The Sail Rock dive site is the ultimate dive experience in the Gulf of Thailand — and every certified diver visiting Koh Tao should experience it at least once. Rising dramatically from the open ocean between Koh Tao and Koh Phangan, this isolated pinnacle delivers an exceptional underwater world: extraordinary fish density, a legendary natural chimney, and regular whale shark encounters. Indeed, the Sail Rock dive site is in a league of its own. At The Divers Boat, we run dedicated fun dive trips here on our blue boat, exclusively for certified divers. Furthermore, we are the only centre to offer daily departures to Sail Rock from both Koh Tao and Koh Phangan.
Depth range
From Koh Tao
From Koh Phangan
Visibility
Advanced recommended
Fun dive only
Natural chimney
Blue water diving
Why Sail Rock dive site is the best in the Gulf of Thailand
The answer comes down to one word: isolation. The Sail Rock dive site is a pinnacle that rises directly from the open ocean, far from any coastline. Thanks to this unique configuration, large fishing vessels cannot trawl the area — which means marine life has developed freely for decades, largely undisturbed by human activity. According to Wikipedia, it is consistently ranked among the top dive sites in Southeast Asia.
As a result, this pinnacle concentrates fish in extraordinary densities: barracuda in tight formation, giant trevallies, snappers, groupers, stingrays. And during favourable periods, the whale shark — the largest fish on the planet. Our team has experienced the incredible privilege of encountering two whale sharks simultaneously on a single dive here.
The Sail Rock dive site chimney — a once-in-a-lifetime experience
Beyond the marine life, the Sail Rock dive site offers something entirely unique in the Gulf of Thailand: a natural vertical chimney that passes straight through the rock. You enter at 16 metres depth and ascend progressively to 5 metres, surrounded by fish and bathed in light filtering down from the surface above.
Swimming through this passage is, without doubt, one of the most extraordinary underwater experiences in all of Southeast Asia. Furthermore, for divers who want to explore beyond the chimney, the maximum depth of the site reaches 40 metres, making it an excellent choice for Advanced Open Water divers looking to push deeper. Read the full story of this dive, and everything else Sail Rock has to offer, in our complete Sail Rock guide.
Marine life: what you’ll encounter
This is one of the rare dive sites in the Gulf of Thailand where large pelagic encounters are a genuine possibility on every dive. In addition to the permanent residents — groupers, snappers and trumpetfish tucked into the rock’s crevices — several species gather here in impressive numbers. Moreover, the whale shark makes this one of the most celebrated sites in Southeast Asia.
- Barracuda in dense schools
- Giant trevally hunting in current
- Groupers & snappers in crevices
- Stingrays on the sandy bottom
- Trumpetfish & batfish
- Whale shark (year-round)
Whale shark sightings are possible year-round, with peak periods from March to May and October to December. Because this is an isolated pinnacle where industrial fishing is impossible, marine life has thrived undisturbed — which is precisely why it attracts the largest fish on the planet with such regularity.
What level do you need?
The minimum certification required is Open Water (OW): the chimney between 5 and 16 metres is fully accessible to all OW certified divers, and the marine life at these depths is already outstanding. However, to explore the deeper zones — particularly the 40-metre base of the rock — an Advanced Open Water (AOW) certification is strongly recommended.
Moreover, this site is an ideal environment for specialty courses such as Deep Diver or Underwater Photography. Feel free to speak with The Divers Boat team about combining a specialty with your fun dive trip to this exceptional site.
Our advantage: staggered departures for a better dive
Crowds can quickly ruin the experience at a popular site. At The Divers Boat, we deliberately schedule our departures at staggered times compared to other boats. By arriving as the other groups are leaving, we ensure fewer divers in the water, more undisturbed marine life, and an altogether better dive.
Our blue boat is exclusively dedicated to certified divers — no mixing with beginners, no compromises on exploration quality. Every diver on board holds at minimum an Open Water certification, which ensures group cohesion and allows us to make the most of every minute underwater. In addition, we limit groups to a maximum of 4 divers per guide.
Dive the Sail Rock dive site from Koh Tao or Koh Phangan
The Divers Boat organises fun dive trips to the Sail Rock dive site from Koh Tao, departing from Mae Haad — the island’s main pier. The journey takes approximately 2 hours. In addition, we also run a dive centre in Chaloklum, Koh Phangan, with its own dedicated boat. From there, the crossing takes just 1 hour 15 minutes — 45 minutes less than from Koh Tao.
Furthermore, our Koh Phangan centre offers all SSI courses from Try Scuba to Divemaster, as well as regular fun dives from Koh Phangan. Check our fun dive prices for all available options. If you’re deciding between the two departure points, our Koh Tao vs Koh Phangan comparison breaks down the travel time, schedule and trip type for each.
Our Sail Rock trips — days, times and prices
Sail Rock is a full-day, open-ocean trip, and the programme changes with the day of the week. These are our actual departures, from all three starting points.
| Departure | Trip | Days | Times | Price |
|---|---|---|---|---|
| Koh Tao (Mae Haad) | Double Sail Rock — 2 dives on the site | Tue, Thu, Fri, Sun | 11am → 6pm | 3,200 THB |
| Koh Tao (Mae Haad) | Ultimate 3S — Southwest Pinnacle, Sail Rock, Shark Island | Mon, Wed, Sat | 9am → 6pm | 3,900 THB |
| Koh Phangan (Chaloklum) | Double Sail Rock — 2 dives | Every day | 9:30am → 4pm | 3,200 THB |
| Koh Samui (via Koh Phangan) | Double Sail Rock — 2 dives, ferry and transfer included | Every day | Ferry 8am → back 5:30pm | 4,800 THB |
From Koh Phangan the crossing is only 1 hour 15 against 2 hours from Koh Tao — and our 9:30am departure is the only one in the Gulf that fits the first Lomprayah ferry from Koh Samui. Full rates on our Koh Tao prices, Koh Phangan prices and Koh Samui day trip pages.
Tips for your Sail Rock dive
Sail Rock is an isolated pinnacle in open water, with no shelter. Three things separate a good dive from one you simply endure.
- The current can be strong. This is an exposed site: depending on tide and wind it ranges from nothing to serious. Your guide decides which way round the rock to go at the moment you enter the water, not before. Stay together and follow the profile given in the briefing.
- The chimney is an entry, not an exit. You go in at 16 metres and come out at 5. In a small group you take your time; behind twenty divers it becomes a traffic jam. That is one of the reasons we leave later than everyone else.
- Save air for the safety stop. You ascend in open water along the line. The best encounters — barracuda schools, trevally, sometimes the whale shark — often happen during those three minutes.
Frequently Asked Questions — Sail Rock Dive Site
What level do I need to dive Sail Rock?
An Open Water SSI certification (or equivalent PADI, CMAS) is the minimum level required to dive Sail Rock. The maximum depth of the site reaches 40 metres — an Advanced Open Water certification is recommended to explore the deeper zones. The chimney, between 5 and 16 metres, is accessible to all Open Water certified divers.
Can you see whale sharks at Sail Rock?
Yes, Sail Rock is one of the best sites in the world to encounter whale sharks. Our team has had the incredible experience of seeing two whale sharks simultaneously on a single dive. Sightings are unpredictable but more frequent from March to May and October to December.
How long does it take to get to Sail Rock from Koh Tao?
The journey from Koh Tao takes approximately 2 hours by boat. From Koh Phangan, the journey is approximately 1 hour 15 minutes. At The Divers Boat, we schedule staggered departures to arrive at the site as other boats are leaving — fewer crowds, more marine life.
What is the Sail Rock chimney?
The Sail Rock chimney is a natural vertical tunnel that passes through the rock. You enter at 16 metres depth and ascend progressively to 5 metres, bathed in light filtering from the surface above. It is one of the most impressive underwater geological formations in the Gulf of Thailand.
Is Sail Rock accessible from Koh Phangan?
Yes. The Divers Boat operates a dive centre in Chaloklum, Koh Phangan, with its own dedicated boat. From Koh Phangan, Sail Rock is only 1 hour 15 minutes by boat — 45 minutes less than from Koh Tao. All SSI courses are available from Koh Phangan, from Try Scuba to Divemaster.
What is the difference between the Double Sail Rock and the 3S trip?
Double Sail Rock is two dives on Sail Rock in the same day (3,200 THB). The 3S trip adds Southwest Pinnacle and Shark Island for three dives (3,900 THB). Take the Double if you want to dive Sail Rock properly; take the 3S if you want the best of the Gulf in one day.
Can you dive Sail Rock from Koh Samui?
Yes. Take the 8am Lomprayah ferry to Koh Phangan, we transfer you to Chaloklum, the boat leaves at 9:30am and you are back on Koh Samui the same evening — 4,800 THB including ferry and transfer. Our 9:30am departure is the only one in the Gulf that makes this possible.
Book your fun dive trip with The Divers Boat — SSI dive centre at Mae Haad, Koh Tao.