Liveaboard Diving in Koh Tachai

What To Expect On A Koh Tachai Liveaboard

Liveaboards to Koh Tachai usually visit this area on a Similan Islands itinerary on theri way to Richelieu Rock. It's only 12 square kilometers in size and located on the northwest of Similan Islands National Park, it actually lies between the Similan and Surin Islands. An idyllic location in the Andaman Sea, this small uninhabited island is formed of lush rainforest, stunning white sandy beaches and crystal clear waters. Relatively untouched Koh Tachai is still unspoilt and worth the visit on your liveaboard dive cruise. Below the surface, some other visitors include whale sharks, manta rays, leopard sharks and Napoleon wrasse to name just a few. The waters around the island are quite shallow towards the shore then drops off suddenly to depths of 70 metres. Acting like a barrier, these drop offs protect the island and the rich waters around it offer excellent snorkeling.

What You Can See

There are two great dive sites at Koh Tachai, the plateau to the south and the eastern reef. Off the eastern coast, the sheltered shallower waters make for good night dives. Most liveaboards will moor here for the night.

Koh Tachai plateau, about 1km south east of the island, is so named because it is ringed by a ridge like coral plateau crowned with hard corals, gorgonian sea fans line the scattered boulders, sloping from 12 - 35 m to the sandy bottom where leopard and nurse sharks lie peacefully undisturbed. Groups of snapper lurking on the top ledges, octopus hiding amongst the corals, under which red banded cleaner shrimp work tirelessly. It is best to pay close attention to the divemaster's brief as this site can be challenging at times although the swim-throughs provide shelter from the strong currents. There is a descent line from a buoy on the south side, helping the diver to descend in sometimes strong surface currents. This site is for the more experienced diver. Towards the end of the dive, you may see coral eating Hawksbill turtles, groups of batfish or even the banded sea snake lurking near the mooring line upon your ascent. Keep an eye out for the odd Napoleon wrasse patrolling the area.

Koh Tachai pinnacle is usually done as a drift dive and here the currents bring high levels of plankton, during the months of February - April, and in turn the larger pelagics feeding on them such as the Manta Ray and Whale Shark. The strong currents enable the barracudas, trevallies and sharks to hunt easily for smaller prey. Early morning dives can waken you up from your slumber quite quickly as it can sometimes be a feeding frenzy and you may not know where to look there are so many fish. Visibility varies on the month and the amount of plankton in the water, between 10-30m. If the larger pelagics are not on show then be on the lookout for the macro life. Small frogfish and nudibranch are known to grace these waters.

An impressive underwater topography mixed with a diverse marine life make Koh Tachai a must for Surin or Similan cruises.

Getting There

The best way to get to Koh Tachai is on a Thailand liveaboard trip to the Similan or Surin Islands, which will depart from either Phuket or Khao Lak. Further from Phuket than from Khao Lak, (200 km north of Phuket and 80 km northwest of Khao Lak), it is worth checking what port you prefer to depart from. Khao Lak is about 100km north of Phuket and can be reached overland. Please check your itinerary before purchasing flight tickets. There are international flights into Phuket and / or domestic flights from Bangkok to Phuket. Reachable from Khao Lak in one hour you may find other day boats in the area.


Koh Tachai Diving Reviews

  • 9.1 Superb
  • 80 Verified Reviews
  • 10.0 Exceptional
  • Paul L
  • United Kingdom United Kingdom

A great dive site for the experienced. Strong currents - but strong currents attract huge Travally....

Diving Koh Tachai in October on the Bavaria

  • 8.0 Very good
  • yaqoub Y
  • United Arab Emirates United Arab Emirates

Koh Tachai i fall in love with you. this how can Describe my feelings . i can't forget how i was wave good bay when we was ascent.

Diving Koh Tachai in April on the Hallelujah

  • 8.0 Very good
  • Adam H
  • United Kingdom United Kingdom

Great vis again and also lots of fish life. Some strong currents on some of the sites, not for inexperienced divers. Whaleshark was spotted by another group on one of our dives, i did not see it.

Diving Koh Tachai in April on the Manta Queen 1

  • 9.2 Superb
  • herbert K
  • Austria Austria

Whale shark sighting, what do you want more

Diving Koh Tachai in April on the Manta Queen 7

  • 9.6 Exceptional
  • Matthew S
  • Australia Australia

Lovely, we saw two whale sharks there.

Diving Koh Tachai in April on the Manta Queen 2

  • 9.6 Exceptional
  • ILGUK J
  • South Korea South Korea

We saw whale shark at the dome point. Whale shark!

Diving Koh Tachai in April on the Manta Queen 7

  • 9.6 Exceptional
  • HUIJEA L
  • South Korea South Korea

good place for fun diving.

Diving Koh Tachai in February on the Oktavia

  • 9.2 Superb
  • Martin R
  • Germany Germany

Loved the shadows on the white sand while diving

Diving Koh Tachai in October on the Pawara

  • 9.2 Superb
  • Daniel N
  • Sweden Sweden

Very beautiful dive sites as well teeming with marine life and beautiful healthy coral.

Diving Koh Tachai in May on the Manta Queen 1

  • 10.0 Exceptional
  • Lisa M
  • United States United States

Amazing visibility, diverse dive sites

Diving Koh Tachai in October on the Hallelujah

  • 10.0 Exceptional
  • Norbert D
  • Germany Germany

loads and loads and loads and loads of fish. not even in Australia have they been so plentiful. it is a bit of shame that the Thai people didn't properly take care of these miracles under the sea but the site is still brilliant.

Diving Koh Tachai in April on the Manta Queen 2

  • 10.0 Exceptional
  • Evan R
  • New Zealand New Zealand

Really enjoyed seeing new nudibranches & a magical seahorse. I enjoyed finding some of the smallest critters but also the big Napolean Wrasse & Moray eels.

Diving Koh Tachai in April on the Sawasdee Fasai

  • 8.8 Fabulous
  • Christopher T
  • United States United States

The rock formations underwater make it special.

Diving Koh Tachai in April on the Similan Explorer

  • 9.2 Superb
  • Eric W
  • Singapore Singapore

Koh Tachai got a nice coral garden as well. Saw a Marble ray there.

Diving Koh Tachai in March on the Manta Queen 6

  • 10.0 Exceptional
  • Elles D
  • Netherlands Netherlands

Nice reefs,beautiful rock formations, sometimes current is a factor. Not too busy. Great diversity.

Diving Koh Tachai in March on the Deep Andaman Queen

  • 9.6 Exceptional
  • James C
  • United Kingdom United Kingdom

Really interesting site with lots of different kinds of coral and fish

Diving Koh Tachai in March on the Pawara

  • 10.0 Exceptional
  • Rebecca H
  • United States United States

Another amazing dive. We saw a fleeting glimpse of a manta ray at the end of our dive. Clown triggerfish, lots of barracuda, crown of thorns, lionfish...

Diving Koh Tachai in February on the Manta Queen 1

  • 9.2 Superb
  • Eugene S
  • Canada Canada

This was a very good dive.

Diving Koh Tachai in March on the Dolphin Queen

  • 7.6 Good
  • Juliane H
  • Austria Austria

Other group, saw small whale shark. Special thing for us, stone fish. Good visibility, warm water - nothing to complain

Diving Koh Tachai in March on the Dolphin Queen

  • 8.0 Very good
  • Andrew B
  • United Kingdom United Kingdom

Really good as we saw Manta Rays which was the highlight of our trip

Diving Koh Tachai in February on the Deep Andaman Queen

  • 9.6 Exceptional
  • JAYEON C
  • South Korea South Korea

Interesting to see unique geography.

Diving Koh Tachai in February on the The Junk

  • 9.6 Exceptional
  • Yann B
  • France France

Good at Twin Peaks - much action from Pompanos, yellowtail barracudas. Night dive at Avlek.

Diving Koh Tachai in February on the The Junk

  • 8.8 Fabulous
  • Pablo E
  • Chile Chile

Here is the place we meet the mantas, incredible experience

Diving Koh Tachai in February on the Similan Explorer

  • 8.0 Very good
  • Maria Tereza C
  • Brazil Brazil

Strong current in the First dive. We had to hold the rock during a long time as it was impossible to swim around. Fortunately a big school of barracudas made us company. Second dive was good.

Diving Koh Tachai in February on the Hallelujah Liveaboard

  • 8.8 Fabulous
  • Maillard J
  • France France

The conditions were not so good ( too strong current)

Diving Koh Tachai in February on the Dolphin Queen

  • 7.2 Good
  • Felipe C
  • Brazil Brazil

Good dive site good visibility

Diving Koh Tachai in February on the Deep Andaman Queen

  • 9.2 Superb
  • Franco L
  • Italy Italy

Beside some strong corrent, nice

Diving Koh Tachai in February on the Manta Queen 6

  • 8.4 Very good
  • Noel H
  • United States United States

Good - lots of fish and some fun drift diving.

Diving Koh Tachai in February on the Hallelujah

  • 8.4 Very good
  • Chris G
  • Singapore Singapore

Good, no large fishes, but plenty of marine life

Diving Koh Tachai in January on the Similan Explorer

  • 10.0 Exceptional
  • Jia S
  • China China

Currents are tricky but lots of fun!

Diving Koh Tachai in January on the Hallelujah Liveaboard

  • 9.2 Superb
  • Shiou H
  • United States United States

The world underwater is simply breathtaking! It was an adventure diving with current, waves, and surge

Diving Koh Tachai in January on the Thai Sea

  • 10.0 Exceptional
  • Todd H
  • United States United States

Beautiful landscape with huge sea fans and starfish. Teaming with fish and life. Strong current.

Diving Koh Tachai in January on the MV DiveRACE Class E

  • 10.0 Exceptional
  • Benjamin B
  • United States United States

Amazing. So much coral and beautiful marine life

Diving Koh Tachai in December on the Manta Queen 3

  • 9.6 Exceptional
  • David G
  • United States United States

Amazing, could see so many fish and awesome coral.

Diving Koh Tachai in December on the Dolphin Queen

  • 7.6 Good
  • Sandra K
  • Germany Germany

Very very nice. The best with Richelieu Rock

Diving Koh Tachai in November on the Diva Andaman

  • 7.2 Good
  • Miranda M
  • Netherlands Netherlands

nice places with nice coral lots of different fishes

Diving Koh Tachai in November on the Deep Andaman Queen

  • 10.0 Exceptional
  • Sarah H
  • United States United States

visibility wasn't great, but we saw choke manta ray....absolutely incredible

Diving Koh Tachai in April on the Deep Andaman Queen

  • 10.0 Exceptional
  • Raymond C
  • United Kingdom United Kingdom

Unfortunately no big pelagics but the usual suspects were in abundance Great diving

Diving Koh Tachai in March on the Deep Andaman Queen

  • 9.2 Superb
  • Richard C
  • United States United States

I'm sure it's not the norm, but safety stop in a school of barracdas! Way too awesome!!!!

Diving Koh Tachai in February on the Deep Andaman Queen

  • 8.8 Fabulous
  • Farhan R
  • Australia Australia

Visibility was not as good as others but that could just be bad luck on that day

Diving Koh Tachai in January on the Deep Andaman Queen

  • 7.2 Good
  • Daniela G
  • Portugal Portugal

Good, but visibility could have been better.

Diving Koh Tachai in December on the MV DiveRACE Class E

  • 10.0 Exceptional
  • Kal G
  • Israel Israel

a few great spots but poor visibility & a lot of dead reef

Diving Koh Tachai in December on the Diva Andaman

  • 8.0 Very good
  • Joseph F
  • United Kingdom United Kingdom

Nice barracuda schools and fish life

Diving Koh Tachai in December on the Deep Andaman Queen

  • 9.2 Superb
  • John A
  • United States United States

Challenging ripping current but great dive with Giant Manta and dive guide kept us safe.

Diving Koh Tachai in March on the Deep Andaman Queen