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 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

Shark Point (Hin Musang), a small rock outcropping about 1½ hours East of Phuket, is a famous marine sanctuary due to its tremendous variety of marine life. The dive Shark Point site consists of 3 pinnacles. "Shark Point 1" is the northern-most, the one that breaks the surface. Next comes "Shark Point 2", rising to a depth of 7 meters, and further south lies "Shark Point 3", rising to 10 meters. All three scuba diving Thailand dive Shark Point pinnacles can be explored within the same dive.
Particular attractions you should look out for are the colourful soft corals, gorgonians and sea fans decorating the limestone pinnacle, the great range of tropical fish and the famous leopard sharks, often to be found resting on the sandy bottom. This site and the neighbouring Anemone Reef are also good for macro life.

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

This submerged reef, located not far from Shark Point is similar in character and you will be amazed at the extensive fields of sea anemones covering the shallower areas of the reef. Harmless leopard sharks are also to be found together with some massive schools of smaller fish and some larger pelagics such as tuna, jacks and barracudas.

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

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

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

Tachai Reef stretches through the eastern side of the island, going from the northeast to the southwest. Hard corals cover the entire area, most of which are staghorn corals, pore corals, brain corals, and fire corals. Divers regularly see leopard sharks lying at the outer sandy area and sometimes in shallow areas. Large stingrays are found on occasion too. General reef fish include pufferfish, lionfish, parrotfish, and moray eels. At night, several species of crabs and shrimp come out to hunt. It is possible to see twin-spotted lionfish, a rare species of lionfish that tends to be shy and hide in crevices. Cuttlefish, nudibranchs and flatworm are also common.

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

Tachai Pinnacle or Twin Peaks are a pair of submerged pinnacles located 500 m south of Koh Tachai. The southern pinnacle is bigger and is a dome shape surrounded by large boulders. To the west you will find large boulders, some of which have formed swim throughs. In the east, you will find stacks of small rock, most of which are cover by hard corals and sea whips. Colorful soft corals and sea fans dominate the northern area. The top of the pinnacle is a wide flat plain with bush and mountain coral. The smaller pinnacle comprises of a wide range of rock clusters and is home to large sea fans and corals, which are similar to the ones found in the southern pinnacle.
Manta rays visit this area for feeding and circling around the pinnacles. Some divers have encountered whale sharks as well. On the outer sand bed, divers can usually see leopard sharks, sometime three to four of them in the same dive. In addition, it is possible to find Jenkin’s rays, as well as whitetip sharks and blacktip reef sharks here as well. Swarm of chevron barracuda, bluefin trevally, batfish, snappers, and fusiliers are common here.

• 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

Koh Bida Nok is the sister dive site of Koh Bida Nai located 2 km south of Koh Phi Phi Ley. It is regarded as one of the best diving spots of Koh Phi Phi. The Marine life is teeming and you can spot various Sharks like Blacktip, Leopard Sharks, Nurse Sharks as well as turltes and Moray Eels. It is not rare to also see a banded sea snake. From December to February, It is sometimes possible to spot a Manta ray or even a whale shark if you are very lucky! The wall is covered by superb Sea Fans dancing in the current. The maximum depth is 33 meters deep and the current can be strong, so this site is more suitable for advanced divers. The spot is also called “Outer Father”. As it is an excellent dive site it often visited by Liveaboards from Phuket or Khao Lak

• Dive Type: Boat Dive
• Diver Level: Open Water Diver
• Max Depth: 33m

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

Like its sister island, Koh Bida Nai has an amazing topography of underwater crevices, huge boulders, and fields of staghorn reef. Stretched across the south and west coasts of the island is a gradual reef slope that starts at a depth of 5-10 m and is made up of hard corals like pore corals, table corals and staghorn corals. There are also some big boulders and a swim-through on the southern side. The eastern side of the island is a big sand slope with fields of staghorn corals. Divers can find leopard sharks snoozing in the island, or swim out to the large pinnacle beyond the reef for the big school of trevally, barracuda, and other fish. The top part of the pinnacle is around 14-18 m from the surface, and goes to depths of at least 30 m.

Schools of barracuda and trevally are often sighted near the east pinnacle, as are snappers, mackerel and other pelagic species. Divers may also see sea snakes, cuttlefish and Kuhl’s stingrays. Macro species such as ghost pipefish, nudibranchs, and porcelain crabs are also frequently sighted.

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

King Cruiser was a car and passenger ferry servicing the Phuket to Phi Phi Island route that sank on 4 May 1997 after hitting a submerged rock known as Anemone Reef on its way to Phi Phi Island. Fortunately, no lives were lost during the incident. Having fortunately settled in an upright position at the sandy bottom, the wreck stays relatively close to Anemone Reef and Shark Point and is 25-27 km. east of Chalong Bay with a north-south orientation. The depth is around 32m at the sand bottom and about 14-15m on top.

• Dive Type: Boat Dive
• Diver Level: Open Water Diver
• Max Depth: 15m