Sail Rock

Sail Rock is a large granite rock formation rising about 15 metres out of the Gulf of Thailand, situated roughly halfway between Koh Phangan and Koh Samui, and is considered one of the most iconic dive sites in Thailand. The rock sits on the seafloor at around 30 metres depth, and because there is no other rock formation nearby, it acts as a natural gathering point for fish. Depths at the site range from 1 metre to around 40 metres, making it suitable for intermediate to advanced divers, with a 1–2 hour boat journey required to reach it.

The standout feature of Sail Rock is "The Chimney," a vertical swim-through that begins at approximately 5 metres and descends to around 20 metres, cutting through the main rock. Outside the chimney, the main rock can typically be circumnavigated several times in a single dive, with additional scattered rocks in the deeper sections further from the main formation. Water temperature runs between 27–30°C, and the site is diveable from March through October, with whale sharks most associated with the site during their seasonal visits.

Marine life at Sail Rock is defined by large schooling species and substantial pelagics. Inside and around the chimney, schools of batfish, barracuda, and thousands of bigeye trevally form dense aggregations. Giant groupers move through the deeper sections, and reef sharks are regularly encountered around the more distant rocks at depth. Fusiliers, jacks, and king mackerel are also present, and nudibranchs and shrimp species can be found for those looking more closely at the structure.