Cruising grounds and weather
Andaman Sea or Gulf of Thailand
Should I charter on the Andaman coast or in the Gulf of Thailand?
The short answer
Should I charter on the Andaman coast or in the Gulf of Thailand?
The Andaman coast around Phuket has the limestone, the clear water and the national parks, and its season runs November to April. The Gulf of Thailand around Koh Samui runs the opposite cycle, roughly January to September, with its wet season in November and December. If your dates fall between May and October and you want more than Phang Nga Bay, the Gulf is the better answer. If you want the scenery this region is famous for, it is on the Andaman side and you take its season.
The comparison
| Andaman, Phuket | Gulf, Koh Samui | |
|---|---|---|
| Season | November to April | January to September |
| Landscape | Vertical limestone karsts | Rounded granite and forested islands |
| Water clarity | Excellent offshore, green inshore | Good, generally less clear |
| Marine parks | Similan, Surin, Phi Phi, Lanta, Phang Nga | Ang Thong Marine Park |
| Fleet size | Large, with an international visiting fleet | Smaller, mostly local |
| Passages | Long crossings available | Shorter, more sheltered |
The honest recommendation
Most people asking this question have fixed summer dates and want to be told the Andaman works anyway. It partly does, in Phang Nga Bay. But if the point of the trip is the sailing rather than the specific islands, the Gulf in July is a better week than the Andaman in July, and it is not close.
Last checked 6 September 2026. Rates, fees and regulations in this market change every season, so figures on this page are correct as at that date and not afterwards. How the figures are gathered.