Koh Tao
Koh Tao is a small island in the Gulf of Thailand. Thanks to its beautiful underwater scenes and its affordability, Koh Tao has become a scuba diving hub and has certified a lot of scuba divers each year. Also Koh Tao remains a strong option for backpackers during the European summer (July/August) when much of the rest of Thailand is rainy. Fun fact: Roatán in Honduras is another major scuba diving certification hotspot, famous for its section of the Mesoamerican Barrier Reef.
Best Dive Sites Around Koh Tao
Koh Tao offers a mix of shallow bays for beginners and deeper pinnacles for advanced divers.
**Sail Rock** – The most famous site, known for its “chimney” swim-through and chance of whale sharks
Chumphon Pinnacle – Granite formations with barracuda and reef sharks
Southwest Pinnacle – Huge schools of fish and colorful anemones
Shark Island – Coral gardens and frequent shark sightings
HTMS Sattakut Wreck – A sunken navy ship for wreck diving
Most dive sites are 10–60 minutes by boat, making daily trips easy and frequent.
When is the Best Time to Dive?
Koh Tao has year round diving with the water temperature always around 28°C to 30°C (82°F to 86°F)
Best Time (February – April): This is the "true" dry season. The water is flat and crystal clear, making it the prime time for diving and snorkeling.
Secondary Peak (May – August): While the west coast (Phuket/Lanta) gets hit by monsoons, Koh Tao usually stays relatively dry and sunny, though you might get occasional afternoon showers.
Whale Shark Season: Generally March and April, but they are often spotted in September and October as well.
Worst Time (October – December): The Gulf monsoon hits later than the rest of the country. November is typically the wettest month, with rough seas that can make ferry travel and diving difficult.
Should I go to Koh Tao area in Gulf of Thailand or Koh Phi Phi / Koh Lanta area in Andaman sea?
It's actually an easy choice. The answer depends on the time. If you are now in April - October, go to Koh Tao side, if in Nov - April go to Koh Lanta Andaman sea side.
Becasue for Koh Tao area the monsoon is October – early December and for Koh Landa the monsoon season is May – October. And to avoid heavy rain you should just try to avoid the monsoon season.
What can you see diving in Koh Tao?
Koh Tao is home to a wide range of marine life. While the diversity isn’t as vast as some other world-famous dive destinations, it’s still impressive. Here’s just a glimpse of what you can expect:
Whale Sharks: Koh Tao is one of the best places in the world to spot the gentle giant, the whale shark. These peaceful creatures are a bucket-list species for many divers. Although sightings aren’t guaranteed, the chances of encountering a whale shark are relatively high, especially during the dry season (March to May).
Mantas: Manta rays occasionally pass through Koh Tao, especially around Sail Rock, though they are rarer than whale sharks. Seeing a manta glide through the water is truly magical.
Reef Sharks: Blacktip reef sharks, although harmless, are an exciting find for many divers. These sleek predators are often seen cruising the reefs in search of food.
Turtles: Koh Tao’s waters are home to both green sea turtles and hawksbill turtles. These creatures can be spotted in several dive sites, including Shark Bay and Ao Leuk.
Which island should I stay? Koh Tao, Koh Phangan, or Koh Samui?
In our opinion: for luxury resort style, choose Koh Samui. For party and spiritual stuff like yoga, south bath, breathwork etc, choose Koh Phangan. For diving and underwater, choose Koh Tao.
Personally, we loved the north area of Koh Phangan because it is quiet and close to Sail Rock, and you can go hiking into the nature; with a scooter, you can still easily reach the buzzing area to enjoy bars, clubs and nice beach restaurants. Have a look at what's going on in Koh Phangan today and you would already be overwhelmed feeling how spiritual it is.
Top Sites
Trips in Koh Tao
Frequently Asked Questions
What's the most popular dive site in Koh Tao, Thailand?
Chumphon Pinnacle is arguably the most popular and celebrated dive site in Koh Tao, Thailand. It's a massive granite pinnacle located offshore, attracting experienced divers. Its popularity stems from the high chance of seeing larger pelagics like whale sharks (in season), giant groupers, and huge schools of barracuda and trevally. The vibrant coral and anemone coverage makes it a visually stunning deep dive that showcases the best of the Gulf of Thailand's marine life.
What are the good and less popular dive sites in Koh Tao, Thailand?
Well-known sites in Koh Tao, Thailand, include Chumphon Pinnacle, Sail Rock, and Southwest Pinnacle for their pelagic action. For something less crowded but equally impressive, try Green Rock for its unique swim-throughs and triggerfish encounters, or Hin Wong Pinnacle for its beautiful soft corals and macro life. Laem Thian is another great, quieter option offering caves and frequent turtle sightings. These hidden gems provide a more serene diving experience away from the main crowds.
What water temperature is it like throughout the year diving in Koh Tao, Thailand?
Water temperatures in Koh Tao, Thailand, are warm and tropical all year. They typically range from 26-28°C (79-82°F) during the cooler months of December and January. From March to September, the water warms up considerably, averaging a balmy 29-31°C (84-88°F). This consistent warmth makes diving comfortable at any time of year, with only minor fluctuations between seasons.
When is the best time to visit Koh Tao, Thailand?
The best time to dive in Koh Tao, Thailand, is from February to September when conditions are optimal with calm seas and excellent visibility. March, April, and May offer the warmest water and flattest seas. The shoulder months of July to September are also great. The main monsoon season runs from October to December, which can bring wind and reduced visibility, though diving is still possible on sheltered sites. Whale shark season is best from March to May and September to October.
What's the visibility like during the dive season in Koh Tao, Thailand?
During the prime dive season in Koh Tao, Thailand (February to September), underwater visibility is generally very good, often ranging from 15 to 30 meters (50-100 feet), especially at offshore sites like Chumphon Pinnacle. In the monsoon season (October to December), visibility can drop to 5-10 meters due to runoff and rougher seas. However, even during this period, sheltered bays on the island can still offer decent conditions for diving and training.
Are there any seasonal migrations or special events (e.g., manta rays, whale sharks) in Koh Tao, Thailand?
Yes, Koh Tao, Thailand, is famous for its seasonal whale shark sightings. While they can appear any time, the peak seasons are typically March-May and September-October, coinciding with plankton blooms. These gentle giants are most frequently spotted at deeper sites like Chumphon Pinnacle and Sail Rock. Manta ray sightings are much rarer here compared to other parts of Thailand. The island also experiences turtle nesting season on some of its beaches.
What marine life can I expect to see in Koh Tao, Thailand?
Diving in Koh Tao, Thailand, you'll see abundant reef life including moray eels, blue-spotted stingrays, angelfish, butterflyfish, and parrotfish. Larger species are common, such as hawksbill and green turtles, great barracudas, and giant groupers. At deeper pinnacles, look for schools of trevally and fusiliers. Lucky divers might also encounter the majestic whale shark, particularly during peak season. Macro life like nudibranchs and shrimps can also be found by keen-eyed divers.
What thickness wetsuit should I wear in Koh Tao, Thailand?
Given the warm water temperatures year-round in Koh Tao, Thailand, a wetsuit is often optional. Many divers are comfortable in just a rash guard and shorts. For those who get cold easily or for multiple dives, a 3mm shorty wetsuit is more than sufficient for the warmest months (March-September). During the slightly cooler period from December to February, a full-length 3mm wetsuit provides perfect thermal protection without being restrictive.
How do I get to Koh Tao, Thailand?
To reach Koh Tao, Thailand, you must take a ferry. The nearest airports are on the neighboring island of Koh Samui (USM) or on the mainland at Surat Thani (URT) and Chumphon (CJM). From any of these locations, you can take a high-speed catamaran or ferry directly to Koh Tao. The ferry journey typically takes between 1.5 to 3 hours depending on the departure point and vessel type. Book ferry tickets in advance, especially during peak season.
Should I book a liveaboard or stay on shore in Koh Tao, Thailand?
Shore-based diving is the standard and recommended option for Koh Tao, Thailand. The island is small, and all 27 dive sites are easily accessible via short day trips on a longtail or dive boat. This allows you to enjoy the island's vibrant culture, restaurants, and beaches after your dives. Liveaboards are not common or necessary for exploring Koh Tao itself, as they are better suited for more remote, spread-out destinations.