Meteorological Strategy for Passages

Weather is the single biggest variable in passage planning. A 'weather window' is a period when forecast conditions are suitable for your passage — considering wind strength and direction, sea state, visibility, and the capability of the vessel and crew. Identifying and using weather windows is a core skill for offshore sailing.

Before departure, obtain the most recent forecast from multiple sources: the shipping forecast (BBC Radio 4), inshore waters forecast, Met Office website or app, Navtex, and GMDSS SafetyNET broadcasts. Compare forecasts to build a picture of confidence. A forecast that several sources agree on is more reliable than one that differs between providers.

Once on passage, continue monitoring the weather. Listen to scheduled shipping forecasts, check Navtex, and observe the barometer. A falling barometer — especially a rapid fall of more than 3–4 mb in three hours — is a strong indication of approaching bad weather. A rising barometer generally indicates improving conditions, though a rapid rise can precede strong winds as a high-pressure system moves through quickly.

Knowing when to wait for a weather window rather than pressing on is a mark of an experienced skipper. There is no shame in waiting; the sea will always be there tomorrow. Equally, once committed to a passage, the skipper must be ready to respond to deteriorating conditions — reefing early, diverting to a bolt hole, or heaving-to if necessary. The key questions are: can we reach our destination safely, can we reach a bolt hole, and can the crew cope with the conditions?