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The Best Dive Sites in the Gulf of Thailand

Gulf of Thailand best dive sites

Whale Shark (photo: Big Blue Diving)

While some argue Thailand’s finest diving is found around the Andaman Sea (West Coast), I beg to differ for a moment.

Phuket and Krabi can get extremely crowded, with significant amounts of young partiers year-round.

Moreover? Diving the Andamans is much more expensive than anywhere else in the region.

In my opinion, the East Coast islands feel cozier and more charming–particularly Koh Tao–in the summer (June-July).

Crowds never reach the unbearable levels of Phuket or Koh Phi Phi around that time (except perhaps Haad Rin during Koh Phangan’s Full Moon Party).

For these reasons, I recommend you take in the best dive sites in the Gulf of Thailand, sprinkled throughout the Samui Archipelago and Koh Chang. Below, my top five!

Chumphon Pinnacle

Like a roll of the dice, a dream dive site can be night and day, depending on weather and just plain luck. This was my experience at Chumphon Pinnacle.

A storm had hit days before my arrival, so sand had been stirred up, and Chumphon wasn’t all that on my first dive. My dive masters at Crystal Dive were horrified:

A good day in Chumphon will change your life. Give it another chance.

During my three weeks in Koh Tao, I did three to four immersions at the most acclaimed dive site on the island.

On my last day, the video you watched above happened. Wow.

Needless to say, you can’t miss this dive site! With up to 30 meters visibility, Chumphon Pinnacle is what a diver’s wet dreams are made of.

While the more chill, yet still an excellent diving season in Koh Tao is between June and July, you want to be there between March-April or September-October to increase your chances of swimming with whale sharks.

Coral at Sail Rock

Coral at Sail Rock (photo: Ryan Lackey)

Sail Rock

Locally known as Hin Bai, Sail Rock is one of Thailand's top wall dives according to PADI. I went on a day trip from Koh Tao via Big Blue Diving and enjoyed two fantastic immersions.

Gigantic groupers, massive schools of fusilier, many tunas, and even exotic critters such as painted shrimp, reef crabs, and nudibranch sprinkle the lively wall.

Ang Thong National Park (photo: Steve Jurvetson)

Ang Thong National Park (photo: Steve Jurvetson)

Ang Thong National Marine Park

If you are based out of Koh Samui or Koh Phangan, a day trip to Ang Thong is a must. In two or three dives you’ll be able to cover the best this national park has to offer.

Better yet? Since most sites are sheltered and shallow, this is an excellent spot for divers of all levels and even snorkelers.

With a good average dive depth of 15-18 meters, though, you'll see everything from staghorn corals and sea fans; large groupers and red snappers; shoals of fusiliers and rabbit fish; to even fun swim-throughs and caverns.

Most popular stops include Koh Wao, Hin Yippon, and Koh Wao Lek.

Want to visit Ang Thong? Book your Koh Phangan hostel here

Gulf of Thailand diving attractions

Baby Turtle (photo: Crystal Dive Resort)

Koh Nangyuan Pinnacle and Japanese Gardens

Koh Nangyuan is that picturesque island with a triple-sided beach you see in almost every Koh Tao advertisement.

Red Rock (also known as Nangyuan Pinnacle) will have you swimming through some amazing caves and over little sea mountains; in addition to spotting giant clams, barracudas, trevally, and sea urchins. One of my most fun dives around Koh Tao for sure.

Not far away are the Japanese Gardens, easily combined with a trip to the aforementioned pinnacle.

Excellent for both divers and snorkelers, this shallow site is home to an outstanding variety of life, including several types of coral, shoals of tropical fish, and even Hawksbill turtles.

Gulf of Thailand best diving

Shipwreck (screenshot by Tawan Buasuwan, YouTube)

HTMS Chang

After more than two decades sailing through several continents during World War II and the Korean War, the USS Lincoln County was decommissioned and later sank by Koh Chang Island.

Planning to visit Koh Chang? Book your hostel here

Known as HTMS Chang since its handover to the Royal Thai Navy in the 60s, this shipwreck is one of the finest artificial reefs in Thailand. Swim through its briefing rooms and cabins while being engulfed by a variety of underwater creatures. Top-notch!


Special thanks to Crystal Dive Resort and Big Blue Diving for the photos and complimentary dives. The Gulf of Thailand best dive sites were chosen by the author (a PADI-certified Rescue Diver, 90+ logged immersions), however. Selections were based on several interviews with diving experts and her honest opinion. 

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