Cotton Tree Bay, Cayman Islands offers 2 beaches perfect for sunbathing, surfing, swimming, and more. Tregastel is known for its stunning Pink Granite Coast and the Tregastel Marine Aquarium. The best time to travel to Cotton Tree Bay, Cayman Islands, is between March and June, when the average air temperature is around 82°F (28°C) and the water temperature is approximately 80°F (27°C). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!