6 Koh Tao dive sites you can’t miss & the best time to go

We know you can’t wait to see our top picks for dive sites in Koh Tao. And we promise, you won’t be disappointed! But let us also tell you a bit about the island itself.

If you’ve done a bit of research into scuba diving in Thailand, it wouldn’t have taken you long to come across the island of Koh Tao. Known for it’s easily accessible dive sites suitable for beginners and advanced divers alike, people flock to this tropical paradise to break away from the mainland and experience the ocean environment.

Situated in the Gulf of Thailand, a few hours ferry ride north of Koh Samui, the island is small compared to others nearby, covering a small 21km². It is well known for its tropical coral reefs with a diverse collection of species including sting rays, turtles and, if you are lucky, the majestic whale sharks.

Photo by Dan from Balistidae Imaging

Koh Tao not only boasts an array of dive sites teeming with coral and other marine life. It also has some beautiful sights to explore on land. From jungle hikes to viewpoints, to rock climbing and beach bars galore, Koh Tao has something for everyone.

Koh Tao dive sites are easily accessible by a short boat ride away from the island. Many of these spots offer superb, calm conditions that offer beginner divers a gentle introduction into the world of scuba. Several dive sites with shallow reefs are also ideal for snorkelers. Most dive shops on the island will offer non-divers the opportunity to get a glimpse into the beauty of being underwater.

Photo by Dan from Balistidae Imaging

 

The 6 best dive sites in Koh Tao

 

Sail Rock

Sail Rock is located much further away from the island than other dive sites around Koh Tao. It remains one of the most stunning spots in the Gulf of Thailand.  It’s an impressive pinnacle that breaks the surface of the water. The dive site is extremely easy to navigate underwater. Simply take a circular route around the rock clockwise or anti clockwise.  

It is extremely common to encounter huge schools of fish here, ranging from barracuda to fusiliers. Find yourself in the middle of this and it will blow your mind.  There is often an abundance of giant groupers to spot too but look carefully as, despite their size, they are very well camouflaged! 

Photo by Dan from Balistidae Imaging

Keep your eyes open for the vertical tunnel swim through at around 6 meters. It will take you down to 18 meters and back out.  Most guides will tell you about this feature in their dive briefing.

It is an incredibly varied ecosystem that must be on your bucket list when visiting Koh Tao.

Level: Experienced (small currents can be present)

Max Depth: 0-45 meters

Marine Life: barracuda, trevally, giant groupers, moray eels, banded shrimp, giant clams, whalesharks

Tip: Diving on enriched air is recommended

 

Southwest Pinnacle

Like Sail Rock, Southwest dive site is one of the premier scuba diving sites that Koh Tao has on offer. The beauty of Southwest can be seen by simply looking at its mountain like topography, but underwater.  

It takes approximately 40 minutes to travel to the pinnacle from Koh Tao. Some would say it is this remoteness that encourages its biodiversity.  Divers can find a maximum depth of 30 meters and see its tallest peak almost break the surface.  It really does feel like you are floating around a mountain range.

Another perfect site to see schooling fish, Southwest pinnacle hosts a variety of species including batfish, chevron barracuda, needlefish, squid and groupers.  It is also a well known location for encountering the big blue spotty fish, aka the whaleshark.  The carpet of anemones that cover the tops of the pinnacles are eye-catching appearing in vibrant greens, blues and pinks. And if you get close enough (although not too close!) you will be able to spot their resident anemonefish.

Divers can also explore the “secret” pinnacle, a few minutes swim south east (120°) of the eastern most buoy.  This pinnacle does not appear on the dive maps, but certainly worth a visit if conditions allow and you have plenty of air remaining.

Level: Competent beginner 

Max Depth: 30m

Marine Life: Giant groupers, titan triggerfish, anemonefish, squid, needlefish, batfish, boxer shrimps, whalesharks, blue spotted ribbontail ray, great barracuda, giant moray eel, trevally.

Tip: Diving on enriched air is recommended

 

Chumphon

Sitting about 12 km away from the island, you can find Chumphon Pinnacle, another one of Thailands underwater gems.

With great visibility almost all year round, Chumphon is one more dive site at Koh Tao that should not be missed off your trip.  It comprises of one main pinnacle with a collection of smaller pinnacles running north south.  It is an easily navigable dive site. The tip of the main pinnacle reaches up to 14 metres of the surface, from a depth of 36 metres.  Because the tip of the tallest pinnacle is still 14 metres away from the surface, it makes Chumphon less suitable for Open Water Students and more suitable for those that are trained up to 30 or 40 metres.

Photo by Dan from Balistidae Imaging

Like Southwest, the top of the pinnacles are covered with a beautiful carpet of anemones which move gently in unison with the current.  The site hosts a variety of fish species including giant groupers, scorpion fish and batfish among many more.

Divers have a high chance of bumping into whalesharks here too during the months of March to May and August to October.  However, expect this also to be the busiest months for other divers seeking the same experience!

Also be prepared for the thermocline at around 25 metres which is present most of the year. Expect a drop in temperature and visibility when you encounter this.

Level: Experienced/Advanced (strong current)

Depth: 36 metres

Marine Life: barracuda, bigeye trevally, giant moray eel, batfish, grouper, clownfish, triggerfish, whaleshark, king mackerel.

Tip: Ask your dive guide to lead you to “barracuda rock” (if gas permits), just south of the main pinnacle.  Surprisingly, you are likely to see large schools of barracuda swimming here, an impressive site to say the least.

 

White Rock

Pulling up to White Rock, it is likely you will be able to see White Rock itself as the rock pinnacle almost breaks the surface.  Located a short boat ride on the west of Koh Tao, the dive site consists of two groups of rocks with an area of sand in between.

Photo by Dan from Balistidae Imaging

For a dive spot that is so close to the main island, it boasts a huge range of diversity.  The corals are impressive and attract a lot of interest from passing turtles looking for food and from eels and blue spotted rays looking for a place to hide.  If you pass the south buoy line, you will no doubt be stalked by the yellowtail barracuda.

White Rock is a dive site that offers divers of all levels something to enjoy.  It is a great location for new divers to explore after completing their first two dives within the sheltered, coastal bays of the island.

Level: Beginner/Intermediate

Max Depth: 22m

Marine Life: Moray eel, bannerfish, triggerfish, bluespotted ribbontail ray, grouper, angelfish, butterfly fish, porcupine fish, turtle.

Tip: keep your eyes peeled for the resident Hawskbill who hangs out at White Rock

 

Sattakut Wreck

HTMS Sattakut is one of Thailands best artificial reef wrecks. It is located not too far from the island of Koh Tao. Sattakut was purposely sunk in 2011 by the Thai Department of Marine and Coastal Resources (DMCR) after being stripped of all toxins and hazardous materials.  The vessel was formerly known as USS LCI (Landing Craft Infantry)-739, an ex US World War II Navy Vessel that was commissioned into the Royal Thai Navy in 1947. In fact this ship played a part in one of the most strategic battles of World War II between the USA and Japan.

Photo by Dan from Balistidae Imaging

Since its sinking, the wreck has attracted a whole range of marine species which now call it home.  Here you will see large fusilier, juvenile barracuda, schools of wrasse, rabbit fish and snappers along with the occasional giant groupers.  It has become a thriving artificial ecosystem which is and exciting sight to explore.

Sattakut is a perfect dive site for PADI Advanced wreck dive and Wreck Specialty students. The wreck sits at approximately 30 metres with the captains cabin (the shallowest section) located at around 18 metres.

Photo by Dan from Balistidae Imaging

Level: Advanced and higher (Wreck Specialty required for penetration)

Max Depth: 30 metres

Marine Life: Giant grouper, sweetlips, snapper, butterfly fish, Jenkins whip tail ray, spotted trout

Tip: Look out for the Jenkins whip tail ray at the bottom of the western side of the ship, between the sea bed and the keel.  Take a good torch with you!

 

Twins

Twins is a dive site that has almost perfect conditions all year around. This makes it extremely popular with divers of all levels.  It consists of two identical rock formations appearing out of the sand with a smaller pinnacle located nearby but slightly deeper.

Photo by Dan from Balistidae Imaging

Although this is a dive site that offers a lot of marine life to spot, make sure you go and visit the saddleback anemone fish, just south east of the main pinnacle. However, make sure you don’t get too close! Divers have built an exclusion zone of several feet around the nest using rocks so please stay outside of this!

Photo by Dan from Balistidae Imaging

Turtles often visit Twins, with banded sea snakes and yellow boxfish often making an appearance.  Twins is also a great place for those interested in the macro life – with nudibranchs galore, gobys, shrimps and pipefish.  Keep your eyes peeled in the soft sand that surrounds the pinnacles! Although hard to spot, the pipefish are beautiful when you do.

Level: Beginner – Advanced

Max Depth: 20 metres 

Marine Life: butterfly fish, moray eels, anemone fish, angelfish, blue spotted stingrays, barracuda, turtles, pipe fish, nudibranch, box fish.

Tip: Look out for the small swim through at around 15 metres.

 

Koh Tao dive conditions 

Diving can take place all year round on Koh Tao. This is another reason why it is so popular with tourists. Unlike the Andaman side, the Koh Tao dive sites can be accessed quite easily even during monsoon storms.  The west side of the island is quite calm all year around. It is sheltered from the storms that may batter the East.

Water temperature tends to remain around 29°/84°F all year round and the visibility between 10-20 meters, but sometimes more.

Most of the dive sites have little to no current which make it ideal for people completing their entry level scuba diving courses.  However, the islands’ popularity does mean that the dive sites can be remarkably busy.

 

Best time to dive in Koh Tao

The best months to dive in Koh Tao would be April– August.  The underwater conditions appear to be the very best at this time of year.  The water is super clear and the air temperature sits at a warm 29°C/84°F.  It is also the time of year where the reef life is really active and is the breeding season for many marine species and the surrounding waters are full of nutrients following the monsoon months previous.  

When the water is full of nutrients, you have a good chance of seeing whale sharks.  They come in to feed, often appearing out of the blue and cruising around the dive sites while you just float and observe. 

Photo by Dan from Balistidae Imaging

If you want to ensure your trip to Koh Tao is full of fun, why not coincide your visit with the Swim for Sharks event?  Held every August during Shark Week, Swim for Sharks is an annual community fundraising event in aid of shark conservation, full of excitement, swimming, good food, beach cleans and great music – one not to be missed!

 

About the author

Katie Woodroffe is a PADI Master Scuba Diver Trainer, environmental educator and blogger at Katy Jane Dives. She has worked as an Eco-Instructor on Koh Tao, training dive students and delivering conservation focused events and talks.  A passionate traveler, at home in the water, Katie is also a trustee of shark and marine conservation organization, Shark Guardian.