Scuba diving is another activity that nurtures mindfulness—I like to call it underwater meditation. It brings a calming focus to the mind and breath, helping to cultivate a sense of inner peace. Diving isn’t just about exploring the depths of the ocean; it’s also about discovering the depth and clarity of your own mind.
Above water, Thailand dazzles with glittering temples, buzzing markets, sandy beaches, rugged rainforests, green paddy fields, lovely villages and more. But beneath the surface? That’s where the real magic happens.
Fringed by the Gulf of Thailand to the east and the Andaman Sea to the west, Thailand offers some of the most spectacular and diverse dive sites in the world – think coral gardens, dramatic drop-offs, tunnels, caverns, wrecks, and seamounts teeming with life. Whether you’re a beginner earning your first certification or a seasoned diver chasing whale sharks, Thailand promises something unforgettable.
Thanks to its tropical climate, diving is a year-round activity in Thailand. While water temperature remains moderate all year, the best time depends on where you dive: the Gulf of Thailand shines from May to September, while the Andaman Sea is at its finest from October to April.
Here are the highlights:
Mu Koh Similan (Similan Islands)
Location – Phang Nga – Boats depart from Khao Lak in Phang Nga and Phuket
Off the coast of Phang Nga, the Similan Islands are often hailed as one of the world’s top diving destinations. This archipelago consists of 11 islands covering a total area of 140 km², of which 26 km² is land (source: PADI). Giant granite boulders, vibrant hard and soft coral reefs, diverse marine life, and white sandy beaches create a diver’s paradise. The water is crystal clear, and the underwater terrain—ranging from gentle slopes to deep canyons—is breathtaking.
The nearest departure point is Khao Lak, about 1 to 1.5 hours by car from Phuket. Thanks to its proximity to the Similan Islands, it’s an ideal base for beginners to complete their Open Water course and then take day trips to one of the world’s best dive sites.
Mu Koh Surin (Surin Islands) and Richelieu Rocks
Location – Phang Nga – Boats depart from Khao Lak in Phang Nga
North from the Similan Islands, Surin Islands are an archipelago of 5 islands within Mu Ko Surin National Park, also in Phang Nga. The national park covers an area of 135 km² of which 76% is sea. There are several dive and snorkel sites around here, from gently sloping coral reefs, to granite boulder dive sites.
East of the Surin Islands lies Richelieu Rock, a majestic pinnacle that breaks the surface only at low tide and drops down to over 30 meters. This renowned dive site is home to a rich variety of marine life, including moray eels, colorful nudibranchs, cuttlefish, giant groupers, seahorses, lobsters, and more. Whale sharks are also frequently spotted here.
Mu Koh Phi Phi
Location – Krabi – Boats depart from Krabi and Phuket
While most visitors come for the iconic cliffs and turquoise lagoons, divers know that there are much more underwater. Vertical limestone walls plunge into the sea, home to soft coral gardens and sneaky critters like mantis shrimp and seahorses. Look out for blacktip reef sharks, turtles, and even whale sharks cruising through during plankton season.
Mu Koh Lanta
Location – Krabi – Boats depart from Krabi and Phuket
The waters around Mu Koh Lanta are home to some of Thailand’s top dive sites—Koh Ha, Koh Rok, Hin Daeng, and Hin Muang—all offering incredible marine life.
Part of Krabi Province, Mu Koh Lanta comprises two islands: Koh Lanta Yai, the more developed one, and Koh Lanta Noi, connected by a bridge. Most visitors come to Mu Koh Lanta by speedboat or minivan + car ferry, which runs daily from 6 AM to 10 PM. However, if you only want to dive, you can join a day tour or a liveaboard tour departing from Krabi or Phuket. There’s no need to get to Mu Koh Lanta.
Koh Tao and Koh Nang Yuan
Location – Surat Thani – Boats depart from Koh Tao, Koh Samui and Chumphon
Literally translated “Turtle Island,” Koh Tao is a diver’s rite of passage. Many get their Open Water certification here, thanks to the calm, crystal waters and affordable prices. But don’t be fooled by its popularity – this little island has serious underwater charm. Pinnacles covered in coral, sunken ships, and the occasional eagle ray or whale shark make every dive a new adventure.
If you are looking for marine conservation focused scuba diving on Koh Tao, check out Conservation Initiatives Koh Tao | Black Turtle Dive and New Heaven Reef Conservation Program. You can participate in the program for a day, a few days or longer.
Just a short boat ride from Koh Tao lies Koh Nang Yuan, a private island unlike any other. Picture this: three tiny islands linked by a stretch of soft white sand, surrounded by turquoise clear waters. That’s how I’d describe Koh Nang Yuan: breathtaking, serene, and utterly unforgettable.
Chumphon
Location – Chumphon – Boats depart from Chumphon and Koh Tao
Tucked away from the crowds, Chumphon Marine Park is a hidden gem for divers who like their reefs quiet and wild. Here, giant anemones sway over colorful rock formations, black corals cling to the sea floor, and frogfish play hide and seek. Whale sharks are regular visitors, and adventurous souls can explore caves, wrecks, and swim-throughs without the usual tourist buzz.
There are plenty of diving centres and diving schools in Thailand. It’s highly recommended to read reviews, contact for more information before making your booking. Below are just the ones I have been in contact with before:
Black Turtle Dive Koh Tao covering Koh Tao, Koh Nang Yuan, Chumphon
Duck’n Dive Koh Tao and Nang Yuan Dive Resort covering Koh Tao, Koh Nang Yuan and around
New Heaven Dive School Koh Tao covering Koh Tao, Koh Nang Yuan and around
Sea Bees Diving covering Mu Koh Similans, Mu Koh Phi Phi and around
Click here for more information about scuba diving sites in Thailand and here for regulations for divers and snorkellers.