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

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

Koh Racha Yai Island (literally "Big King Island") lies 10 km south of Phuket and provides a wealth of dive sites is a beautiful tropical island with plenty of good hard coral reefs, colourful shallow water coral gardens, and a great opportunity for some enjoyable drift diving. There are several excellent dive sites suitable for the beginner and for snorkeling, with depths from 2 - 20m, making these islands a favourite destination for everyone.

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

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

5 km south of Racha Yai Island, and 15 km south of Phuket lies Koh Racha Noi ("Little King Island"). You may see this island also referred to as Raja Noi Island or Raya Noi Island.
This is the furthest scuba dive sites Phuket destination one can comfortably travel in a diving day trip from Phuket. Beyond this is the open Andaman Sea and the scuba diving Thailand feeling at Racha Noi Island is definitely more oceanic. The extra depth and distance from land means the visibility is generally the best out of the scuba dive sites Phuket day trip destinations collection.

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

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

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