Owen Island, Cayman Islands
However, the ultimate deserted beach in the Caymans is the uninhabited Owen Island, which sits about 200 yards off the southern side of Little Cayman. Owen Island can be reached by kayak or sailboat, although strong swimmers have been known to swim the distance.
The clear blue waters, almost deserted fine-sand beaches, and uninhabited landscapes make this as close to idyllic as most people can hope to get in the Caribbean.
For more secluded beaches go to:
http://www.mnn.com/lifestyle/eco-tourism/photos/8-best-secluded-beaches-in-north-america/owen-island-cayman-islands