2) Panari Island, Okinawa, Japan
This quiet, largely uninhabited island is really comprised of two smaller islands, Kamiji and Shimoji. Also known as Aragusuku Island, this is the site of one of the largest living coral reefs in Asia. The waters are breathtakingly clear, and will offer you one of the most memorable diving experiences of your life. Most travel blogs advise that you hire a local tour guide to direct you to the best locations, as the prevailing conditions, such as the wind and tide, are important. One local islander, Kuroki-san, offers a touring service for small groups; and he promises to find divers and snorkelers the clearest waters in Sekisei lagoon, where sea turtles, manta rays, and the glorious colors of a thriving coral system await you. The island of Shimoji, with its population of around 10 people, will captivate you as you walk on its white sandy beaches, and marvel at its flawlessness.