THE SIMILAN ISLANDS

The Similan Islands (or Koh Similan) is by far the most beautiful group of dive sites in Thailand and one of the best areas for diving in the entire world. Many people comment that the most fantastic thing about the Similans is the two radically different types of environments all rolled together into one destination. Nowhere else in the world will a diver find such diverse topography in such a small area.

The Similan Islands are composed of nine granite islands covered in tropical jungle, washed by a clear blue tropical ocean and blessed with some of the world's finest beaches. The islands lie around 6 hours cruise offshore from the town of Khao Lak, the nearest point geographically to the Similans on the Thai mainland. Khao Lak is our departure point and just under an hour's drive from Phuket International Airport.

Similan comes from Malay fisherman who named it "The Nine Islands" (Semilan is "nine" in Malay) and now the islands are identified by a nameñin Thaiñand a number; for example, Ko Huyong (Island #1), located at the southern end of the chain or Ko Miang (Island #4) located in the middle. The islands have achieved national park status and thus are fully protected under Thai law. Recently, the islands have come to the special attention of the Thai Royal Family which further protects them from possible abuse.  The 2004 tsunami caused varying damage to some of the Similan Islands both above and below the water, but three years on there is little evidence that this tragic event even occurred. 

There are two distinct types of diving in the Similans.  The first  are hard coral gardens which slope dramatically from the surface down to approximately 30-40 meters, where sand takes over as the water depth increases. Drift diving along these huge slopes while watching the reef inhabitants go about their business makes for fascinating and restful diving. In several sites, large coral bommies rise from the bottom and are covered with soft corals, sea fans, and an enormous amount of critters and unusual fish. Here the diving is easy and navigation simple, allowing each buddy pair to explore at his or her own pace.

The second type of diving is the exhilaration of the huge granite boulder sites - some larger than the largest of houses. These smooth, rounded boulders make dramatic formations, holes, and overhangs underwater where divers can enjoy swimming with the current through the openings. The drama of just 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 fans grow to a size sometimes three meters across, and are often so tightly bunched together that it makes it impossible to swim through the passages. Most of the dive sites on the West Coast are guide dives, since navigation can be tricky.

If you enjoy watching and photographing small fish, the Similans are hard to beat for the sheer numbers and varieties of tropicals especially lionfish and anemone fish. Manta rays and leopard sharks are frequent visitors to the Similan Islands and you may see an occasional whale shark if you are very lucky. We will also see white tip and black tip sharks once in awhile, and possibly schools of pseudo orcas or false killer whales. The point is, like all diving areas, enjoy the Similans for what they are famous for; wild, unspoiled beaches, magnificent coral growth, prolific fish life, crystalline blue water and sensational underwater rock formations.

High season in the Similans is from October until May, but diving is possible all year-round, although we only offer tours from October to May due to the potential of monsoons from June until September. Visibility is almost always good in the Similans, averaging approximately 18-25 meters and at times exceeding 40 meters (120 feet)! There are well over 30 charted dive sites in the Similan chain, and the following short descriptions of a few of our favorites should give you an idea of what to expect.

East of Eden, Island #7, Koh Payu:

A typical East Coast dive, this particular site has one of the most incredible underwater bommies in the Similans. Beginning at about 21 meters and continuing up to about 12 meters, the concentration of marine life is unequaled in the Similans.  Don't just take our word for it - this bommie has been featured in a host of underwater television documentaries, including National Geographic.

Breakfast Bend, Island #9, Koh Bangu:

The light is beautiful early in the morning hence its name, and the coral is in great shape. Down deeper in the sand, there has been a large increase of garden eels over the past few years. In the shallows, leopard sharks are often seen resting in the sand.

Elephant Head, Island #8, Koh Similan:

Named after an unusually shaped rock that juts out of the water just southwest of Ko Similan. The three rocks that form Elephant Head also create a natural amphitheater that feels like you are diving in a huge aquarium. Yellow goat fish and snappers always hang around at the deepest level of the bowl, as well as several species of lion fish, coral trout, and the occasional hawks bill or ridleys turtle. The swim-throughs at deeper depths are dazzling.

Koh Bon

Koh Bon is Thai for "Hope Island", and many divers hope they'll come face to face with a manta ray here  as the island is famous for being a manta meeting point.  A dramatic wall that drops vertically from the surface, Koh Bon's dive site levels out around 45 feet with a vast bed of staghorn coral and numerous rocky nooks to explore.  If divers stay near to the wall and keep glancing out into the blue, they may well be rewarded by the majestic sight of one or more mantas suddenly gliding beside them.

Richelieu Rock

Widely regarded as the best dive site in all of Thailand, Richelieu Rock is a big horseshoe shaped pinnacle that's alone in the middle of the Andaman Sea. The top is just visible above water but below its distinct bulk provides shelter to hundreds of marine life species. Sometimes it's hard to see the rock for all the glassfish around the descent line, and the walls are alive with ghostpipefish, stonefish, morays and scores of reef fish. Manta Rays are occasionally seen orbiting the rock and Richelieu is also known as a whale shark hotspot, with 4 or 5 sightings each season of the biggest fish in the world.

A Final Word

The Similan Islands are unique for another reason as well. Mooring projects and other environmentally protective measures have been introduced over the past few years and happily, the diving has actually improved. While we hear that other areas of the world deteriorate due to thoughtless management, the diving in the Similans just gets better and better. One thing is for sure, the Similan Islands will give all that you ask of it-and more.

I would like to thank the people at Pocket Divesite Team in Thailand for the wonderful illustrations used on this page. For more information on their quality books and how to order them for your Thailand trip, visit our links page here.