Cruising grounds and weather
National park closures and what they take off the map
Which Thai marine parks close, and when?
The short answer
Which Thai marine parks close, and when?
Mu Ko Similan and Mu Ko Surin close from 16 May to 14 October each year. Mu Ko Lanta, which covers Koh Haa and Koh Rok, closes over roughly the same window. Maya Bay on Phi Phi Leh closes separately from 1 August to 30 September. Ao Phang Nga and Mu Ko Hong in Krabi stay open all year. Closures are ordered by the Department of National Parks for reef recovery and monsoon safety, and the dates can be extended, so they are confirmed each season rather than assumed.
What closes and when
| Park | Closed | What it takes off the itinerary |
|---|---|---|
| Mu Ko Similan | 16 May to 14 October | The nine Similan islands, the best water in Thailand |
| Mu Ko Surin | 16 May to 14 October | The largest shallow reef in Thai waters, the Moken village |
| Mu Ko Lanta | mid-May to mid-October | Koh Haa cave diving, Koh Rok |
| Maya Bay only | 1 August to 30 September | Maya Bay. The rest of Mu Ko Phi Phi stays open |
| Ao Phang Nga | no annual closure | |
| Mu Ko Hong, Krabi | no annual closure |
Why they exist
Two reasons that reinforce each other. The monsoon makes the exposed offshore parks genuinely dangerous for small craft, and the reef needs a season without visitors. Maya Bay is the clearest case: it was closed entirely from 2018 to 2022 after tourism destroyed most of the shallow coral, and it reopened under a capped-access regime with an annual two-month closure built in.
The closure is the fastest reliability test in this market. An operator offering a Similan charter in July is offering something that cannot legally happen, and that tells you what you need to know without asking a single further question.
Next
- National park fees, park by parkWhat are the national park fees for a yacht charter in Thailand, and who pays them?
- Northeast against southwest monsoon, and what each one closesWhen is the best time to charter a yacht in Phuket?
- Month by month in the Andaman SeaWhat is the weather like for sailing in Phuket in each month?
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.