The Koh Surin is located in the Andaman Sea and covers an area of approximately 135 square km. From completely submerged pinnacles to fringing reefs, any variation can be found on this dive site. The Surin islands offer the most abundant coral spectrum in all of Thailand and divers can encounter eagle rays, turtles, and larger pelagics are possible here.

• Dive Type: Boat Dive
• Diver Level: Advanced Open Water Diver
• Max Depth: 30m

Richelieu Rock is one of the best places in the world to dive with whale sharks and is easily the best site in Thailand diving for this amazing activity. Here divers will encounter the largest fish in the ocean which are rare almost everywhere in the world. With nothing else for miles around, the whale sharks are attracted to the rock to feed on the rich plank tonic blooms that occur here.

• Dive Type: Boat Dive
• Diver Level: Novice Diver - 20 + Dives
• Max Depth: 40m

Koh Tachai is located in Tachai Island and lies about halfway between the Surin and Similan Islands and is rated as one of the best sites for Thailand scuba liveaboards as it's normally visited on the way to Richelieu Rock from the Similans. There are several dive sites around the island but the most famous is Koh Tachai Plateau which lies southeast of the island, about one kilometre offshore. The plateau is a submerged crowned reef of hard sheet corals, and scattered boulders. These boulders provide great swim-throughs and cut-through opportunities.

• Dive Type: Boat Dive
• Diver Level: Advanced Open Water Diver
• Max Depth: 35m

This dive site is one of the best places in Thailand to see manta rays, especially from April to May.
Koh Bon Island lies an hour or so north of the Similan Islands. It has a 33 metre wall on its south side, facing a small cove, with a stepped edge pointing west and down to over 40m.

Here divers will have the opportunity to see leopard sharks, white tip sharks; soft corals the colours of turquoise, yellow and green dominate. If you listen carefully you'll hear the warning clicks of hundreds of nervous damselfish, and the coral crunching of hungry titan triggerfish.

• Dive Type: Boat Dive
• Diver Level: Novice Diver - 20 + Dives
• Max Depth: 40m

This is one of the most colourful, scenic and often exciting dive sites in the Similan Islands. The dive begins at Christmas Point by heading down a mooring to a sand-rubble bottom at a depth of about 20 metres, then heading deeper to the southwest where divers will find several giant arches and some of the best swim through in the Similans. The rock walls are highlighted by radiant soft corals and the sea fans can be very large here. Here divers will have the opportunity to see ribbon eels and fire gobies, and check the sand plains beyond the arches for white tip or leopard sharks.

• Dive Type: Drift Dive
• Diver Level: Novice Diver - 20 + Dives
• Max Depth: 40m

The Donald Duck Bay is named after a rock on the north side of the bay that resembles the cartoon character not the most prominent large boulder that balances precariously at a seemingly impossible angle. This dive site on the North West corner is the most popular mooring spot for day trippers and Similan Islands liveaboards alike. Here divers will have the opportunity to see molluscs, gastropods, crustaceans, cephalopods, huge bull crabs, red octopus, cuttlefish, all hunting for scraps and morsels. The most interesting section of the dive site is the boulders running out of the bay on the northern edge. These form several swim-through, and house emporer shrimps, red round crabs, decorator crabs, triton shells and cone shells.

• Dive Type: Boat Dive
• Diver Level: Advanced Open Water Diver
• Max Depth: 20m

This dive site has impressive series of submerged boulders and swim through in typical Similan fashion. Surrounded by coral and marine life this is one of the better places to spot turtles. Here divers will have the opportunity to see big pelagics and eagle rays. To the northeast of the Turtle Rock there is an impressive 3 metre wide canyon to swim through.

• Dive Type: Boat Dive
• Diver Level: Advanced Open Water Diver
• Max Depth: 30m

The Fantasy Reef is a great spot to enjoy the grandeur of underwater boulder formations that cover a huge area. This dive site is located on the west coast, the friendliest fish in the Similan Islands hang out here, including clown triggerfish, normally a difficult fish to approach, and cow tail rays in the sand.

• Dive Type: Boat Dive
• Diver Level: Advanced Open Water Diver
• Max Depth: 30m

Here divers will have a new option to choose for the PADI Advanced Open Water Course - wreck diving in Thailand! The boat breached on the hard coral, and gradually sank backwards so that the bow lies in 16metres of water, and the stern 30metres.

Atlantis X was a 27metre twin-engine mono hull cruiser, offering a wide range meals and beverages. Unfortunately, all the beers have now been removed from the wreckage. Although the wreck has had little time for coral growth, you'll still have the pleasure of seeing batfish, lionfish, hundreds of juvenile fishes, and a black-blotched stingray.

• Dive Type: Boat Dive
• Diver Level: Advanced Open Water Diver
• Max Depth: 30m

Beacon Reef is located just to the south of Beacon Beach and features a steep drop-off with a striking diversity of hard corals from 35metres almost to the surface. This site has the greatest variety of healthy hard corals in the Similan Islands, exceeding 300 species. There are countless nudibranchs, scorpion fish and devil firefish, one of the most beautiful fish in the sea.

• Dive Type: Boat Dive
• Diver Level: Advanced Open Water Diver
• Max Depth: 35m

The site is named after an unusually shaped rock that juts out of the water just southwest of Koh Similan. The huge boulders that form Elephant Head Rock create daring swim-through, arches, caverns, gullies and tunnels. Here divers will have the opportunity to see fronds, colonies of spiders crabs, large black egg cowries, cuttlefish and mantis shrimps as you sink further down to entrance floor.

• Dive Type: Boat Dive
• Diver Level: Novice Diver - 20 + Dives
• Max Depth: 45m

This is another deep dive following a ridge on the north side of the island that features finger table corals, feather stars and large knotted fans in its deeper sections.

Green turtles, white tip reef sharks and leopard sharks can be found on the sand. The marine life that divers will encounter here are tuna, rainbow runners, yellowtail barracuda, blue fin trevally and yellow spot and Java rabbit fish, with lots of blue-spotted sting rays.

• Dive Type: Boat Dive
• Diver Level: Experienced Diver - 50 + Dives
• Max Depth: 50m

The East of Eden is located on the southeast coast of the island; this dive site has the most incredible bommie in the Similan Islands. Just to the south of the main reef and from a depth of 21 metres up to 12 metres, the concentration of marine life is beyond compare in the Similans. The main body is covered in an overwhelming array of blue and purple soft corals, lobophyton soft corals, and red bulb tentacle anemones hosting skunk anemone fish and western clownfish. Small groups of red tail butterfly fish, checkered snapper and yellow boxfish are always present.

• Dive Type: Boat Dive
• Diver Level: Advanced Open Water Diver
• Max Depth: 35m

The Bird Rock is also known as Chinese Wall. This site is one of the better places to spot giant moray eels hiding in the rock crevaces. Coral gardens can be found in 12 metres of water to the west of the wall and further on are a series of boulders, overhangs and swim through.

• Dive Type: Boat Dive
• Diver Level: Advanced Open Water Diver
• Max Depth: 30m

The Shark Fin Reef will offer diver two different sceneries. The northeast which features a sloping reef and the southeast which is a more dramatic drop-off. A series of parallel rocks resembling fallen logs are the setting for this Similan diving site.

To the southeast is a large swim-through that provides an opening to the other side of this dive site. The marine life here is diverse with clown triggerfish, half-moon triggerfish and schools of batfish, palette surgeonfish, blue-faced angelfish and banner fish. It's also a good place to spot passing sharks and larger rays.

• Dive Type: Boat Dive
• Diver Level: Novice Diver - 20 + Dives
• Max Depth: 40m

Boulder city is a submerged site about one kilometre off the east coast of island number 3 and about 400 m south east of Shark Fin Reef. Due to its exposed location, divers will have the opportunity to see almost anything on this Similan dive including whale sharks and manta rays.

There is very little coral growth here except for green branching cup corals and orange sea fans, but the algae growth here is substantial, meaning a prolific amount of nudibranchs, including the twin magnificent sea slug and Spanish dancers. Leopard sharks are frequently seen as well as white-tip and black-tip reef sharks.

• Dive Type: Boat Dive
• Diver Level: Advanced Open Water Diver
• Max Depth: 35m

The Coral Gardens offer divers a gentle sloping of hard coral plateau in a sheltered bay ideal for the first dive at the Similans or for inexperienced divers. Abundant hard corals include staghorn, plate and brain varieties teeming with smaller reef fish such as anthias, fusiliers, damsels and gobys.

• Dive Type: Boat Dive
• Diver Level: Advanced Open Water Diver
• Max Depth: 25m

This is one of the area's best scuba diving day trips sites for spotting leopard sharks and octopus. This place has it all. Leopard sharks are the norm, swimming along the wall or resting on the seabed with the stingrays down at around 20-25m. Whale sharks and manta rays are occasional visitors at this daytrips site too. On our swim through the rocks and coral we'll see a plethora of tropical marine life typical of Phi Phi Island. Green turtles and octopus are regularly sighted, as are seahorses.

• Dive Type: Boat Dive
• Diver Level: Advanced Open Water Diver
• Max Depth: 25m

Koh Ha is a group of five magical uninhabited islands, unspoiled and usually offering crystal clear waters. One of the highlights is diving the Twin Cathedrals, a large cave system that has formed into two large domes with a passage between them. This island group is a haven for marine life and divers alike! overwhelming beauty with caverns, caves, chimneys, swim throughs, soft coral covered walls, coral heads and sea bed. The marine diversity here will suit all divers with interesting macro such as sea horse and rare nudibrancs and good fish action plus squid, cuttlefish, lobsters, morays and more.

• Dive Type: Boat Dive
• Diver Level: Advanced Open Water Diver
• Max Depth: 20m

The Thai name for this spectacular rock is “Hin Muan Deaw” and is the best way to describe how beautiful this rock really is, as it directly translates to “Whole roll (of film) rock”, as one can use an entire roll film solely on this rock. Shallow coral gardens comprise huge pore and staghorn corals with small pinnacles. A big outcrop located on the southeast makes this dive site unique and attracts many photographers. Colorful soft corals, gigantic sea fans, and many species of hard corals surround this fantastic rock.

• Dive Type: Boat Dive
• Diver Level: Open Water Diver
• Max Depth: 18

This dive site rivals its neighbor, in fact there really is no separating either site, apart from the landscape differing slightly, both sites teem with life and both make for amazing diving.

On one side there is an almost vertical wall with Gorgonian Sea Fans and soft red corals, as you swim mid water with the bottom sloping off into the deep, keep your eyes peeled for large pelagic fish that cruise these waters very frequently.

Another special feature here is the huge boulders that form swim throughs. There is also a valley that splits from part of the main island; it’s worth exploring this area too. The shallow side is around 15 meters, and then on the other side, it drops down quite deep.

Here you can find Red Tooth Trigger Fish and also Clown Trigger Fish favoring this area too. There is a mooring line which divers use to descend and ascend and usually there to greet them are the resident Bat Fish. These fascinating fish are very curios and seem to come very close to see especially if the diver rubs their fingers together.

Venturing further around the reef, it is quite visible how quickly it drops of into depth of blue; regular depth surveillance is recommended. The large pelagic fish are a common sighting in this particular part and this great spot to observe them, as they swoop in and gobble up any plankton that is in the area.

The whole rock is covered in absolutely stunning red soft corals, hence its name Hin Deang (Red Rock). The area attracts very small glass fish and bait fish, this attracts the more active Jacks and Trevally’s that come here to hunt and to terrorize the smaller fish.

If it’s possible, find a nice quite area, buoyancy permitting, and observe the show. It is fantastic. Better than any wildlife TV program. There is a huge school of Pickhandle Barracuda, also lone-wolf Great Barracuda’s, as they go lurking and quietly follow the diver, curious as to what the bubble blower is doing.

There is a huge variety of Moray Eels down there, including Honeycomb and Zebra morays, which are rarely seen elsewhere. Snake Eels have also been seen scuttling around the bottom. In fact the variety of macro life at Hin Daeng is unique to the area. Several species can only be found here.

The Harlequin box shrimp are not always easy to see, it takes a shrewd diver to realize that any four legged starfish may have been recent victims to these little critters.

• Dive Type: Boat Dive
• Diver Level: Open Water Diver
• Max Depth: 60m

The first pinnacle lies approximately 8 meters from the surface and drops down to 70 meters. Many divers have seen their first Manta Ray and or Whale Shark here, as these magnificent creatures are attracted by the deep drop-offs and plankton rich waters.

There is an abundance of soft corals, reds and particularly purples and this is where Hin Muang gets it name: Purple Rock in English, a beautiful site to see. The main feature, being the two large pinnacles you will find yourself diving in a figure of 8 as you admire the wonders around.

Again, this is a large dive site, over 200 meters in length and it’s very deep too, easy to go deeper than you planned for, so monitoring air and depth frequently is recommended.

Hin Muang is a completely submerged ridge, it is connected to Hin Deang, but it would take a foolhardy diver who would attempt this 500 meter swim, at over 70 meters depth, without a fully operational nuclear submarine.

Again, here as on its sister site, there is loads of predatory action here, huge Rainbow Runners hunting beside Giant Trevally. The attacks on the small bait fish can be relentless. Other fish life in the area: Schools of Squid, Large Red Octopus scampering across the reefs, Black Fin Barracuda and Yellow Tail barracuda too.

The amount of macro life here will have the photographer drooling, Pipefish, Blennies, Gobies all hiding among the small cracks and crevices of the rock. Searching around the huge Gorgonian Sea fans will also yield a fantastic wealth of macro life.

The only downside to this site is there is never enough time to see it all, so at least two dives are needed here. As the minimum depth is 8 meters, it is quite a deep site to tackle and the currents can be strong creating excellent drift diving.

• Dive Type: Boat Dive
• Diver Level: Open Water Diver
• Max Depth: 70m