Millerton Settlement, Bahamas offers 1 beach perfect for sunbathing, surfing, swimming, and more. Millerton Settlement, Long Island, Bahamas, is known for Dean's Blue Hole, one of the world's deepest underwater sinkholes. The best time to travel to Millerton Settlement, Bahamas, is from December to April, with average air temperatures around 75-85°F (24-29°C) and water temperatures about 75-80°F (24-27°C). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!