In total, the Bahamas include around seven hundred islands, no more than thirty of which are inhabited, as well as smaller cays (pronounced "keys") and rocks – an impressive arc stretching from just beyond the Atlantic coast of Florida to the outlying waters of Cuba, where Great Inagua lies only sixty miles offshore. Although deeper oceanic troughs surround some of the islands, most are encircled by shallow, crystalline water that reflects a light turquoise hue during the day and glows with purple luminescence at night. This combination of shallow and deep water makes diving and snorkelling both challenging and intriguing, with numerous reefs waiting to be explored just beyond the shores of the gorgeous, uncrowded beaches.