The best snorkeling spots in Thailand

Thailand is the perfect destination for enjoying a wide array of underwater life and an easy-going vacation above the water.

The shallow water allows snorkelers to encounter anemonefish, angelfish, sea turtles, and blacktip sharks. Here are the preferred destinations for unforgettable snorkeling sessions in Thailand.

A pair of bannerfishin Koh Tao
A pair of Pennant coralfish in Tanote Bay, Koh Tao.

Snorkeling in the Gulf of Thailand

The Gulf of Thailand borders the eastern coast of the country. A dozen large granite islands, among the most visited in Thailand, are scattered along its coasts.

The best snorkeling spots in Koh Tao

Known as the “Turtle Island”, Koh Tao stands as the most renowned destination in Thailand, captivating both snorkelers and scuba divers alike.

Tanote Bay, Koh Tao
Tanote Bay, Koh Tao.

Don’t expect to see pristine, untouched corals on Koh Tao: the high numbers of visitors and episodes of coral bleaching have damaged the reefs. Some areas, however, are abundant with sea turtles, blacktip sharks, and multicolored reef fish.

Koh Tao features a dozen snorkeling spots, which can be visited during boat trips (a must-do activity on the island) or from the beach, although reaching the shore sometimes requires long walks through the jungle.

Green sea turtle in Shark Bay, Koh Tao
Shark Bay, nestled in the southern shores of Koh Tao, is frequently visited by green sea turtles.

Though many of the bays found in Koh Tao are perfect for snorkeling, one of the most revered of them all is Tanote Bay. Other popular locations on the island are Hin Wong Bay, Mango Bay, and Aow Leuk.

In the southern part of the island, Shark Bay is the place to go if you want to swim with blacktip sharks and green turtles, even though they are also common at other locations like Tanote Bay or Sai Daeng.

Nudibranch in Tanote Bay, Koh Tao
Tanote Bay is a good location to spot nudibranchs. Here, a Three-colored phyllidia.

The small island of Koh Nang Yuan, 650 yards/600 meters off the northwest coast of Koh Tao, is more worthwhile for its idyllic setting than for its seabed, which is very damaged.

The best snorkeling spots in Koh Phangan and Koh Samui

The neighboring islands of Koh Phangan and Koh Samui are located about 30 miles/50 kilometers south of Koh Tao. These two islands are famous for their vibrant nightlife, but some parts of them are very quiet and much less populated.

Scorpionfish in Koh Samui
A Painted scorpionfish noted at the Am Resort Taling Ngam house reef, Koh Samui.

In Koh Phangan, it is in Mae Haad, connected by a sandbank to the small island of Koh Ma, that the best snorkeling is found. Soft coral, sea kraits, turtles, and a plethora of fish species call the reef home. Following the coast towards the south, three other sites have good snorkeling opportunities: Salad Beach, Yao Beach, and Chao Phao Beach.

In Koh Samui, Chaweng Beach, Silver Beach, Coral Cove and Ao Phang Ka are the most popular snorkeling locations.

On these two islands, the sea can be rough in the most exposed locations, and underwater visibility can get bad, particularly in the rainy season.

Koh Phangan, Thailand
Koh Phangan.

If you stay for a few days in Koh Phang Ngan or Koh Samui, don’t miss the boat trip to the Angthong Marine National Park and its 42 tropical islands surrounded by turquoise water.

The best snorkeling spots in Koh Chang

Idyllic islands in the Gulf of Thailand, the Koh Chang archipelago is also a good snorkeling destination.

Although you can find decent snorkeling from the main island when the underwater visibility allows (you can try your chance at Kai Bae Beach or Lonely Beach), the best snorkeling is found on the small islands south of Koh Chang.

Cooperband butterflyfish in Koh Samui
A pair of Cooperband butterflyfish at Crystal Bay, Koh Samui.

Koh Rang National Park, which can be reached on day trips from Koh Chang, is a tropical paradise. Most snorkeling sessions during boat tours take place in Koh Rong, Koh Yak Lek, and on the islet facing Shrine Beach. Good snorkeling is found in Koh Mai too.

Elsewhere in the Gulf of Thailand, there is very good snorkeling on Koh Talu, one of the country’s few private islands, protected by a marine reserve. If you are staying in Pattaya, Koh Larn, Koh Khrok and Koh Sak are easy to reach with day trips.

Koh Haa (Five Islands)
Aerial view of Koh Haa (The Five Islands).

Snorkeling in the Andaman Sea

The Andaman Sea, which borders the western coast of Thailand, is home to some of the country’s most beautiful islands.

The best snorkeling spots in Koh Lanta National Park

Koh Lanta National Park includes part of the island of Koh Lanta, as well as several surrounding islands and islets. If the main island does not offer good snorkeling conditions, there are excellent sites in the surrounding area to visit on day trips.

Ocellaris aneonefish in a sea anemone in Koh Rok Nai
The Ocellaris anemonefish is a common sighting in Koh Rok. Here, in Koh Rok Yai.

The twin islands of Koh Rok Noi and Koh Rok Yai are both fringed with shallow reefs where you can see anemonefish, moray eels, angelfish, and other tropical fish.

The tiny archipelago of Koh Haa (The Five Islands) also hosts an abundance of marine life, particularly in the lagoon which connects the three central islands and at The Cathedral.

Other popular day tour destinations in the National Park include Koh Mai, Koh Gnu, Koh Ma and Koh Talabeng.

The best snorkeling spots in Koh Phi Phi

The Phi Phi Islands are a small archipelago off the coast of Krabi. This region mesmerizes visitors with its towering emerald hills, turquoise waters, and white sand beaches.

Banded sea krait at Monkey Beach, Koh Phi Phi
A visiting Yellow-lipped sea krait in Monkey Beach, Phi Phi Islands.

As one of the most popular tourist hotspots in Thailand, coral damage in the Phi Phi Islands reached a critical level at the end of the 2010s due to the booming tourism industry, leading to the complete closure of some popular islands.

The two main islands of the archipelago are Koh Phi Phi Don and Koh Phi Phi Leh, but only the first is inhabited.

On Koh Phi Phi Don, the most visited snorkeling locations are Monkey Beach (Yong Kasem Bay), a small jungle-fringed cove inhabited by a colony of crab-eating macaques, and Loh Lana Bay. All their corals, however, are destroyed.

Bamboo Island
Aerial view of Bamboo Island.

World-famous Maya Bay, on the neighboring island of Koh Phi Phi Leh, is the jewel in the crown of the Phi Phi Islands. The site reopened in 2023 after four years and the marine life – in particular the blacktip sharks- has returned to Maya Bay, but snorkeling and swimming remain prohibited.

Boats therefore take day trippers for snorkeling in the neighboring Pi Leh Bay, which mainly features coral debris-covered seabed.

Around the two Phi Phi islands, several islands and islets lend themselves to great snorkeling trips: Bamboo Island, entirely surrounded by a coral reef, and Mosquito Island (or Koh Yung), which is currently closed to visitors.

Powder blue tang in the Surin Islands
Reef life in the Surin Islands includes Powder blue tang and several species of butterflyfish.

The best snorkeling spots in the Surin Islands

This group of 5 small islands, located just 40 miles/65 kilometers off the coast of continental Thailand, seems like a slice of paradise. Within the boundaries of the Mu Ko Surin National Park, spanning a mere 10 miles/16 kilometers from north to south lies some of the most extraordinary snorkeling sites in the country.

The two main islands in the archipelago are Koh Surin Nuea to the north and Koh Surin Tai to the south. The Surin Islands are popular with day trippers from Phuket, Krabi, or Ao Nang, but if you want to better enjoy the place, opt for a liveaboard cruise instead. The National Park is closed during the rainy season, in general from mid-May to the end of October.

Koh nang Yuan, Koh Tao
Koh Nang Yuan, Koh Tao.

A dozen good snorkeling spots are scattered around the five Surin islands. If the reefs suffered several episodes of bleaching around twenty years ago, the reefs have now recovered and are among the most beautiful in Thailand.

Bigger animals like Manta rays or Whale Sharks can also be seen although sightings are less common.

The best snorkeling spots in the Similan Islands

60 miles/100 kilometers northwest of Phuket lies the Similan Marine National Park, a group of granite islands that includes the 9 islands of the Similan archipelago, as well as two islands located further north, Koh Bon and Koh Tachai.

Harlequin sweetlips at Lighthouse Reef, Koh Tao
A Harlequin sweetlips at Lighthouse Reef, Koh Tao.

The crystal-clear waters surrounding the Islands contribute to excellent visibility, allowing you to witness awe-inspiring creatures like nudibranchs, octopuses, reef fish, and sea turtles, for which the archipelago is an important nesting site.

Still off the beaten track twenty years ago, the Similan Islands are now visited by an increasing number of tourists.

There are many more snorkeling opportunities in the Andaman Sea, in particular in Koh Kradan, Koh Lipe, the Racha Islands (Koh Racha Noi and Koh Racha Yai), and the Hat Chao Mai Marine Park, near Koh Lanta.

The coral reef at Koh Nang Yuan
The coral reef at Koh Nang Yuan.

Which sea life is likely to be spotted by snorkelers in Thailand?

The degradation of coral reefs has continued for several decades in Thailand due to tourism and fishing activities. Even though some strict measures have been implemented to allow corals to recover, a large part of the country’s shallow reefs is still damaged in comparison with the Philippines or Indonesia, for example.

Despite the variable state of coral reefs, snorkeling in Thailand means a staggering array of marine life. The country’s reefs support thousands of fish and invertebrate species, hundreds of coral types, as well as sea turtles, sea snakes, blacktip reef sharks, whales, and manta rays.

Blacktip reef shark in Koh Tao
Shark Bay, in Koh Tao, is one of the best locations in Thailand to swim with Blacktip reef sharks.

As the country is sandwiched between two oceans, the marine life partly differs depending on whether you snorkel in the Andaman Sea, on the Indian Ocean side, or in the Gulf of Thailand, on the Pacific Ocean side.

Thailand is known as a reliable place to spot different species of anemonefish. On Koh Tao, Thailand’s diving Mecca, however, only two species are usually spotted: the Skunk clownfish, abundant at all locations, and the Saddleback clownfish, rarely seen at snorkeling depths. To encounter the famous Ocellaris clownfish, head towards the Phi Phi Islands or the Koh Lanta National Park instead.

A parrotfish among spinefoot in Tanote Bay
Parrotfish and Spinefoot are some of the most abundant fish in Thailand. Here, in Tanote Bay.

What is the best time of the year for snorkeling in Thailand?

With a water temperature on average around 82.4°F/28°C, Thailand is a year-round snorkeling destination.

There are two main seasons in Thailand: the dry season, from December to April, and the monsoon season, from May to November. With its sunny weather and mild temperatures, the dry season is the most suitable for snorkeling. During the rainy season, rain can last several days and boats remain at the dock due to poor sea conditions.

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