The Best Diving in Thailand

Thailand in Pictures

Thailand has spectacular diving and picture-perfect beaches too. This Southeast Asian gem offers plenty and is one of the world’s most popular places to learn to dive. With the Gulf of Thailand on the east and the Andaman Sea on the west, there is so much to explore including fringing reefs, wrecks, drop-offs, and pinnacles.

Marine Life in Thailand         

Thailand’s marine life is colorful and teeming. Thousands of reef fish of every species congregate around the coral reefs and You’ll spot an array of butterflyfish, parrotfish, angelfish, wrasse, surgeonfish, triggerfish and trumpetfish. There are also plenty of Stonefish, scorpionfish, lionfish, sea snakes and morays. The bigger fish too will keep you entertained.  Barracuda, tuna, jacks and more. Manta and other rays, whale sharks, reef sharks too. Those who love macro life will find plenty of nudibranch, pipefish and other small, strange creatures.

Dive Conditions in Thailand          

Dive conditions in Thailand are very much dependent on the region you are diving in. The Andaman Sea offers more remote and challenging diving, great for liveaboards, whereas the Gulf of Thailand has calmer conditions and is great for novice divers, a first dive experience or a scuba course.

Liveaboards are popular for avid divers and the best way to see all that the region has to offer, especially in the Andaman Sea. There are dive resorts too that offer daily dive excursions by speed boat from the mainland or in the tourist areas.

Best Time to Dive in Thailand         

Thailand has a tropical climate. Visibility is about between 10m to 40m (33 to 131 ft.) depending on the season and location.

The two diving areas have different diving seasons.

Andaman Sea

In the Andaman Sea (Similan Islands, Surin Islands, Phuket, Koh Lanta, Koh Phi Phi) it’s mostly hot and humid all year round with the air temperature ranging from 25°C to 32°C (77 ℉ to 90 ℉) and water temperature around 29°C(84℉).

The rainy season runs from May to December and rainfall, usually at the end of the day) can be heavy from June to October. The dry and hot season runs from January to April which is the best time to dive in the Andaman Sea.

Gulf of Thailand

In the Gulf of Thailand, monsoon rains are experienced from November through to April. Visibility can be reduced by 30% after heavy rains. Tropical hot weather throughout the year with air temperatures from 28 °C to 32°C (82 to 90 ) and water temperature about 29 °C (84) all year round. The best time to dive is between May and September. May and June are best if you want to avoid the crowds.

Best Dive Sites in Thailand          

Andaman Sea

Similan Islands

The 9 tiny islands that make up this charming archipelago offer arguably the best diving in Thailand. They lie within the Mu Koh Similan Marine National Park and are best explored by liveaboard. Besides all the usual amazing marine life, often spotted here are leopard sharks, blacktip and white tip reef sharks. Throughout this island complex, enormous boulders are prominent both in and out of the water. Excellent for snorkeling too. 

Surin Islands

The Surin Islands is an archipelago of five islands in the Andaman Sea, 60 km from the Thai mainland. One of the world’s top ten dive sites, Richelieu Rock, is located here. This pinnacle is known for attracting big life like whale sharks, and manta rays in season (February to April) and is recommended for experienced divers because of the strong current. Other well-known sites here are Koh Torinla, Ko Chi, and Hin Gong.

Liveaboards often do a combined Similan and Surin Islands route. 


Phuket is the largest island in Thailand and offers some incredible resort diving. From here there is also access to Racha Yai and Racha Noi, smaller islands that offer great dive sites and where you may spot a manta ray along with all the other sea creatures. The Phi Phi islands are another great diving destination close by and offer caves and overhangs. Turtles and reef sharks also cruise these islands. Phuket is also an excellent place to learn to dive.

Hin Daeng and Hin Muang

Often cited as the best dive sites in Thailand, these sites attract the big life like whale sharks, grey sharks, leopard sharks, and mantas. Accessible from Koh Lanta, Phuket, Koh Phi Phi or via liveaboard, these sites will delight any diver.

Koh Lipe

If you like getting off the beaten track, this remote island is beautiful, peaceful and has fantastic diving. Some of the best-known dive sites here are 8 Mile Rock, Yong Hua Shipwreck, StingRay City, Hin Takorn Dukong, and Stonehenge.

Gulf of Thailand

The Gulf of Thailand offers an incredible array of diving and is a popular place to get your first dive certification.

Koh Chang

Koh Chang is all about pinnacles, gorgeous reefs, and wrecks. Part of the Koh Rang National Park, marine life is abundant here. Its picture-perfect white-sand beaches are another attractive feature for some post-dive relaxation. 

Koh Pangan

This island in southeastern Thailand offers the best access to the Gulf of Thailand’s best dive site, Sail Rock. Located between Koh Samui and Koh Tao, all of the region’s dive sites are accessible from this beautiful base. Other excellent sites here are Angthong Marine Park, Koh Ma, and Mae Haad.

Koh Samui

Koh Samui is an extremely popular tourist destination and a great place to base yourself if you want a holiday but access to diving too. The best dive sites here are actually on Koh Pangan and Koh Tao and boats leave daily for these sites.

Koh Tao

This small island has a number of great dive sites and is also one of the best places to learn to dive. The dive areas here have wonderful underwater scenery, calm conditions and you might even spot a passing pelagic or shark.


Pattaya has a range of great shipwrecks to dive, but also offers beautiful underwater reefs and marine life. There is even a submerged restaurant to dive! Dive the HTMS Kood, HTMS Khram and the Hardeep Wreck.

How to Get to Thailand

Bangkok’s Suvarnabhumi International Airport is the main airport in Thailand. Many international lines fly in here. There are also connecting domestic flights to most dive destinations.

Good to Know

Thailand is a fascinating country. Its cultural heritage and natural beauty offer much to the dive traveler. It is worth exploring the cultural sites and the islands as well as the underwater world. Thailand offers sandy beaches, tropical islands galore, an exciting nightlife, archaeological sites, museums, hill tribes, flora and incredible birdlife, palaces, Buddhist temples, and several World Heritage sites. 

Thai cuisine is also world-renowned.

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