The Similan Islands National Park. The Similan Islands (Thai: หมู่เกาะสิมิลัน, RTGS: Mu Ko Similan, Thai pronunciation: [mùː kɔ̀ʔ si.mi.lan]) is an archipelago in the Andaman Sea off the coast of, and part of, Phang Nga Province in southern Thailand. It was established as Mu Ko Similan National Park in 1982 by the Forestry Department.
From north to south:
Koh Huyong
Koh Payang
Koh Payan
The waters surrounding Islands 1, 2 and 3 are protected areas reserved for sea turtle nesting and are off-limits to tourists.
4–5. Koh Meang & Koh Ha
Two connected islands where the national park has established its headquarters.
Koh Payoo
Koh Hua Kalok (also known as Koh Hin Pousar)
Koh Similan (the largest island)
Koh Ba-Ngu (home to the Christmas Point dive site)
10–11. Koh Bon (also known as Koh Talu) and Koh Tachai were incorporated into the national park somewhat later. Today, they are considered among the best dive sites in the Similan Islands.
The name “Similan” actually comes from the Yawi (the local native dialect) word for “nine” to name the cluster of 9 nearby islands in the South.
All the islands are located within Mu Ko Similan National Park, which covers more than 140 km². This beautiful and vast marine national park is well known to divers from around the world. Located approximately 70 km offshore from Phang Nga Province, it is home to gently shaped granite islands that are as impressive above the water as they are beneath the turquoise waters of the Andaman Sea. Covered in tropical rainforest, the islands are fringed with dazzling white beaches and surrounded by coral reefs.
Coral bleaching and tsunamis have damaged some of the hard corals, but soft corals are still abundant, and the marine life remains diverse and plentiful. The Similan Islands therefore remain a beautiful and popular destination for divers of all levels.
The Similan Islands are particularly renowned for their rich coral reefs, which support an exceptional variety of marine life. Divers and snorkellers can encounter many marine species, including manta rays, sea turtles and sea snakes, as well as various pelagic species and, with a little luck, a whale shark.
Beyond their underwater treasures, the Similan Islands are also home to numerous terrestrial species and birds. They are internationally recognised for the beauty and preservation of their natural environments, both above and below the water.
Unfortunately, the islands have suffered from excessive tourism. Up to 7,000 visitors per day were recorded during the 2017–2018 season. In 2018, park authorities therefore decided to limit the number of visitors to 3,325 people per day.
Visitors must now obtain a permit in advance. Your tour operator can arrange this for you using the information provided on your passport.
Located northwest of Koh Hua Kalok (Island No. 7), next to the famous Deep Six dive site.
Start on the west side above a coral nursery at 10–12 m, with schools of angelfish and snapper among hard and delicate corals.
Zigzag between granite rocks and channels at 25–28 m, surrounded by huge gorgonian sea fans. Look for mantis shrimp, moray eels, yellow-spotted pipefish and Durban dancing shrimp.
As you ascend, watch for tornado-like barracuda formations and turtles in the blue. Sunlight on the western side makes West of Eden an excellent midday or evening dive.
Maximum depth: 28 m
Difficulty level: Beginner-friendly, but divers must be certified. Open Water courses are not permitted in Similan National Park.
From the boat, this pinnacle resembles the head of a giant elephant swimming towards you — complete with imagined nostrils!
Located between Koh Hua Kalok and Koh Similan (Islands No. 7 and 8), it features a maze of granite boulders, channels, cracks, and swim-throughs from 12 to 30 m.
Start on the south side with a negative entry if conditions allow, as surface currents can carry you past the site. Regroup in a sheltered area before exploring the rocks, channels, cracks and valleys.
Look for lionfish near giant sea fans, moray eels in rocky holes, blue-spotted stingrays on sandy patches, shy seamoths and reef sharks in the blue.
Maximum depth: 30 m
Difficulty level: Intermediate to advanced — strong currents and changing conditions. A negative entry may be required.
Koh Bon is one of Thailand’s renowned manta ray sites. This limestone island offers spectacular scenery, drift diving and the chance to see mantas gliding through the blue.
Currents range from mild to strong, so your guide will choose the best entry and exit points.
Koh Bon has two main dive sites: the West Ridge and Koh Bon Pinnacle.
The West Ridge is a well-known manta ray cleaning station, where mantas often glide slowly in the current.
Further north, Koh Bon Pinnacle reaches around 18 m and makes a great first dive for certified deep divers. Zebra sharks are often seen around the pinnacle, and when conditions allow, you can cross through the blue to the West Ridge.
Explore the limestone cracks and crevices for pipefish, banded coral shrimp and colourful nudibranchs.
Maximum depth: 30 m
Difficulty level: Intermediate to advanced — currents can be mild to strong and conditions may change. Your guide will select the safest entry and exit points.
Since 2018, Koh Tachai has been closed to tourism to allow nature to recover from heavy visitation and damage to shallow coral near the beach.
Divers can still explore the offshore Koh Tachai Pinnacle, where marine life has continued to thrive and the coral is even better than before.
A negative entry is recommended to descend quickly in challenging currents. Sheltered areas on the bottom make the dive manageable, while staying mid-water in the current can make for a very short dive.
The west and north sides feature beautiful coral gardens visited by hunting trevallies, barracudas, giant manta rays and whale sharks.
Two additional pinnacles to the north feature some of Thailand’s most beautiful coral, but the area is too large to explore fully in one dive.
With spectacular coral, abundant marine life and challenging currents, Koh Tachai Pinnacle is best suited to intermediate and advanced divers. A negative entry may be required.
Maximum depth: 30 m
Difficulty level: Intermediate to advanced — currents can be strong and challenging.
Continue your exploration towards Surin National Park in the North…
The Similan Islands National Park. The Similan Islands (Thai: หมู่เกาะสิมิลัน, RTGS: Mu Ko Similan, Thai pronunciation: [mùː kɔ̀ʔ si.mi.lan]) is an archipelago in the Andaman Sea off the coast of, and part of, Phang Nga Province in southern Thailand. It was established as Mu Ko Similan National Park in 1982 by the Forestry Department.
Getting there: only reachable by boat
Depth: 10 to 40 m
Current: Mild to strong
Water temperature: 26 to 30°C
Dive type: Reef dive (boulder or walls)
Visibility: up to 30 m
Diving period: November to April
Location: 70 km West of Phangna Province
The Similan Archipelago consists of eleven islands:
From north to south:
Koh Huyong
Koh Payang
Koh Payan
The waters surrounding Islands 1, 2 and 3 are protected areas reserved for sea turtle nesting and are off-limits to tourists.
4–5. Koh Meang & Koh Ha
Two connected islands where the national park has established its headquarters.
Koh Payoo
Koh Hua Kalok (also known as Koh Hin Pousar)
Koh Similan (the largest island)
Koh Ba-Ngu (home to the Christmas Point dive site)
10–11. Koh Bon (also known as Koh Talu) and Koh Tachai were incorporated into the national park somewhat later. Today, they are considered among the best dive sites in the Similan Islands.
The name “Similan” actually comes from the Yawi (the local native dialect) word for “nine” to name the cluster of 9 nearby islands in the South.
All the islands are located within Mu Ko Similan National Park, which covers more than 140 km². This beautiful and vast marine national park is well known to divers from around the world. Located approximately 70 km offshore from Phang Nga Province, it is home to gently shaped granite islands that are as impressive above the water as they are beneath the turquoise waters of the Andaman Sea. Covered in tropical rainforest, the islands are fringed with dazzling white beaches and surrounded by coral reefs.
Coral bleaching and tsunamis have damaged some of the hard corals, but soft corals are still abundant, and the marine life remains diverse and plentiful. The Similan Islands therefore remain a beautiful and popular destination for divers of all levels.
The Similan Islands are particularly renowned for their rich coral reefs, which support an exceptional variety of marine life. Divers and snorkellers can encounter many marine species, including manta rays, sea turtles and sea snakes, as well as various pelagic species and, with a little luck, a whale shark.
Beyond their underwater treasures, the Similan Islands are also home to numerous terrestrial species and birds. They are internationally recognised for the beauty and preservation of their natural environments, both above and below the water.
Unfortunately, the islands have suffered from excessive tourism. Up to 7,000 visitors per day were recorded during the 2017–2018 season. In 2018, park authorities therefore decided to limit the number of visitors to 3,325 people per day.
Visitors must now obtain a permit in advance. Your tour operator can arrange this for you using the information provided on your passport.
Located northwest of Koh Hua Kalok (Island No. 7), next to the famous Deep Six dive site.
Start on the west side above a coral nursery at 10–12 m, with schools of angelfish and snapper among hard and delicate corals.
Zigzag between granite rocks and channels at 25–28 m, surrounded by huge gorgonian sea fans. Look for mantis shrimp, moray eels, yellow-spotted pipefish and Durban dancing shrimp.
As you ascend, watch for tornado-like barracuda formations and turtles in the blue. Sunlight on the western side makes West of Eden an excellent midday or evening dive.
Maximum depth: 28 m
Difficulty level: Beginner-friendly, but divers must be certified. Open Water courses are not permitted in Similan National Park.
From the boat, this pinnacle resembles the head of a giant elephant swimming towards you — complete with imagined nostrils!
Located between Koh Hua Kalok and Koh Similan (Islands No. 7 and 8), it features a maze of granite boulders, channels, cracks and swim-throughs from 12 to 30 m.
Start on the south side with a negative entry if conditions allow, as surface currents can carry you past the site. Regroup in a sheltered area before exploring the rocks, channels, cracks and valleys.
Look for lionfish near giant sea fans, moray eels in rocky holes, blue-spotted stingrays on sandy patches, shy seamoths and reef sharks in the blue.
Maximum depth: 30 m
Difficulty level: Intermediate to advanced — strong currents and changing conditions. A negative entry may be required.
Koh Bon is one of Thailand’s renowned manta ray sites. This limestone island offers spectacular scenery, drift diving and the chance to see mantas gliding through the blue.
Currents range from mild to strong, so your guide will choose the best entry and exit points.
Koh Bon has two main dive sites: the West Ridge and Koh Bon Pinnacle.
The West Ridge is a well-known manta ray cleaning station, where mantas often glide slowly in the current.
Further north, Koh Bon Pinnacle reaches around 18 m and makes a great first dive for certified deep divers. Zebra sharks are often seen around the pinnacle, and when conditions allow, you can cross through the blue to the West Ridge.
Explore the limestone cracks and crevices for pipefish, banded coral shrimp and colourful nudibranchs.
Maximum depth: 30 m
Difficulty level: Intermediate to advanced — currents can be mild to strong and conditions may change. Your guide will select the safest entry and exit points.
Since 2018, Koh Tachai has been closed to tourism to allow nature to recover from heavy visitation and damage to shallow coral near the beach.
Divers can still explore the offshore Koh Tachai Pinnacle, where marine life has continued to thrive and the coral is even better than before.
A negative entry is recommended to descend quickly in challenging currents. Sheltered areas on the bottom make the dive manageable, while staying mid-water in the current can make for a very short dive.
The west and north sides feature beautiful coral gardens visited by hunting trevallies, barracudas, giant manta rays and whale sharks.
Two additional pinnacles to the north feature some of Thailand’s most beautiful coral, but the area is too large to explore fully in one dive.
With spectacular coral, abundant marine life and challenging currents, Koh Tachai Pinnacle is best suited to intermediate and advanced divers. A negative entry may be required.
Maximum depth: 30 m
Difficulty level: Intermediate to advanced — currents can be strong and challenging.
Continue your exploration towards Surin National Park in the North…
Explore the Surin Islands, Richelieu Rock and the Similan Islands.
Prices in Thai baht (THB), per diver. The 10% discount is already applied.
