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Khao Lak Liveaboards
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Similan diving, including Koh Bon, Koh Tachai and Richelieu Rock is the best Thailand scuba diving on offer. The topography of the dive sites is varied, the water is crystal clear and sometimes the Similan Islands can be full of surprises.

Diving in the Similan Islands
Join our unique Khao Lak diving day trips on a traditional Thai longtail boat and dive the fascinating Boonsung Wreck

The Similan Islands National Park is open now until end of April 2015!

Until then, no liveaboard operations and no daytrips will take place. If you have any questions concerning a visit to the Similan Islands ask our experts.

read here: further information:


The diving season is from mid October to end of April!

From May to mid October the Similan National Marine Park is closed and entering within these months is illegal and also highly dangerous because of the prevailing weather conditions!


In the past couple of years a lot of attention has been drawn to the current conditions of the Similan Islands. To a small extent the 2004 Tsunami, but more importantly the South East Asian coral bleaching of 2010 has had a dramatic effect on Thailand's dive sites in general leaving some areas in a depressing and sad state. The Similan Islands, once hailed as one of the top ten dive destinations in the world has lost some of it's shine in recent years.

Dead Seafan in the Similan IslandsFew Similan dive sites escaped the bleaching unscathed. Unregulated and unsustainable commercial fishing is also taking its toll on the Andaman Sea area as a whole and there are clear signs of a dramatic fall in shark and manta ray sightings. Nevertheless, you will be hard pressed to find better diving on offer in Thailand especially if you include the more remote and lesser known dive sites, Koh Bon, Koh Tachai and Richelieu Rock which most Similan liveaboards include on their itinerary.

Not wanting to gloss over facts, the marine ecosystem, especially here in Southeast Asia is under considerable pressure. However there were signs of improvement in the 2011/2012 diving season with a lot of new coral growth observed. Whether this is only short term or long term remains to be seen.

We logged many breathtaking dives during this season, you just have to know where the good spots are. Guests were often surprised as to the amount of reef fish at many places as well having the opportunity to dive with Manta rays at Koh Bon and Koh Tachai. Richelieu Rock remains in a class of it's own and is still worth it's world's top ten ranking. Unfortunately guide books, PADI and other websites are slow to react to changes in conditions and reports of frequent whale shark sightings at Richelieu Rock should be taken with a large pinch of salt. Whale sharks, sadly, no longer orbit Richelieu Rock like satellites. The Andaman Sea and especially the Similan Islands has seen a dramatic fall in whale shark sightings over the last few years, along with sightings of white and black tip reef sharks, nurse sharks and leopard sharks.

As long as you are well informed and have a realistic idea of what to expect, not relying on false promises made by many operators and you dive with experienced dive guides, you can certainly have exciting and thrilling dives in the Similan Islands.

Since 2010, there are many bad reviews and comments about diving in the Similan Islands on various scuba forums. Most of these reports are authentic, underwater deserts do exist, but there are still some areas that are largely intact. These tend to be for more advanced divers and led by the experienced dive guides. Reports on great dives since 2010 can also be found on the Internet and in equal in numbers. So what can you expect from diving in the Similan Islands?

Similan Diving at Koh Bon

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Turtle at Breakfast Bend in the Similan IslandsIf you are a novice diver, diving Similan Islands is often a wonderful experience. Many of the sites offer easy diving conditions, crystal clear water and the good chance to see firm favourites such as turtles, anemone fish, moray eels, stingrays, pufferfish, lion fish, batfish and occasionally larger pelagic species such as barracuda and trevally. If you include diving at Koh Bon which is often included in a weekly Similans schedule then there is a good chance to see Giant manta rays at certain times of the season. The diversity of dive site types is a strong point of the Similan Islands. Gentle sloping coral reefs form on the east side of the islands, while rocky reefs dominate the west sides. There are also a number of submerged pinnacles that form dramatic underwater seascapes and create adventurous dives through caves and swim throughs which adds appeal for more experienced divers.

If you are a more experienced diver or have already logged a lot of dives at some of the world's great locations (e.g. the Red Sea) you may find similan diving not quite what you expected. Apart from notable Similan dive sites such as Elephant Head Rock, Christmas Point and West of Eden you will find the dive sites to the north of the Similan Islands more fitting to your experience level and expectations. Koh Bon, Koh Tachai and Richelieu Rock are more advanced dive sites and due to positioning and stronger currents offer a better chance to see larger marine life. Manta ray sightings, although on the decline are frequent at Koh Bon and Koh Tachai, especially between the months of January and March. Whale sharks do occasionally pass by Koh Tachai and Richelieu Rock. Abundant soft corals and sea fans coupled with large quantities of fish life and larger pelagic species set Koh Tachai and Richelieu Rock in a much higher class of diving.

Do not expect to be alone at the Similan Islands. With all guide books, internet sites and local operators selling the Similan Islands as one of Thailand's top destinations you will find the islands and dive sites crowded. Unless your Similan Island trip includes divers, snorkelers or beach lovers in one group, avoid trips to the Similan Islands offering all activities from only the one large vessel, otherwise you will be snorkelling at dive spots or diving snorkelling spots whilst feeling the tremendous time pressure to complete your planned day! Thailand Dive and Sail recommend trips that separate their diving and snorkelling activities, with fast transfers to the Islands and also offering weekly schedules that include the better diving at Koh Bon, Koh Tachai and Richelieu Rock. Boats offering only a Similan Island and Koh Bon weekly schedule are not offering you the best of the Andaman Sea area.

Our photo blog, updated daily, gives a perfect overview of what you can expect to see diving the Similan Islands, Koh Bon, Koh Tachai and Richelieu Rock. You can browse the photos by serval categories including by dive sites, by locations and by fish common names and species names.

Interested in diving with a highly experienced and knowledgable team in the Similan Islands?

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If you plan your similan diving activities to be conducted as day trips, Thailand Dive and Sail recommend the following trips for the scuba diver who wants to get the most out of their limited time in Khao Lak.

A day trip to Richelieu Rock must top the list. This is by far Thailand's premiere dive site. We offer a fantastic speedboat day trip to Richelieu Rock. Diving from our speedboat limits the number of divers jumping in at the same time whilst every attempt is made to jump in at different times from the busy live aboard schedule operated at Richelieu. Fast transfers to and from Richelieu Rock means a later pick-up time in the morning and an earlier arrival back at you hotel.

A day trip to either Koh Bon or Koh Tachai to hopefully dive with larger marine species such as Manta Rays. Thailand Dive and Sail offer a speedboat trip which visits both of these top destinations in one dive day.

A local dive trip to the amazing Boonsung Wreck, just off Khao Lak's coastline. Thailand Dive and Sail offer a true Thai diving experience to the wreck. Our traditional longtail boat departs directly from one of the areas most beautiful white sandy beaches and takes a mere 30 minutes to reach the dive site. Although the visibility is often not as clear as the islands further out in the Andaman Sea, the quantity and quality of the fish life there is surpassed only by Richelieu Rock. Experience has shown us that the wreck is regularly quoted as one of the best dives on offer.

If you have the time, by far the best way to maximise your dive time in the area is on a Similan Island Liveaboard. You get the chance to see the Similan Islands at quieter times of the day and spend some time on the beaches there before heading north to the better dive sites. Most live aboard trips are four day/four nights although Thailand Dive and Sail also offer flexible two, three, four and five day trips. Read more about Similan liveaboards.

Similan Island Liveaboard

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One of the best days out I can remember. Super diving and looked after brilliantly.

"I had a truly super day out with these guys today. All the arrangements were excellent and i was well looked after by some really nice people. Did a days diving from a longtail boat. Lovely way to do it at a relaxed pace to a fantastic dive site. Having travelled and dived extensively I can honestly say this was a world class experience. I would not hesitate to recommend this to others. Top notch."

★★★★★ by Spikerstravels 30.11.2011


Follow these quick links for our new and updated liveaboard information

Monthly liveaboard schedules

Read our liveaboard dive logs on our blog


Thailand Dive and Sail LogoThe philosophy behind Thailand Dive and Sail is to provide divers with the right trip tailored to their needs. Built up of a small team of experts who have dived in the Similans for more than a combined 25 years, our knowledge about this amazing Thailand diving destination is almost unrivalled. Read more about Thailand Dive and Sail


Ric Parker
Ric Parker

“My story of getting into scuba diving, and then shark conservation, is a story that starts with me ‘not’ getting into scuba diving, mainly because of a fear of sharks.

Back in 2001 I had been in Thailand for 3 weeks and was snorkelled out. I was really nervous about the diving... Read more...

Ric Parker
Clive White

Clive has always had a close affinity with the sea; he grew up in the south of England from the age of 12 and the sea was never far away.

The ocean beckoned from a young age and he spent a lot of his childhood either sailing or windsurfing... Read more...


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Thailand Dive and Sail • 4/88 Soi Bang La On Moo 7 • Khao Lak • A. Takua Pa 82190 Phang-Nga • Thailand

   Tourist Authority ThailandTAT Number: L.34/00715

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