The famous island of Koh Phangan in the Surat Thani province of Thailand, is nestled between its equally popular neighbours, Koh Tao and Koh Samui. This world-class diving destination is unsurprisingly popular among the diving community. On land and underwater, you’ll encounter a diverse amount of exciting life, and with plenty for divers and non-divers to enjoy, it’s a great place to visit as part of your vacation. 

Koh Phangnan offers access to many of the best dive sites in the area, where colorful coral and fish thrive, and white sandy beaches with swaying palm trees line the coast. Towards the inner parts of the island, a dramatic backdrop of mountainous terrain covered in green fauna give the island magnificent postcard-worthy views wherever you’re situated.

The island is home to many reputable dive centers that make dive trips to sites not only nearby sites, but also those at neighbouring islands like Koh Tao and Samui, so there’s plenty of variety to be had for those who plan on diving for multiple days. 

As the diving is suitable for all skill levels, a variety of dive courses are conducted on the island, from absolute first-timer experiences and open water courses, to specialty courses and advanced courses. The majority of dive sites are easy, calm and suitable for entry-level divers, while seasoned divers will find them relaxing. What’s more, Koh Phangan is much quieter than its close neighbours, meaning dive sites are less crowded, and any courses that are undertaken are more likely to be on a more personal level, with smaller student groups.

Most dive sites on and around the island feature awesome topography with plenty of colorful fish, hard and soft corals, and fringing reefs overflowing with diverse marine life. The highlight of the region though, is the iconic Sail Rock dive site, which is accessible by boat from Koh Phangan in around 15 minutes by speedboat, and an hour on any other slower-moving vessel. This site is often cited as one of Thailand’s best, and many divers visit the area specifically to dive here.

Diving is possible all year round on Koh Phangan, as it is all around the Gulf of Thailand, thanks to its tropical climate and warm ocean temperatures no matter the season. The island usually experiences a dry season and a very wet season, though there are three notable seasons; the dry, cooler peak season that lasts from December until March, the wet low season, running from September to the end of November, and finally the hot season, which is in the middle in terms of tourist numbers and typically starts in April and ends in June.

Sea temperatures are comfortable all year round, normally lingering around 28°C-30°C (82°F-86°F). Air temperatures similarly rest around the same for most of the year, with the exception of the hot season, during which temperatures can sometimes soar into the 40s Celsius (low 100s Fahrenheit). 

Though diving is excellent throughout the year, the best time is said to be in the dry, cooler season, due to greater visibility underwater and comfortable water and air temperatures. Rainfall is also much lower, so diving trips are less likely to be interrupted by bad weather. In terms of marine life, it remains mostly unchanged throughout the seasons.

An array of exciting marine species can be encountered all around Koh Phangan. From tiny macro critters like nudibranchs, small crabs and shrimp, to schools of reef fish and larger creatures, like sea turtles, reef sharks and if you’re lucky, even the biggest fish in the ocean - the beloved whale shark. Though it’s never guaranteed, In March and April, there’s a good chance to bump into these spotted gentle giants at Sail Rock, so if you want to meet one, be sure to dive the site during this time.

The sites all around Koh Phangan and its nearby islands all host an abundant amount of life, almost too many species to list. An uncountable number of colorful reef fish thrive, such as anemonefish, schools of glistening batfish, cute pouting boxfish, dancing juvenile harlequin sweetlips, bannerfish, damselfish, filefish and many more. Curious cuttlefish and squid can also be seen, as can lots of vibrant starfish, lionfish and lots of impressively-sized grouper.

Blue-spotted stingrays can be found gliding across the sand, while schools of barracuda gaze hauntingly at passing divers. Observant divers may spot seahorses and octopus, and even camouflaged scorpionfish and stonefish. Sea turtles are also quite common, such as hawksbill and green sea turtle species. Shark lovers will love watching sharks fly across the reefs and sandy patches, including bull sharks and black tip reef sharks.

The must-visit site in this region is the famous Sail Rock (aka, Hin Bai) - a 30 meter/100 foot underwater pinnacle is often referred to as the best site in Thailand’s gulf, and hosts an enormous amount of fish and coral, and is said to be among the top sites in the country for whale shark-watching.

Koh Ma boasts a sloping reef dive boasting lots of colorful hard and soft coral, and an abundance of tropical marine species. Expect tons off reef fish, in addition to schools of razorfish and barracuda in the blue, while stingray and cuttlefish hang out on sandy patches.

Mae Haad offers easy diving on a beautiful fringing reef, where tons of life awaits, from nudibranch, cuttlefish and seahorses, to grouper and stingrays. This place truly has it all in terms of diversity.

Angthong Marine Park is also a must for any diver. It’s made up of 42 limestone islands, boasting interesting topography, including swim-throughs, caves, walls and sloping reefs. Soft and hard corals, fans and sponges alike thrive here, as does a wealth of marine critters, like barracuda, snapper, stingrays and plenty of reef fish.

Finally, the second most popular spot that closely rivals Sail Rock is Chumphon Pinnacle. Close to Koh Tao, this site is worth the journey, as it features impressive topography, including several dramatic pinnacles covered with life, boulders, and more. Divers will be astounded at the amount of life here, including schooling fish, lots of barracuda, grouper, batfish, a ton of reef fish and even leopard sharks on occasion.