This is a pre-passage source and decision desk, not a current forecast or clearance to depart. The map is centred approximately on the area, not on your route or a forecast-zone boundary.
National forecast responsibility changes quickly across these coasts and straits. Check the exact marine zone, tropical-system alerts where applicable, visibility and the latest local port or traffic notices.
1. Primary sources
Open current bulletins and warnings for every sea area on the route. These links are starting points, not a promise that each covers the whole location; if unsure, identify the issuer through WMO–IMO.
2. Route and local effects
Do not reuse an Andaman forecast on the other side of the peninsula.
A Gulf of Thailand cruise crosses coastal sectors and may move from a sheltered bay to open gulf water.
Use TMD shipping forecast for the correct gulf sector, not an inland city forecast; inspect thunderstorm warnings and the sea state on the exposed leg.
How to use this source set
Start with the warning, then the marine text for the exact named area. If the route crosses a zone boundary, obtain both bulletins. Note issue and valid times, wind units and the meaning of wave height. Where a link opens an agency portal, navigate to its current marine product; a homepage is not itself a forecast.
Compare with an exposed station or buoy if available. Check its position and observation time: a sheltered station does not overturn a warning for an open channel. If a bulletin is missing or stale, identify the issuing service via WMO–IMO and defer the decision until current information is available.
Before-passage check
- Mark departure, exposed legs, arrival and feasible diversions; find the responsible named marine areas for each.
- Check warnings, issue and valid times; assess conditions when you expect to reach each leg, not only at departure.
- Compare wind and gusts, waves and swell, visibility, thunderstorms and local effects; do not infer a strait from a sheltered harbour.
- Compare recent observations where available, noting their time and exposure; a mismatch calls for another check.
- Set the next bulletin check, a reassessment trigger, an alternative and a backup communication channel.
Model map — optional
Windy is a third-party model display, not the issuer of official warnings. Choose a layer and check its valid hour and model run. Nothing loads until you click.
Without JavaScript, open the map separately.
If connectivity fails
Before departure, save the current official text bulletin and warning with issue time. Arrange another way to receive updates, such as an appropriate coastal broadcast, NAVTEX or satellite channel. A saved map cannot replace new warnings.
How to choose weather tools · All sailing areas
Scope: Source list assembled 25 September 2026; check its freshness and coverage before use. This public area guide is not a current personalised forecast, navigational notice service or safety verdict. Personalised forecasts with AI and experts are in closed testing; public booking is not open. The skipper makes the decision.
Upper and lower gulf are not interchangeable
TMD's shipping forecast distinguishes upper and lower Gulf of Thailand information. A Pattaya-side trip, a Samui-area circuit and a cross-gulf passage should not inherit one city forecast. Preserve the named gulf section, warning and valid interval for each actual leg. A longer eastward or international continuation also needs the applicable neighbouring service; the Thai coastal product is not a forecast for every shore of the gulf.
- Thai Meteorological Department shipping forecast — Gulf and Andaman/Malacca sections; current warning must be read directly Direct product verification is limited; obtain the current issue from the issuer.
- WMO–IMO marine warnings and issuer directory — METAREA service selection; website can have delayed or interrupted products
Read the sea in showers separately
Do not reduce the shipping text to average wind and one wave number if it gives stronger sea or gust conditions in thundershowers. That distinction matters at an island gap or exposed approach even on a short charter leg. Use current warning and observation times rather than a saved seasonal description. An airport wind or sheltered beach report cannot independently establish offshore waves or a squall's arrival.
Build a two-leg itinerary before comparing starts
For an island visit and return, calculate the gap and final arrival ETAs in both directions. If a delay makes the return depend on an expired issue or unverified destination shelter, refresh or shorten the plan. Preserve the original warning wording alongside a checked translation. This desk does not define one universal gulf wind limit or replace current port, reef and navigation instructions.
Editorial review of this material: 27 September 2026. This date concerns the page content; check current forecast issue times and validity at the original sources.