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Thailand’s Best Dive Sites

Having dived in Thailand for many years, I thought it was high time I weighed in with my list of the best dive sites in Thailand.  Hopefully, this will make your decision easier when you head to the Land of Smiles for your next dive holiday.

On The East

Mainland Thailand divides the Gulf of Thailand to the east side and the Andaman Sea on the west. Both very different diving environments have their own positive aspects for scuba diving.

The Gulf of Thailand

Koh Nangyuan | Koh Tao | Infinite Blue Dive Travel

The Gulf of Thailand is generally very calm, is comparatively shallow and sandy, and does not get as much tidal wash due to its protected nature. This means the waters are not as nutrient-laden as the west coast, and the substrate is not as suitable for coral reefs to develop. That said, there is a couple of great pinnacle dives in the gulf, where rock rises from the sea floor, and has become the home for coral and magnets for marine life, especially some large megafauna such as whale sharks. Incidentally, this is where I began my diving career in the Gulf of Thailand, hoping to dive with one of the largest marine mammals.

The upside to the Gulf’s marine environment is that it is a fantastic place to learn to scuba dive or to upgrade your diving certification. Hence, the islands in the region host numerous scuba diving shops and produce some of the world’s greatest numbers of scuba certifications per year. The islands of Koh Tao, Koh Samui, and Koh Phangan, provide a seemingly endless amount of choice, quality, and pricing when it comes to diving education. How to navigate dive education in the Gulf of Thailand is a subject for another time.

Where is the Best Place to Dive in the Gulf of Thailand?

Gulf of Thailand

Whether you have arrived in the gulf looking to do a PADI or SSI course, perhaps freediving, tech diving, or maybe fun diving, you will want to know the best places to visit. Here is a small list to help you out.

Chumphon Pinnacle: Chumphon Pinnacle consists of several main rocky outcrops and a couple more outlying rocky areas. Approximately 45 minutes on the dive boat out from Koh Tao, the top of the pinnacle has three boat moorings and is roughly 33ft (10 meters) from the surface. The greatest depth on the sand will take you to about 110ft (34 meters), with some wiley dive guides searching for something to show you further out at 40.

The pinnacles are covered in soft corals and anemones, while the deeper areas are home to healthy hard coral and sponges. Schools of batfish and pelagics, such as Barracuda and Snapper, can be seen. The show’s stars here, though, are the bull sharks that swim around the base of the pinnacles and the whale sharks that appear to have made Chumphon a stop-over in their migratory path.

Sail Rock: Sail Rock is another rocky pinnacle around an hour and a half by dive boat from Koh Tao or a very short one from Koh Samui, and competes with Chumphon Pinnacle as the best dive site in the Gulf of Thailand. Similar to Chumphon Pinnacle in many ways, this dive site also sports a chimney that you descend down, and pop out at different depths. Schools of Pelagics visit Sail Rock, as do whale sharks as they navigate the gulf.

On the West (Andaman Sea)

The west coast of Thailand is fringed by the Andaman Sea, which runs into the Indian Ocean, and hence is packed with loads of lovely nutrients swirling up from the depths. There are also considerably larger numbers of small islands, islets, and rocky outcrops in the waters, giving corals a better place to take hold and home marine life, attracting outer reef dwellers.

The Best Places to Dive on the West Coast of Thailand

The Phinisi With Sails Up | Infinite Blue Dive Travel

The diving on the west coast is usually divided into the south, the Similan Islands, in the middle, and the north, the Surin Marine Park, which is close to the border with Burma. Several liveaboards focus on these areas, and some connect them to create extended itineraries. When the Similan and Surin Marine Parks are closed between May and October, several dive boats will run trips focusing just on the south.

The South

The two highlights of diving in the south of the west coast of Thailand would have to be the dive sites Hin Daeng (Red Rock) and Hin Muang (Purple Rock).

Hin Daeng: About 40 nautical miles south of the world-renowned Koh Phi Phi island, Hin Daeng is a submerged rocky pinnacle that deserves its title as one of the best dive sites in Thailand. Covered in soft corals, the site is a magnet for schooling pelagics. Friendly Leopard sharks can be spotted here, as can whale sharks and huge manta rays.

Hin Muang: Just a stone’s throw away from Hin Daeng is Hin Muang. This site is also a rocky ridge that descends into the depths, but in the shallower regions is covered in swathes of soft purple corals, hence the name. You should keep an eye open for the same large marine life as Hin Daeng when diving here.

I have often been rewarded with manta ray encounters when diving at these sites. I haven’t been lucky enough to see whale sharks here, but the area’s beauty more than makes up for it.

Ao Nang Thailand

Koh Phi Phi

Moving north, just outside Koh Phi Phi, are two dive sites that often dived on day trips out of Phuket.

Koh Bida Nok: This site is probably the best site around Koh Phi Phi. Stunning karst limestone outcrops jut upwards, covered in sporadic tropical foliage, and the dive site lies around its base. You will be treated to gorgeous soft corals, sea fans, and hard corals here. Occasionally, reef and leopard sharks can be spotted, as can turtles, snappers, and schools of barracuda.

Koh Phi Phi Thailand

Koh Bida Nai: This small islet is the sister to Koh Bida Nok, which is nearby. The site has the same type of marine life seen at Bida Nok, but the water can be a little rougher, and the bottom descends deeper. There is a large swim through here and a nice coral-encrusted wall.

Central, Similan Islands

The central region of the west coast encompasses the Similan Islands, which are a favoured spot for live-aboard dive trips and even some day trips that make the speedboat ride out from Khao Lak.

This group of islands was a very popular dive destination before falling out of popularity a little when Indonesia became more accessible. However, many dive sites were closed for years, and stricter environmental practices were implemented. Since then, the marine environment has been recovering nicely, and dive sites have been reopened.

Shark Fin Reef & Boulder City: Two of the most southern sites dived in the Similan chain. These amazing sites offer an incredible, sublime landscape that can be breathtaking when dived with a bit of a current in good visibility. A huge granite ridge with cities of boulders strewn across the sand, on which grow remarkable gorgonian sea fans. Looking out into the blue, you have the chance to spot schooling pelagics, manta rays, and leopard sharks.

Best dive sites in Thailand | Similan Marine Park | Infinite Blue Dive Travel

Anita’s Reef & East of Eden: These two dive sites are the jewels in the crown of coral dives in Thailand. Both have stunning coral bommies covered in hard and soft corals nestled amongst large Gorgonian sea fans. The rest of the reefs are filled with rocks protruding from the white sand and encrusted with corals of all varieties. Here you will spot loads of reef fish, moray eels, and occasional sharks. These two sites are best dived with a bit of a current so that you can enjoy the whole gorgeous spectacle.

Elephant Head Rock, Elephant Head Pinnacle & Deep Six: These are three more absolutely cracking boulder and pinnacle dives that provide caverns and swim-throughs galore. Amongst the boulders, you will find a myriad of life. Elephant Head Pinnacle is one of my favorite dives in Thailand.

It is a bit harder to find, and deeper, and most dive boats will not go there. Situated close to the main dive site of Elephant Head Rock, you will need to use a depth finder to spot the top of the pinnacle about 33ft (11 meters) below the surface, as it is not marked in any way.

A negative entry in, and down you go through passages and swim-throughs until you exit into something like an arena underwater. If you are lucky, there will be reef sharks swimming around and schools of trevally hunting. This dive site is not for the faint of heart, and you must keep a close eye on your no-deco limit.

Christmas Point & North Point: These two dive sites are located north of the Similan Island chain. Christmas Point is a long reef and boulder dive that can yield stunning underwater seascapes, beautiful corals, leopard sharks, and schooling pelagics. I recall a great encounter with a mammoth school of pick handle barracuda here. North Point, the topmost dive site of the Similans, is a rocky outcrop with swim-throughs and passages covered in soft corals and sea fans. Closer to shore are fields of staghorn corals where a turtle encounter or two is common.

The North

Best dive sites in Thailand | The Junk Liveaboard Thailand | Infinite Blue Dive TravelHeading north from island nine, the Similan Islands are named in numbers from 1 – 9, you will arrive, after about an hour and a half’s sailing, to the first of the northern dive sites, Koh Bon. The north comprises Koh Bon, Koh Tachai, and then the Surin Marine Park, which runs along the border with Burma.

Koh Bon & Koh Bon Pinnacle: This is the last dive site I dived while running a liveaboard on the west coast, and it remains one of my favourites. Koh Bon is a horseshoe-shaped island with a hole in it through which you can view the outer side of the island. A good colleague used to joke with divers that the navy blew a hole through it so the Thai princess could see what was happening outside the sheltered bay.

Koh Bon is the place to see manta rays in Thailand. They come here to several cleaning stations that are located along the point and the hard coral reef on the outer side of the island. They are absolutely stunning creatures that don’t seem to pay much mind to divers, sometimes even choosing to play in your bubbles.

Koh Bon Pinnacle is a dive site located on the outside of Koh Bon, about 100 or meters out in the sea. Sometimes, there is a marker buoy and mooring line on the top, although sometimes this has come free. You may have guessed this is another less often-dived site. With a quick negative entry, you need to swim down and hide out of the current behind the pinnacle. You can choose to do this dive, starting deep and slowly making your way up the pinnacle, keeping in mind that the top is about 11-14 metres from the surface, so your safety stop will likely be in the blue.

If visibility is good and the current is correct, you may be able to drift all the way to the main island, check out manta rays on the point, and then finish your dive in the bay. This makes for an absolutely incredible dive.

Koh Tachai Pinnacle: Called twin peaks due to this dive site consisting of two submerged pinnacles, joined in the middle by a relatively shallow expanse of rock and dropping away off the sides. Koh Tachai is an incredible dive site, when the current is running, which is often, you can see huge schools of trevally darting around hunting between the pinnacles. This dive site is a well-known site for encounters with manta rays, and whale sharks. I was lucky enough to see both at once during a safety stop, when I dived there last.

The current can be very strong here, so make sure you are comfortable with that. The current though, brings the fish 😉

Richelieu Rock: Richelieu Rock is perhaps Thailand’s most well-known dive site, and for a good reason. This horseshoe-shaped rock, which sits close to the Burmese border, seems to act as a magnet for all surrounding marine life. This site is quite a distance out from larger land masses, so is completely exposed. This makes it trickier to get to and will mean your diving time will be limited. Usually, you can get two dives in here, and they are well worth it.

Here, you should see loads of different schools of pelagics, coupled with the chance of manta and whale sharks. That said, the stars of the show here, for me, are the cuttlefish, which you can find, often in pairs, all around the dive site. They pulse and glow in a rainbow of colours, communicating to their partners as they make their way around the coral outcrops and the base of the rock.

How to Plan Your Thai Diving Holiday

Best dive sites in Thailand | West coastIf you plan on heading to the Gulf of Thailand, perhaps to one of the islands Koh Tao, Koh Samui, or Koh Phangan, then your diving will be very easy to arrange with one of the many dive shops.

If you plan on experiencing the bulk of the best diving in Thailand, you will be heading to the Andaman Sea. By far the most convenient, and in some cases, the only way to scuba the sites mentioned above is by dive liveaboard. These will depart from Chalong Harbour in Phuket or Tap Lamu Pier, about an hour’s drive north of Phuket airport.

Here are our preferred dive liveaboards in Thailand.


To wrap it up

Thailand has some great dive locations and is suited for all levels of diving. There are two very distinct dive experiences to be had, either in the Gulf of Thailand or on the west coast in the Andaman Sea. Whichever you choose, you are going to have an awesome time. Thailand is a beautiful country to visit, and there are some great fishy experiences to be had.

We have been diving in Thailand for over two decades now, so don’t hesitate to get in touch for advice on planning your inclusive dive holiday here.



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