Reef
down to 7 m
Chaweng Reef (Ao Chaweng)
Shallow shore-entry lagoon reef on Chaweng beach, Koh Samui, used for dive training and snorkelling (max 7 m).
- Open Water
Koh Samui & Koh Phangan
Diving in Thailand
12 documented dive sites, 10 of them for Open Water divers. Known for stingrays, barracuda and cuttlefish.
- Best months
- Mar–Apr, Jun–Aug
- Water
- 28–30 °C
- Levels
- Open Water, Advanced
- Nearest airport
- USM
When to go
Pick a month: the diving season, from published sources, and the typical weather.
Pick a month
- Best
- Good
- Possible
- Closed
- Not documented yet
Koh Samui & Koh Phangan in October
Good season- Sea
- 30 °C
- at the surface
- Air
- 29 °C
- 25 °C at night
- Rain
- 230 mm
- one of the wettest months
- Wind
- 9 km/h
- on average
Typical weather, not a forecast: averages for 2021–2025 (air, rain, wind) and 2023–2025 (sea), data from Open-Meteo (ERA5 / Copernicus, Météo-France). Covers an area of roughly 10 to 25 km around the destination.
Ang Thong NMP (thainationalparks.com): main diving season Feb–Oct, clearest Mar–Apr, park usually closed 1 Nov–15 Dec in the monsoon. Wikipedia: heaviest rain mid-Oct to early Dec on Samui. Wikivoyage: best Jun–Aug, diving possible virtually all year. Nov–Dec is shown as possible (not closed) because local Phangan sites remain diveable; Jan is shown as possible as it is outside the Ang Thong main season. Wikivoyage is a weaker source; showing Jun–Aug as best rests on it alone.
Dive sites in Koh Samui & Koh Phangan
From the easiest to the most demanding. Levels with a dashed outline are estimates we are still verifying.
Open Water friendly
usual dive down to 18 m10 sitesReef
down to 14 m
Haad Salad
Shallow west-coast bay once used as a hideout by Malay pirates, with a healthy coral reef reachable from the beach.
- Open Water
- Turtles
Reef
down to 24 m
Koh Ma
- Open Water
- Turtles
Reef
down to 18 m
Koh Tae Nai
- Open Water
Reef
down to 20 m
Koh Tae Nok
- Open Water
Reef
down to 22 m
Mae Haad
- Open Water
- Whale sharks
For Advanced divers
usual dive down to 30 m2 sitesMarine life
When the big encounters happen, month by month.
Reported here, season not documented yet:
- Stingrays
- Barracuda
- Cuttlefish
- Octopus
- Squid
- Clownfish
- Groupers
- Whale sharks
- Reef sharks
- Turtles
- Trevally
- Seahorses
- Moray eels
- Sea snakes
Where is Koh Samui & Koh Phangan?
- Nearest airport
- USM
Koh Samui & Koh Phangan: frequently asked questions
- When is the best time to dive Koh Samui & Koh Phangan?
- The best months to dive Koh Samui & Koh Phangan are Mar–Apr, Jun–Aug. Ang Thong NMP (thainationalparks.com): main diving season Feb–Oct, clearest Mar–Apr, park usually closed 1 Nov–15 Dec in the monsoon. Wikipedia: heaviest rain mid-Oct to early Dec on Samui. Wikivoyage: best Jun–Aug, diving possible virtually all year. Nov–Dec is shown as possible (not closed) because local Phangan sites remain diveable; Jan is shown as possible as it is outside the Ang Thong main season. Wikivoyage is a weaker source; showing Jun–Aug as best rests on it alone.
- Is Koh Samui & Koh Phangan good for beginner divers?
- Yes, partly: 10 of the 12 dive sites we document are suited to Open Water divers, including Chaweng Reef (Ao Chaweng), Haad Salad and Haad Yao House Reef. The others need more experience or a higher certification.
- What is the water temperature in Koh Samui & Koh Phangan?
- The water is usually between 28 °C and 30 °C over the year.
- What marine life can you see in Koh Samui & Koh Phangan?
- Divers regularly see stingrays, barracuda, cuttlefish, octopus, squid and clownfish.
- How do you dive Koh Samui & Koh Phangan?
- The nearest airport is USM.
About this page
Seasons and marine life come from the sources below. Site levels and depths marked as estimated come from our original catalogue and are being checked one by one. Conditions change: always confirm with a local dive centre.
Your next dive is somewhere out there.
Find my next dive tripPhoto credits
- Sunlight and bubbles in deep blue water, Sarah Lee, Unsplash License, on Unsplash