Sail Rock, also known as Hin Bai, located in the Gulf of Thailand between Koh Phangan and Koh Tao. Extending approximately 10 meters above the water's surface, the true allure of Sail Rock resides beneath, marking it as the largest underwater rock formation in the Gulf of Thailand. Sail Rock provides the best wall dive in the Gulf of Thailand and boasts a hollow channel called The Chimney inside the rock, so a scuba diver can swim downward vertically. Sail Rock is a dive location where sightings of the Whale Shark are more common. It is also a home to many thousand different species such as Barracudas, Queenfish, Mackerels, Batfish, Bannerfish, Groupers, and many more