Thailand is one of the most accessible diving destinations in Southeast Asia: centres everywhere, courses at every level, and two seas with very different characters.
Two seas, two seasons
The west coast, the Andaman Sea, dives from November to April. The east coast, the Gulf of Thailand, rather from May to September. This is the first decision: by month, you do not dive the same sea.
The Similans
The most famous site: granite islands, rich reefs, often excellent visibility and the chance of manta rays. Access from Khao Lak by day trip or liveaboard. The park closes during the monsoon, generally mid-May to mid-October.
Richelieu Rock
An isolated rock pinnacle, considered one of the country’s best sites, reached by liveaboard from Khao Lak or Ranong. Exposed: conditions can be harder.
Koh Lanta and Phi Phi
Accessible diving and courses, with varied sites: reefs, wrecks, walls. Many centres, competitive prices, good for beginners.
Koh Tao
In the Gulf, one of the world’s training capitals: hundreds of centres, low prices, warm water. The downside is crowds: choose a serious centre and dive early.
Pattaya and wrecks
Less known, with wrecks and practical sites for divers based in Bangkok. A useful option outside the west-coast season.
Training
Courses are offered everywhere. Choose a centre limiting students per instructor and never sacrificing safety for volume.
Liveaboard or day trip
A liveaboard reaches distant sites and dives several times a day. A day trip suits discovery, with two or three dives.
Prices
Affordable: a day trip costs less than in Europe. Beware of very low prices: they can hide thin supervision or tired gear.
Gear
Most centres rent full equipment. If you dive regularly, bring at least your mask, computer and light wetsuit.
Wildlife
The Andaman offers turtles, reef sharks, rays and corals; the Gulf is more accessible. Encounters remain unpredictable: no serious operator guarantees an animal.
Safety
Check the instructor’s certification, oxygen on board, insurance cover and emergency procedures. Dive within your level.
FAQ
Do I need certification?
No: you can start with a supervised discovery dive.
Best season?
Andaman November to April, Gulf May to September.
Cost of a dive?
Less than in Europe.
Dive without swimming?
No, swimming is a basic safety condition.
Children?
Some programmes start at eight or ten.
Also read
To go further
Mr Schaka’s guidebook, Phuket and the Andaman Sea – The Practical Guide, covers the essentials: transport, neighbourhoods, addresses, food, etiquette and safety, updated for 2026–2027.
