Andaman Sea
Diving in Thailand
Thailand's best diving is in the Andaman Sea, north of Phuket. The Similan Islands are built of enormous granite boulders that stack into arches and swim-throughs unlike the coral architecture elsewhere in the region, and further north Richelieu Rock — a lone limestone pinnacle in open water off the Surin Islands — is the country's most reliable whale shark and manta site. Both are national park waters, which matters practically: the park closes for roughly five months a year and the sites are reached almost exclusively by liveaboard.
Where to dive in Thailand
What you can see
Know before you go
- Best season
- November to May. The marine park closes to visitors from roughly mid-May to mid-October each year, so the season is fixed by regulation rather than weather.
- Conditions
- Water 27–30°C and generally calm in season, with visibility 15–30 m that drops sharply when plankton blooms — which is exactly when the whale sharks turn up.
- Getting there
- Fly to Phuket (HKT). Liveaboards leave from Khao Lak or Tap Lamu, a 60–90 minute transfer north of the airport. Day boats reach the closer sites; the Similans and Richelieu really want a multi-day trip.