Passage by DeepRegatta

Explainable weather planning for offshore sailing passages.

Passage audits the weather along your intended route before you commit to a departure. Instead of a single deterministic forecast, it shows you the conditions each leg is likely to meet, how much the forecast models disagree, and which assumptions the verdict depends on — so the go/no-go call stays yours, made with open eyes.

How a passage audit works

  1. Enter or select a departure point and destination to sketch your route.
  2. Choose a departure time, or scan a window of candidate departures to compare them.
  3. Inspect wind, tide, and current along each leg, the ensemble spread across forecast models, and alternative timings for the same route.
  4. Review the briefing's uncertainty and assumptions: active warnings, where models diverge, and how recent forecasts have shifted.
  5. Save the briefing as a snapshot to keep the decision context — the forecast evidence as it stood when you made the call.

Try it with an example route

A ready-made briefing for a Cherbourg to Plymouth crossing is built in. Open "See an example briefing" on the planner to explore the full audit — route timeline, tidal gates, warnings, and forecast evidence — without entering any personal data or creating an account.

What Passage is — and is not

Passage is a planning aid. It does not replace a current forecast, official marine warnings, or the skipper's judgment. Official marine forecasts remain the authority of record; always check them before departure, and treat every Passage verdict as evidence for your decision, not the decision itself.