Sources and times
Check the issue time, valid period and coverage of each product.
Marine weather for passage planning
Marine weather. A clear plan for your passage.
Find relevant official sources, compare available forecasts and prepare a brief you can revisit.
Public brief without an invitation; AI and separate specialist review are in closed testing.
Independent relaunch of this historic domain; not the former forecasting service. What changed
Example: how to read the result
An illustrative briefing structure, not a current forecast or a calculated route.
Model disagreement
If disagreement affects your limit or the timing of an exposed leg, reassess the departure window and an alternative.
Missing data
Missing local-current or warning data is a gap, not evidence of calm weather.
Next step. Add your legs, timing, yacht and crew details; open the official sources before deciding.
Find the right forecast area
Start with the waters you will cross. Each guide points to official forecast and warning providers, then explains what to check for a passage.
North Atlantic
Ocean bulletins and transatlantic planning.
Caribbean Sea
Marine forecasts and tropical systems.
Mediterranean Sea
International and national coastal sources.
US East Coast
Find the right NWS coastal or offshore zone.
Start with the essentials
How to read a marine forecast before a passage
A seven-step reading sequence: zone, warnings, issue time, wind, sea state, observations and a decision checkpoint.
Wind and waves: why one number is not enough
Understand mean wind and gusts, significant wave height, period, swell and the exposed parts of a route.
What to do when marine forecasts disagree
Compare the same place and forecast hour, identify decision-changing differences and plan for uncertainty.
AI and expert forecasts: closed testing
Personalised forecasts for individual passages are in closed testing. The programme brings together route context, traceable weather data and AI-assisted analysis, with human review identified separately. Public guides, source directories and the passage brief remain available without joining the closed test.
A useful briefing starts with context
There is no universal “safe wind speed”. The same forecast can mean different things for different vessels, crews, routes and escape options.
- Check official warnings and the latest local marine forecast.
- Compare the forecast with recent observations and its update time.
- Consider gusts, waves, visibility and the whole route—not one point.
- Leave a margin for uncertainty and a plan to postpone or divert.
Prepare a passage in three steps
Choose the actual waters and departure base. Read the relevant weather and planning guidance. Bring current sources, leg timings and personal limits into your passage brief. This sequence keeps a useful model comparison connected to the real trip rather than treating a coloured forecast map as the whole decision.