Chumphon Pinnacle is the most famous and best dive site at Koh Tao, located about 12 km northwest of the island. It consists of a massive underwater granite pinnacle rising from 40m depth to 14m below the surface. The site is renowned for large marine life including whale sharks (especially March to May), giant barracuda schools, batfish, and sea snakes. Visibility can reach up to 30 meters. Recommended for advanced divers only due to currents and depth.