Dive area · Thailand
Koh Taoเกาะเต่า
Use Koh Tao as the regional benchmark: one of the busiest and cheapest places in the world to learn, with sheltered shallow sites for training and two deep pinnacles (Chumphon Pinnacle and Sail Rock) that bring whale sharks in spring and autumn; go March–September, avoid November–December, and choose the shop on instructor ratios and safety, not on the fixed-looking course price.
Map to the area
Add your hotel to get directions from it. · stays in this browser; shared with the pocket card.
Sites
7
4 for Open Water or below
Depth
3–40 m10–131 ft
Water
27–31°C81–88°F
through the year
Best months
Mar–May, Aug–Sep
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At a glance
- Area
- Koh Tao and the Chumphon archipelago, Gulf of Thailand
- Levels
- Try dive to Advanced
- Depth
- 3–40 m10–131 ft
- Visibility
- 5–30 m16–98 ft
- worst to best month
- Best months
- Mar–May, Aug–Sep
Koh Tao, a small island in the Gulf of Thailand north of Koh Samui and Koh Phangan, certifies a huge number of new divers every year. The island's bays offer calm training water, and the offshore pinnacles have real depth, schooling fish and the chance of a whale shark. For Vietnamese dive areas it is the useful comparison: better visibility than Nha Trang or Phú Quốc, more choice than Côn Đảo, but far more divers in the water.
Decide
Which sites suit your level, which months, and what you will see
At a glance
Fine for new divers
Why go
- Training at scale: many shops, many languages, fixed schedules and quick course starts.
- Chumphon Pinnacle and Sail Rock for deeper, fishier dives, with whale sharks some seasons.
- Diving most of the year on one side of the island or the other.
Dive sites
| Site | Depth | Level | Current | Highlights |
|---|---|---|---|---|
| Japanese Gardens (Koh Nang Yuan) | 3–12 m10–39 ft | Try dive | None | Shallow hard and soft coral; training and snorkelling. |
| Twins | 5–18 m16–59 ft | Open Water | Mild | Two granite mounds; training site with reef fish and anemones. |
| White Rock | 5–22 m16–72 ft | Open Water | Mild | Boulders and coral; night dives. |
| Shark Island | 5–25 m16–82 ft | Open Water | Moderate | Soft coral, turtles sometimes; current on the outer side. |
| HTMS Sattakut wreck | 18–30 m59–98 ft | Advanced | Mild | Former navy ship sunk as an artificial reef; guns on deck. |
| Chumphon Pinnacle | 14–36 m46–118 ft | Advanced | Moderate | Granite pinnacle with anemone fields, batfish, barracuda; whale sharks some seasons. |
| Sail Rock | 5–40 m16–131 ft | Advanced | Moderate | Rock pillar between Koh Tao and Koh Phangan with a vertical chimney; big schools; whale sharks. |
Levels are a guide: Snorkel — mask and fins from the surface; no certification; Try dive — uncertified first dive with an instructor, usually to 12 m or less; Open Water — entry certification; recreational limit about 18 m; Advanced — advanced certification; deeper than 18 m or some current; Experienced — advanced plus many logged dives; strong current, blue water, deep. Your guide decides on the day.
Season, visibility and water temperature
- JanGo10–20 m33–66 ft vis
27–28°C81–82°F - FebGo10–20 m33–66 ft vis
27–28°C81–82°F - MarBest15–25 m49–82 ft vis
28–29°C82–84°F - AprBest15–30 m49–98 ft vis
29–30°C84–86°F - MayBest15–30 m49–98 ft vis
29–31°C84–88°F - JunGo10–25 m33–82 ft vis
29–30°C84–86°F - JulGo10–25 m33–82 ft vis
29–30°C84–86°F - AugBest15–30 m49–98 ft vis
29–30°C84–86°F - SepBest15–30 m49–98 ft vis
29–30°C84–86°F - OctCaution8–20 m26–66 ft vis
28–29°C82–84°F - NovAvoid5–12 m16–39 ft vis
27–28°C81–82°F - DecCaution5–15 m16–49 ft vis
27–28°C81–82°F
- JanWind easing after the monsoon
- MarWhale shark season starts
- AprCalm and clear
- JulSouth-west winds; west-side sites choppier
- SepWhale sharks some years
- OctMonsoon approaching
- NovNorth-east monsoon; ferries cancelled some days
- DecRough early in the month, improving
Marine life calendar
| What | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Whale sharks (Chumphon Pinnacle, Sail Rock)Mar–May, Sep–Oct · Never guaranteed; sightings vary a lot by year. | no | no | yes | yes | yes | no | no | no | yes | yes | no | no |
| Barracuda and batfish schoolsAll year | yes | yes | yes | yes | yes | yes | yes | yes | yes | yes | yes | yes |
| Hawksbill and green turtlesAll year | yes | yes | yes | yes | yes | yes | yes | yes | yes | yes | yes | yes |
| Juvenile blacktip reef sharks in shallow baysApr–Aug | no | no | no | yes | yes | yes | yes | yes | no | no | no | no |
Arrive & move
Where the sites are, snorkelling, and how to get there
Site sketch map
- 1Japanese Gardens (Koh Nang Yuan) · Dive site≈10.117, 99.8133–12 m · Try dive10–39 ft · Try diveMap ↗
- 2Twins · Dive site≈10.115, 99.8105–18 m · Open Water16–59 ft · Open WaterMap ↗
- 3White Rock · Dive site≈10.100, 99.8205–22 m · Open Water16–72 ft · Open WaterMap ↗
- 4Shark Island · Dive site≈10.060, 99.8455–25 m · Open Water16–82 ft · Open WaterMap ↗
- 5HTMS Sattakut wreck · Dive site≈10.088, 99.81318–30 m · Advanced59–98 ft · AdvancedMap ↗
- 6Chumphon Pinnacle · Dive site≈10.150, 99.79514–36 m · Advanced46–118 ft · AdvancedMap ↗
- 7Sail Rock · Dive site≈9.950, 99.9705–40 m · Advanced16–131 ft · AdvancedMap ↗
Snorkelling instead
Japanese Gardens (Koh Nang Yuan)
The classic shallow reef; go early before tour boats.
Shark Bay (Thian Og)
Juvenile blacktip reef sharks and turtles in shallow water; do not chase them.
Aow Leuk and Tanote bays
Easy beach entries on the east coast.
Getting there
From Bangkok
Overnight train or bus to Chumphon, then catamaran; or fly to Chumphon or Koh Samui and take a boat.
9–12 h overland
Open the page →
From Koh Samui
High-speed catamaran via Koh Phangan.
1.5–2 h
From Chumphon
High-speed catamaran from the mainland pier.
1.5–2 h
Practical
Picking a safe operator, fees and rules, the chamber, and diving lightly
How to choose an operator
Koh Tao has dozens of dive schools and course prices that look almost identical. What differs is class size, instructor experience and how carefully boats are run.
- 1Ask the maximum students per instructor for your course (four or fewer is good) and whether the same instructor stays with you throughout.
- 2Check the instructor's current professional status with the agency (PADI, SSI or RAID) online.
- 3The boat carries oxygen and first aid, and the shop can name its evacuation plan and chamber.
- 4Gear is serviced and fitted; tanks are checked in front of you.
- 5Deep pinnacles are run with a surface marker buoy for each buddy pair and a clear turn pressure.
- 6Your insurance covers diving to your planned depth; ask whether the shop sells cover if yours does not.
We do not rank or name dive shops. Reviews change with staff; these checks do not.
Marine park fees and prices
| Item | Range | Per | Note |
|---|---|---|---|
| Open Water course (3–4 days) | THB 11,000–15,000 (≈ US$350–500) | person | Accommodation discounts common during courses. |
| Fun dive (local site) | THB 900–1,500 | dive | — |
| Sail Rock day trip (2 dives) | THB 2,500–4,000 (≈ US$80–130) | person | — |
| Koh Nang Yuan landing fee | THB 100–250 | person | Plastic bottles and fins on the beach are banned there (check). |
Ranges, not quotes: fees change without notice. Check with the park or your operator · checked Sep 2026.
- Moorings
- Dive sites use mooring buoys; boats should not anchor on reef.
- No gloves or touching
- Many sites ask divers not to wear gloves; hands off coral and animals.
- Whale sharks
- Keep at least 3–4 m away; no touching, no chasing, no flash.
Nearest hyperbaric chamber
Ask your operator — check
Safety
Deep pinnacles and current medium
Scooter crashes on steep island roads high
Monsoon sea state medium
Responsible diving
- Get your buoyancy right in training before you go near the reef; Koh Tao's shallow sites are worn by heavy use.
- Support shops that take part in reef clean-ups and coral restoration projects, and ask what they do.
- Use reef-safe sunscreen and a rash vest.
- Never touch or ride turtles; report boats that crowd whale sharks.
Questions people ask
Should I learn in Koh Tao or in Vietnam?
Koh Tao has more choice, better visibility and more course start dates; Nha Trang is cheaper and quieter. Either works; pick the shop carefully.
When can I see whale sharks?
Most reports come in March–May and September–October, at Chumphon Pinnacle and Sail Rock. Some years bring many, some almost none.
Can Open Water divers go to the pinnacles?
Sail Rock and Chumphon Pinnacle have shallower sections, and shops take Open Water divers to 18 m there, but you get far more from them with Advanced.
Deep dive
Every source; conditions and fees change, so check before you go
Sources
- secondaryWikivoyage — Ko Tao
- officialTourism Authority of Thailand — Koh Tao
- secondaryWikipedia — Ko Tao