water. The northern most one is better, so press on. There are a few shady spots along the shore.