chiang dao
A Guide to Thailand’s Underwater Paradise

The kingdom’s most precious treasures lie hidden beneath the waves – so why not dive in?

Words: Phoowadon Duangmee

Looking for an underwater advernture in Thailand? World-famous for its stunning tropical beaches adorned with swaying coconut trees, Thailand also boasts a vast hidden treasure trove beneath the surface that makes it a scuba diver’s paradise. The country’s underwater world is unparalleled, offering a mesmerising spectacle for enthusiasts seeking extraordinary marine encounters. Picture yourself swimming alongside a whale shark in azure waters – just one among countless marvels awaiting sub-aquatic visitors to Thailand.

Many of the nation’s most renowned dive sites lie beneath the waves of the Andaman Sea off the west coast. The Similan Islands, consistently ranked among the world’s best diving destinations, teems with underwater adventures. Divers can weave through intricate coral gardens, their colours rivalling the brilliance of the sunlit surface, and find themselves gaping in awe as a whale shark glides gracefully by. This area is bursting with biodiversity, offering everything from playful reef fish to the awe-inspiring elegance of manta rays.

On the Gulf of Thailand side, Koh Tao (“Turtle Island”) stands out as a prized destination among both novice and seasoned divers. Explore vibrant coral reefs, hone your skills in crystal-clear waters, and encounter exotic species like giant grouper and friendly blacktip reef sharks.

From mysterious shipwrecks to eye-popping reefs, Thailand serves up an abundance of captivating locations for underwater exploration. Here are some of the best to kickstart your aquatic adventure.


Gulf of Thailand
Koh Chang

Koh Chang 

Renowned for its pristine beaches and lush jungles, Koh Chang attracts holidaymakers seeking to bask on tropical beaches beneath the sun. But for adventurous certified divers, Koh Chang is the ultimate destination for unparalleled underwater thrills in the Gulf of Thailand. The 52 islands of Mu Koh Chang National Park from an archipelago boasting some of the best scuba diving sites, ranging from stunning coral reefs to intriguing wrecks. The highlight of our trip was encounter with a majestic manta ray winging its way gracefully through the depths. Its impressive wingspan and gentle movements left us in awe as it effortlessly navigated the currents. Schools of barracuda and trevally added an element of excitement to the dive, creating a dynamic underwater symphony. For those captivated by wrecked and mystery, the HTMS Chang, a sunken warship, provided a unique and eerie backdrop for exploration. Covered in vibrant coral and teeming with marine life, the wreck offers a glimpse of the undewater world’s ability to reclaim and repurpose man-made structures. A whale shark is often spotted around the wreck, adding to the allure of this remarkable underwater landscape.


Koh Tao

Koh Tao 

Located just three hours’ boat ride from Samui, Koh Tao has emerged as a world-famous marine paradise with over 70 dive schools, attracting enthusiasts eager to learn scuba diving. This tranquil island showcases a breathtaking underwater landscape featuring technicolour coral reefs, intriguing rock formations, and a wealth of marine species. Dive sites such as Chumphon Pinnacle, Southwest Pinnacle, Sail Rock, Shark Island, White Rock, Green Rock, and the HTMS Sattakut Wreck create a rich tapestry of aquatic life, ensuring each dive is a unique and unforgettable experience. Chumphon Pinnacle, in particular, stands out as a must-visit site, celebrated for its thriving habitat of fish, shrimp, elegant white moral eels, and elusive crabs. Koh Tao’s diverse dive sites attract marine wonders like giant grouper, blue-spotted ribbontail rays, white-eyed moray eels, trevally, giant barracudas, and even whale sharks.

koh samui

Koh Samui

A top choice for scuba adventures, Koh Samui is an overlooked underwater jewel among Thailand’s popular holiday destinations. To match its bustling style, the island offers dive sites teeming with life and easily accessible via convenient day trips. Notable among them is Sail Rock, a prime example of Koh Samui’s proximity to some of Thailand’s finest underwater landscapes and a frequent haunt for majestic whale sharks. Beneath the azure waters, divers are treated to mesmerising spectacles – the graceful dance of barracudas, the serene glide of turtles, and the playful antics of jackfish. For macro photography enthusiasts, the intricate beauty of various nudibranchs and shrimp adds an extra layer of allure to the underwater experience. What sets scuba diving in Koh Samui apart is the consistent excellence of diving conditions year-round. Revel in the tranquil waters and relish unparalleled visibility. Whether you’re a veteran diver or a water baby, Koh Samui’s sub-aqua realm promises a remarkable adventure, blending accessibility, diverse marine life, and ideal diving conditions.



Pattaya hides a secret among its lively beaches and pulsating entertainment – four diving gems.

Koh Man Wichai impresses underwater enthusiasts with diverse marine life and exquisite coral formations. Within its dazzling coral gardens, schools of colourful fish engage in a kaleidoscopic dance. Boosting Pattaya’s allure for scuba divers is Koh Rin, celebrated for its ocean-floor adventures and thriving marine ecosystem. The island’s underwater landscape boasts breathtaking coral walls, providing a captivating backdrop for encounters with various reef fish and majestic sea turtles. Koh Rin stands as a testament to the rich biodiversity that thrives beneath the Gulf’s surface.

For history enthusiasts drawn to the mysterious of the deep, the wreck of HTMS Khram offers a compelling expedition. The sunken warship, adorned with marine life and an eerie ambiance, showcases the variety of Pattaya’s diving heritage. Meanwhile, Samae San, with its labyrinth of underwater caves and vibrant coral formations, completes the quartet of Pattaya’s exceptional dive sites.


Andaman Sea
similan island

Similan Islands

Renowned for incredible opportunities to encounter majestic mata rays and awe-inspiring whale sharks, the Similan Islands stand as a beacon for divers seeking out-of-the-ordinary experiences. These gentle giants swoop and glide through the depths, creating moments of sheer wonder for those fortunate enough to encounter their grace. Rising from the Andaman Sea, this archipelago of nine granite islands has earned a well-deserved reputation for crystal-clear waters, vibrant coral reefs, and diverse marine life. The Similans boast a diverse array of dive sites, each possessing its own unique charm and underwater wonders.

Richelieu Rock, a pinnacle of marine diversity, is a top choice for divers in search of vibrant coral gardens, seahorses, and elusive whale sharks.

Elephant Head Rock showcases stunning undersea landscapes of giant boulders and enticing swim-throughs, while Chirstmas Point is celebrated for its colourful soft coral formations and bustling marine life. Above the waves, the Similan Islands offer pristine white sandy beaches and lush landscapes, serving as a perfect complement to the exhilarating diving experiences.


koh lanta

Koh Lanta 

A hundred kilometres south of Phuket, Koh Lanta enchants holidaymakers with divine miles-long beaches and captivating sunsets. But for avid divers, grabbing a liveaboard from Phuket to this remote Andaman Sea island opens the door to thrilling encounters with giant manta rays and whale sharks. Hin Daeng and Hin Muang (“Red Rock” and “Purple Rock”) garner global acclaim as pristine and fascinating dive spots.

Rocky formations rise from the ocean floor, creating underwater mountains with vertical walls that beckon exploration of underwater canyons. The sheer scale of these structures is a mesmerising experience for many divers. Renowned for their rich marine biodiversity, these sites are carpeted with soft corals in shades of red and purple, adding a surreal beauty to the panorama. Home to diverse species such as manta rays, whale sharks and various other sharks, Hin Daeng and Hin Muang are iconic destinations for those seeking extraordinary underwater adventures.


phi phi island

Phi Phi Islands

The Andaman’s Phi Phi Islands attract divers from around the world with a rich array of undersea wonders. A standout site is Hin Dot, a submerged pinnacle renowned for hosting large schools of fish drawn from various species – nurse sharks, groupers, pufferfish, lionfish, squid, bearded scorpionfish, and a myriad of others. Hin Pae also captivates with its dramatic landscape of soft and hard corals that provide shelter for a marine cornucopia that includes crabs, lobsters, angelfish, groupers, snappers, and surgeonfish.

The King Cruiser wreck, a sunken passenger ferry, adds an element of mystery and adventure to the diving experience. Encrusted with corals and teeming with marine life, this underwater relic has evolved into a thriving artificial reef. Venturing to Koh Bida Noka unveils a marine paradise where encounters with leopard sharks, turtles, moray eels, and ghost pipefish are commonplace, and divers always have the hope of encountering elusive whale sharks and manta rays. Shark Point, aptly named, promises thrilling encounters with leopard sharks and the occasional appearance of majestic whale sharks.


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