The Mu Koh Similan National Marine Park consists of the nine Similan Islands, as well as Koh Tachai and Koh Bon, which are farther north. The diving around the Similan Islands is world class, with visibility of up to 120 feet; abundant blue, green, and purple coral; and rare marine life, such as the whale shark, the world's largest fish. In addition to sparkling, crystal-clear water, the Similan Islands also have ultrafine, powdery white-sand beaches and lush tropical forests. The National Park Service allows visitors to stay on the beaches of Koh Miang (Island 4) and Koh Similan (Island 8). If you plan to dive, contact a dive operator in Phuket or Khao Lak; there are no dive shops on the islands, though snorkeling gear is available for rent from the ranger stations.