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    About Thailand

    Often referred to as the “Land of a Thousand Smiles,” Thailand offers joyous travel. Thailand liveaboards visit the Similan Islands, Koh Bon, Koh Tachai, and Richelieu Rock to the northwest of the resort island of Phuket, and Koh Phi Phi, Koh Ha, Hin Daeng and Hin Muang to the south, known as our Southern Islands.

    Thailand is blessed with two bountiful seas, the Andaman Sea and the Gulf of Thailand. Thailand sits between Cambodia, Laos, Burma, and Malaysia and is the one and only country in Southeast Asia to have never been colonized. The Kingdom is blessed with a remarkable history and culture, friendly natives who offer friendly service, beautiful national parks, a wide range of accommodation possibilities at every price level, and some of the most delicious and extraordinary cuisine in the world. The riches that Thailand’s oceans behold are a delight to those of us that have had the pleasure to dive here.

    It’s a Mai Pen Rai Kind of Country

    One of the first Thai phrases travelers learn is mai pen rai which literally translates to “it is nothing.” The phrase is used in the same ways that “never mind” or “that’s OK” are used in English. However, maipenrai means more than that; it is almost a philosophy that teaches one to disguise problems to keep one’s “public face” smiling and happy. It’s a phrase used for respect and politeness. For the visitor this attitude creates a feeling of burdens lifted. It makes you feel happy, content and cheerful because everyone around you is the same–or at least pretending to be. While exploring the country you’ll feel carefree, lighthearted and safe; you’ll feel maipenrai. No wonder so many of us expatriates have decided to stay, or that Thailand welcomes well over 45 million visitors every year. Your first trip is usually not your last.

    Liveaboard Diving in the Land of Smiles

    Thailand’s Andaman Sea is the perfect place for a diving holiday with our world-class diving, heavenly tropical islands and immaculate white sand beaches. With water visibility often exceeding 30m (100ft), an average ocean temperature of 28º to 32º C (82 to 90ºF), and uncommonly calm sea conditions, Thailand has some of the most comfortable and safe diving, cruising and sailing environments found anywhere in the world. We’re especially famous for manta rays and whale sharks which are fairly common on our waters.

    Liveaboard Diving in Andaman Sea

    Since Thailand’s southern isthmus divides two oceans, you’ll be heading south for diving. The best diving takes place along the southwestern shores around the resort island of Phuket. The Similan and Surin Islands Archipelagos are the top destinations because they offer the best diving. There is no other place in Thailand which offers the diversity of marine life or sheer amount of dive sites. This is a known fact and is not in dispute. The Andaman Sea is where you want to be. Thailand is also the diving gateway and departure point to Burma’s Mergui Archipelago and the Andaman Islands.

    Getting Here

    To get the best dive sites in the Andaman Sea, it is almost always necessary to travel overnight by liveaboard vessel. Although there are plenty of resorts in Thailand at her many islands and beach areas, the best diving is located far offshore and these are best reached by a type of vessel you can sleep on. Yes, some operators have speed boats to get you to some of these places, but the rides are long and bumpy and generally not safe. We don’t offer them, period. Liveaboards are the only way to get to the best destinations in the Andaman Sea. Trips range from three to 10-days. Prices are relatively low and value is extremely high.

    Phuket International Airport, the South’s Travel Hub

    Most of the dive boats leave from the ports in Phuket or just north of Phuket. There are dozens of daily flights into Phuket International Airport (HKT) from all over the world. We’re an hour from Bangkok and just over an hour from Singapore. We’re four hours from Hong Kong Jakarta, or Manila. We’re five hours from Dubai. Currently, we’re the third most popular island in the world.

    Infrastructure in Thailand is well-developed with a very strong tourism industry. Transportation between islands and cities is excellent. We have planes, trains, automobiles, ferries, buses, and in Bangkok, subways and sky trains. All of it is easily accessible and inexpensive.

    A visa is generally not required for a 30 days visit to Thailand. For some nationalities a Visa On Arrival (VOA) is required. Tourist visas for up to 60 days are easily obtained at a Thai Consulate. Longer stays are also possible. For current information Google your local Thai Consulate. Information is provided in your language.

    The Best Time to Visit

    The diving season for Thailand’s the Andaman Sea is from November to April each year when the northeast winds are balmy and mild. Generally we’re considered closed from May until September each year due to unpredictable weather. The Similan and Surin Islands are closed by law during this time.

    Thailand’s Liveaboards


    Popular Thailand Dive Sites

    About the Author


    John Williams has written, co-authored, or contributed to four diving guides on Thailand, the Mergui Archipelago, and the Andaman Islands. These are the award-winning Lonely Planet Diving & Snorkeling series, Periplus Editions Diving Southeast Asia, Asian Diver Scuba Guides and Singapore’s Times Edition Diving Thailand. He has lived in Phuket and dived in Thailand’s waters since 1987.


    The Similan Islands archipelago is by far the most beautiful group of dive sites that we have in Thailand and one of the best diving spots in Southeast Asia. The Similan Islands are located about one hundred kilometers northwest of Phuket. They feature nine granite islands covered in tropical jungle, washed by the clear blue Indian ocean and blessed with some of the world’s finest beaches. Similan comes from Malay fisherman who named it “The Nine Islands.” Similan is “nine” in Yawi, a South Thai-Malay dialect.


    The islands are identified by a name and a number, one through nine. The islands are part of the national park status and fully protected under Thai law. The National Park Authority maintains their presence on two of the islands: Koh Similan (Island 8) the largest, and Koh Miang (Island 4). There are basic bungalows and camping on Island 4.


    The West Coast offers fast-paced exhilarating diving as currents swirl around the huge granite boulders, some larger than the largest of houses. These smooth rounded boulders create formations, forming holes, and overhangs or swim-throughs underwater where divers can enjoy ducking and kicking through the openings. The drama of looking up through the clear water at these huge rocks is satisfaction enough for some divers, as there are very few places like this on earth. Growing on these boulders are some of the most colorful soft corals imaginable, in many places so thick that the rock is no longer visible. In the larger passages or channels between the boulders, the orange sea fans characteristic of Similan grow to three or four meters across, and are often so tightly bunched together they block passages.


    The East Coast once offered healthy coral down white sand slopes, but the coral bleaching event of 2010-2011 severely impacted these corals. Many of the eastern dive sites are closed to the public to allow them a full recovery. In a few areas, especially around Island 5 you’ll see what it looked like before and what it will look like again one day. You’ll be doing some of your dives on the east side of the islands for sure, but not as many as you once would.


    If you enjoy watching and photographing tropical fish, the Similan Islands are hard to beat for the sheer numbers and varieties of tropicals, especially lion fish and anemone fish. The Similans are not well-known for big fish-action, but we do see giant trevally, some Napoleon wrasse and turtles. Of course the most famous aquatic resident of Thailand, the leopard or zebra shark, makes his appearance on a regular basis. As the park becomes more and more protected from fishing, fish sizes are increasing. Overall, in my opinion, the reef fish are 20-30% larger on average than they were 30 years ago when I started diving here.


    We’ll also see white tip and black tip sharks, and a few times over the years we’ve seen schools of pseudo orcas or false killer whales. We get a lot of dolphins between the islands moving north and south. Enjoy the Similans for wild, unspoiled beaches, magnificent soft coral, prolific fish life, crystalline blue water and sensational underwater rock formations.

    Koh Bon is located about 20 km north of Similan Island 9 and features one of the few vertical walls in Thailand. The main dive site is on the southwestern point and has a step-down ridge that carries on to depths of over 45 meters. The eastern side of this ridge forms the wall and this is where most divers will enter the water and generally where the boats moor. The western side of the ridge is more of a gentle slope with coral bommies forming mushroom-like formations out of the finger corals. On the ridge itself, sea fans of different sizes, shapes and colors grow, and schooling fish swim in the current feeding. This is generally where most divers will sit most of the dive, hoping for a sighting of the manta rays which frequent this dive site. These creatures seem to travel from Bon to Tachai and back again.


    Leopard sharks are pretty common below the ridge on the sandy flats. Although the soft corals are not as high-profile as they are in the Similans, the colors of the corals are radically different and include shades of turquoise, yellow and blue, besides the more common pinks and purples. The colors are more pastel than the usual hard bright we see commonly other places.


    Rays will sometimes be found in the deeper areas at depths for more experienced divers. The Koh Bon ridge is full of individual and schooling fish and some overhangs have places for smaller creatures to hide, but this is more of a fish and coral dive than a critter dive. .


    Above the waterline there is a huge hole on the ridge and when a swell is running it pushes the water through the hole and the force of it makes white water below the surface making for a fun and exciting safety stop. Just don’t get too close to the surface if the swell is big.


    There is a pinnacle in the bay just to the north of the ridge. It’s a deep rock, but if you’re an experienced diver it’s worth the short bottom times you’ll get as it’s a very special site. Not all boats visit it and if currents are strong it’s not worth the effort. But, if the water is clear, you’re good with your breathing gas, and the current is slack, it’s a stunning rock. It looks like a monolithic temple built by some ancient culture.


    The rock runs along an almost east to west course, the taller of the two pinnacles comes up to about 18 meters and the other pinnacle comes only up to about 24 meters. The sandy areas around the rock are well over 45 m so beyond the range of most scuba divers. However, when the visibility is good you see all the way around the rock. Leopard sharks hang here, but it’s also a good place to see smaller critters hiding in the rock. The pinnacle is fairly close to the main ridge and it’s possible to swim to the ridge, though there is little reason to do so.

    Twenty-five kilometers north of Koh Bon, Koh Tachai has an offshore underwater ridge that runs perpendicular to the island. Known as “Twin Peaks” this is considered to be one of the finest dives in Thailand and is famous as a place to see not only the more common species of corals, fans and tropical fish, but larger animals such as rays, leopard sharks, nurse sharks and hawks bill turtles. Whale sharks and manta rays make an appearance on a regular basis.


    A ridge runs between the two pinnacles, though the eastern rock is the one most people dive as there are boat moorings making it easier for divers to descend in a strong current. If you have the gas and the current is not too strong, it’s worthwhile swimming to the other rock which comes up a bit shallower. However, most of the time the current runs perpendicular to the ridge making a long swim tiring. It’s heaven for the fish, though; they hunt and dart around, coming very close to divers, making the diving here about as exciting as it gets.


    A ridge runs between the two pinnacles, though the eastern rock is the one most people dive as there are boat moorings making it easier for divers to descend in a strong current. If you have the gas and the current is not too strong, it’s worthwhile swimming to the other rock which comes up a bit shallower. However, most of the time the current runs perpendicular to the ridge making a long swim tiring. It’s heaven for the fish, though; they hunt and dart around, coming very close to divers, making the diving here about as exciting as it gets.


    Koh Tachai also boasts a breathtaking sandy beach on its northeastern shore; It’s a popular anchorage when northeast winds have calmed down in March and April. The beach is one of the prettiest anywhere though it’s not always open.


    Some boats offer night dives on the western part of the island in a small bay or in front of the beach weather permitting. The main ridge is generally too deep and the currents too strong for reasonable and safe night diving.

    Richelieu has become famous as one of the best places in the world for swimming with our gentle giant, the whale shark. Encounters with the largest of all fish are rare almost any place in the world. But for some reason, Richelieu attracts more than its fair share. Swimming with such a large animal known to grow to lengths of 20 meters or more has to be a high point for any diver. Sightings are up and down, but the past two or three years we’ve seen numbers like we did way back in the 1990s. This is encouraging. When they are seen, you generally get a really good look since you’re diving in clear water, and they swim close to the rock. It’s like a parade, a happy parade.


    Nearly every imaginable variety of bony fish is found here, including many species of butterfly fish, wrasse, damsel fish, lion fish and a host of other reef dwellers. Among the most abundant species are scorpion fish, which are amazingly adept at blending in with their surroundings. Be especially careful where you put your hands, because many things that look like rocks are not really rocks! A number of eel species live here as well, including giant, white-mouth, fimbriated, snowflake, bar-tail and zebra morays. Schooling fish like fusiliers and snapper are also prevalent, in addition to open water predators like rainbow runners, mackerel, and barracudas. One schooling fish deserves special mention–a huge school of bigeye jacks can often be seen on the up-current side of the rock, where they often circle divers en masse, creating a living maelstrom of fish. Schooling chevron barracudas are seen almost all the time.


    Divemasters are now quite good at spotting ghost pipefish, Harlequin shrimp, and tiger-tailed seahorses–if you don’t see something weird here you just aren’t paying attention. Cuttlefish hover around, usually in the autumn, but very often at other times of the year as well. Octopus is common, and lionfish as well as different kinds of anemone fish are easily spotted.
    Richelieu Rock is a world-class dive site, and if you don’t like diving here, you simply don’t like diving! You can dive here over and over and see something new. The currents change constantly, and it’s not always an easy dive. But, if you listen to your dive guide and his or her briefing, you can learn how to hide from the currents and have a very enjoyable dive all the time. Many boats will spend the entire day here so you can get a full appreciation of the variety of conditions and marine life at this fantastic dive site.


    Note:Recently there have been postings (even on PADI’s website) that Richelieu Rock was named by Jacques Cousteau’s team when they were filming in Thailand and the Andaman Islands in 1988 and 1989. However, Richelieu Rock was named long before Mr Cousteau visited these waters so this story is simply inaccurate no matter how romantic it sounds. There were European explorers all over Southeast Asia from the 15th to 19th centuries and many European names exist for islands and rocks in Thailand as well as in the Mergui (Myeik) Archipelago in Burma. By the way, Cousteau was denied permission to go to Burma when his team was here, but he did do a little-known film about the Andaman Islands called The Invisible Islands. It’s worth watching if you can find a copy.



    There are a few dive sites, mainly on the southern island (Surin Tai) which are popular with a number of boats and their guides. The key to having a good dive here is to have a very knowledgeable guide to show you the highlights. Every divemaster has his or her favorite. Just jumping in and swimming around is normally disappointing for most people. The snorkeling is fairly nice in the protected bays and the anchorages are wonderful. It’s right on the Burmese border so seeing Surin gives you a taste what the islands in Mergui are like.

    Koh Ha is a small group of islands almost directly west of Koh Lana. These tiny islands, separated by channels over 50 meters deep, jut straight out of the Andaman Sea. However, unlike at Phi Phi, the water here is ordinarily quite clear and visibility frequently exceeds 25 meters. The highlight of diving here is a series of caves, or caverns on the largest of the islands, Koh Ha Yai. The caves are safe to enter, even without a light, as the entrances are large and there is only one way in and one way out. The best part of entering these caves is that you can surface inside the island to view stalactites hanging down from the ceiling over 30 meters above the surface. The quality of light filtering through the water from the entrance is magical and often you can see big fish swimming back and forth in front of the entrance.
    The sole reason that diving has become world-class in Koh Lanta and Krabi are two pinnacles that lie approximately 25 km southwest of Koh Rok. Hin Daeng (red rock) and Hin Muang (purple rock) offers everything a diver could want, from dramatic walls and big fish action, to lush tropical underwater gardens.


    Leopard sharks are pretty common below the ridge on the sandy flats. Although the soft corals are not as high-profile as they are in the Similans, the colors of the corals are radically different and include shades of turquoise, yellow and blue, besides the more common pinks and purples. The colors are more pastel than the usual hard bright we see commonly other places.


    Hin Daeng is easily found since it protrudes about three-meters above the surface. Although not very impressive topside, underwater the rock is huge. The southern side descends straight down to over 60m (200ft) forming the most radical vertical drop in Thailand’s seas. The wall is dotted with light growths of soft corals and a few sea fans, but is otherwise devoid of life. On the eastern side where the slope is more gentle, two long ridges descend into the blue and if the currents are favorable it is possible to swim along these ridges down to 40 meters or more. Here the soft coral becomes more lush and tall, and huge schools of jacks sweep past the ridge, surrounding the diver with a shimmering wall of silver. Ascending to the shallows we see needle fish skip along the surface. Barracudas stalk their prey through the clear water. Swimming between the three large rocks that form the surface-view of Hin Daeng, large schools of fusiliers dart to and fro as if they are afraid of the water surging through the channels.

    Hin Muang, located just a few hundred meters from Hin Daeng, lies completely submerged. What surprised us the first time we explored the rock was the incredible amount of marine life that clung to the rock. It is as if the rock were located in another ocean and not just a short distance away from the relatively barren Hin Daeng. The name derives itself from the thick purple growth of soft corals that are everywhere. The rock itself is approximately 200 meters long, less than 20 meters wide, and is shaped like a loaf of bread with steep, vertical sides and a rounded top. The walls are decorated with large sea fans of red, white and orange. Clouds of glassfish, or silver-sides school around the fans and rocky outcroppings. Carpets of anemones cover the shallower sections of the pinnacle.


    Commonly, the water is so transparent and the sea so smooth that I can clearly see the splash of someone throwing the dregs of their coffee overboard–with puffy white tropical clouds as a backdrop–from a depth of over 45m (150ft)!


    Whale sharks are one fish that we see repeatedly around these pinnacles and many years we see them on most of our trips there. Though we see whale sharks less now than we did in the 1990s, they are still around on a regular basis. Manta rays are rapidly becoming more of a common reason for diving in Hin Daeng as the tops of the pinnacles act as cleaning stations for these giants.


    Hin Daeng (Red Rock) is marked on Thai nautical charts thusly, and we do not know where the name came from although I suppose fishermen named it because when the sun is setting the rock does glow a reddish color. During the day it’s brown, but “Brown Rock” doesn’t roll off the tongue nicely in either English or Thai.


    Hin Muang (or meuang) was named when we found the dive site in about 1991 when my company started doing regular trips there. At that time, there were not many soft corals on Hin Daeng, it was mostly barren with some large sea fans deeper on the wall. Hin Muang, on the other hand, was so full of soft corals when we found the rock that it was promptly named Purple Rock because the whole thing was completely purple!


    Over the years we’ve learned that soft corals come and go. Some years they are very lush and abundant, others less so. Hin Daeng is often just as lush as Hin Muang. This may be because of the nature of these types of soft corals or it could be caused by humans and destructive fishing practices. Either way, they always seem to recover.

    Phuket International

    Chalong Harbor

    Thap Lamu Harbor

    Ranong Pier

    Similan Islands National Park

    Surin Islands National Park

    Koh Bon

    Koh Tachai

    Koh Phayam

    Hin Daeng & Hin Muang & Koh Rok

    Koh Ha

    Phi Phi Don

    Phi Phi Lae

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