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

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

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

At 85m in length, King Cruiser is a large wreck as she had previously been a car ferry, and now she is a wonderful artificial reef offering best scuba diving Thailand wreck diving, and with each passing year more and more different varieties of marine life make the King Cruiser wreck their home. The King Cruiser wreck lies on the seabed at 31m, yet the top is just 14m deep, so the King Cruiser wreck caters for all levels of diver.
Lionfish, scorpionfish and porcupinefish are other notable residents. With it's multiple decks, great open passages and depths between 15 and 30 meters (50 to 100 feet) the King Cruiser used to be a fairly easy dive. In the last 2 years however the condition of the wreck has deteriorated and it has collapsed in places. There is now very little shelter from the currents in shallow parts and we recommend this site only for Advanced certified divers.

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

West of Eden basically comprises giant granite boulders that create nice canyons, with walls covered with colorful soft corals and giant sea fans. Some areas are characterized by rubble and sand slopes. The shallows are home to many reef fishes, and have stacked granite boulders covered with hard corals, soft corals, gorgonians and feather stars. This area is a nice place to look for macro subjects like nudibranchs and frogfish. Keep an eye out for cleaner pipefish and many banded pipefish in small crevices, as well as long-nose hawkfish perched in black coral bushes. The rubble and sand slope are good place to search for ribbon eels, dragonets and red fire gobies. Back at the reef, moray eels are quite common, as well as turtles and schools of angelfish. Occasionally, whitetip reef sharks cruise by.

• 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

The Boonsung Wreck is often described as ‘Fish Soup’. The density of marine life here is often better than most dive sites in the Similan Islands. An old tin mining vessel, surrounded by sand for miles in every direction, provides the perfect protection for thousands of juvenile fish. The schools of fish are huge and the variety of Macro life is one of the best in Thailand. This is a real divers dive site and part of a fascinating history of Tin mining in the Phuket and Khao Lak area.

The Boonsung Wreck is located about 5km West of Bangsak beach, to the North of Khao Lak. Visibility is typically not as good as the Similan islands. However, the huge variety of marine life makes it well worth seeing. It is a regular final stop on many Similan Liveaboards, although it is technically not part of the Similan islands. The Boonsung wreck also makes for an excellent and speedy day trip by longtail. The Boonsung Wreck is the best value dive around Khao Lak.

• Dive Type: Boat Dive
• Diver Level: Open Water Diver
• Max Depth: 19m

The wall, part of the Similan National Park, is decorated with various colorful soft corals and hard corals. From the ridge to the northeastern side are reefs that stretch along island. The reef slopes from a depth of 10m down to a sandy bottom at 25 - 30m. The majority of corals here are hard corals, including staghorn coral and brain coral that are interspersed with a few big coral heads. To the northwest of the island, there is a submerged pinnacle. The pinnacle is at a depth of 18 - 45m and is covered by an abundance of yellow soft corals and large sea fans. This site is a cleaning station for manta rays, so there is a high chance of finding at least one during a dive, particularly at the western ridge and northeastern outer reef. Koh Bon also has many kinds of sharks, such as leopard sharks and whitetip and blacktip reef sharks. Sometimes grey reef sharks swim by, and nurse sharks can be seen lying under coral heads. Schools of yellowtail barracuda, fusiliers, trevally, sweetlips and black and white snappers are all common in the area, as well as octopuses, sea snakes, and nudibranchs.

• Dive Type: Boat Dive
• Diver Level: Advanced Open Water Diver
• Max Depth: 45m