9 Best Dive Sites in Koh Samui

Koh Tao (Turtle Island) lies 70 km north of Koh Samui. There are numerous dive sites in and around the island, which is a mini-tropical paradise offering jungle walks and white sandy beaches.

Here, the water visibility ranges from 15-30 metres. It includes popular dive spots like Chumporn and Southwest Pinnacles, Nang Yuan, Green Rock, White Rock, and Red Rock. The waters around Koh Tao are home to an abundant range of marine life, including barracuda, tuna, snapper and sea turtles.

Chumporn Pinnacles is one of the most challenging dive sites in Koh Samu. It occasionally has strong currents and depths of 10-35 metres. True to its name, this dive site indeed consists of fascinating submerged pinnacles.

The highest of these rocks is approximately 16 metres below the surface. Chumporn allows you to swim with man-sized groupers and other large pelagic fish, including schools of barracuda, tuna and mackerel.

Green Rock is a dive site in Koh Samui that provides a good selection of swim-through opportunities in depths of 4-25 metres. The rock consists of large archways, caverns, caves and crevices.

Common sightings include harlequin sweetlips, blue-ringed angelfish and moray eels. It's possible to spot whitetip reef sharks when diving in Green Rock. Large groupers, schools of yellowtail, and blue and yellow fusiliers can be found further out in deeper water.

Hin Wong is a large and varied site east of Koh Tao, with depths ranging from 10-30 metres. Unfortunately, the only shortcoming of the site is the unpredictable water visibility, which cannot be assured at all times.

Nevertheless, the site abounds with delicate sea fans and spiralling wire coral. It's also home to many types of fish, including groupers, filefish, and snapper. If you are lucky and keep your distance, you may even see turtles feeding around the reef system.

Samran Pinnacles is a dive site that tends to attract advanced divers in Koh Samui. Here, the water is deeper and currents are much stronger than most sites in the Gulf of Thailand. The rocks are submerged in 12 metres of water and attract large schools of jackfish (bigger varieties), trevally, and giant barracudas.

Southwest Pinnacles consist of 3 rock formations that range from 4-30 metres below the surface, representing a series of short wall dives. At the top of the pinnacles are blankets of underwater plant life in an array of colours.

Between the rocks, you can see many bushy black coral sea whips and gorgonian sea fans. Leopard sharks are often spotted in the Southwest Pinnacles, and it's even possible to meet a whale shark. Most of the time, the dive site has groupers, scribbled filefish, masked porcupine fish, yellowtail, barracuda, and snapper.

White Rock is a Koh Samui dive site that explores 2 submerged pinnacles, only 2 metres above the surface but extends between 18-22 meters underwater. Schools of butterflyfish and angelfish dominate the area. 

Colonies of staghorn corals attract breams and damsels to make their homes in White Rock. On any given dive, look out for sea snakes, turtles, morays and blue spotted stingrays. It's possible to encounter White Rock's resident titan triggerfish, which are territorial by nature.

Sail Rock is an internationally renowned dive site north of Koh Samui, between Koh Tao and Koh Phangan. Although only 15 metres above the water, the structure extends 40 metres below the surface. Its main attraction is a naturally formed, 15-metre high underwater dive wall (or chimney). Divers can ascend from 18 metres up the chimney wall to the surface, making this a unique diving experience. 

Visibility is usually excellent, at around 30 metres. The chimney has small holes housing white-eyed and yellow margin moray eels and sea anemones. Sightings of reef sharks and manta rays are also common, as are large schools of tuna, jacks, trevally and barracudas.  It's possible to encounter whale sharks if you're diving in Sail Rock during the winter months.

Koh Wao and Koh Yippon are the most popular dive sites in the Ang Thong National Marine Park. Both offer incredible swim-through experiences, not to mention encounters with caves, tunnels and passageways. Water visibility is around 15-25 metres. 

Ang Thong National Marine Park lies approximately 30 km northwest of Samui. It comprises 80 islands and offers some of the best diving in Thailand. The best time to visit this marine park is between September and January.