OpenSail

Plan a passage against GFS, ECMWF, HRRR or AROME. Drag the timebar and the weather moves with it. Save it to your phone before you lose signal. Free routing to start.

OpenSail plans a sailing passage the way a good navigator would, then tells you why it chose that line.

ROUTING YOU CAN ARGUE WITH Set a departure, pick a comfort mode (Fastest, Balanced, Family, Comfort+), and OpenSail solves the passage against the forecast. Every route comes back with its reasons attached: peak wind and gusts, sea state, heel, hours under motor, and the places where the solver threw candidates out for depth or land. Solve all four modes at once and read a plain-language briefing on which one to sail and what the runner-up would have cost you. Planning and re-planning need a connection.

SCRUB THE WHOLE PASSAGE Wind particles, gusts, waves, ocean currents, isobars and squall risk, drawn on the map and moving with the forecast. Drag the timeline to 0300 on the second night and the boat walks to where it will be, while the numbers along the bottom read the wind, the sea and the boat speed it will meet at that hour.

WHEN A NEWER RUN LANDS The map says so, and offers to re-plan from where you are now. You choose the start: your GPS fix, the position you were meant to reach by now, or the original departure.

MODELS THAT DISAGREE, AND SAY SO GFS, ECMWF, HRRR, AROME, and Copernicus Marine currents and waves. OpenSail re-samples two of them along your own solved track and shows you where they part company. Run age and forecast horizon stay on screen. When a passage runs past the end of the forecast, OpenSail says so instead of inventing an arrival time.

DEPARTURE PLANNER Five departure windows over the coming days, each one solved in full. You get the hours, the peak wind and the seas for every window, then a briefing on which one won, which almost won, and what the losing hours would have cost.

ANCHOR CHECK Score an anchorage against forecast wind and swell before you commit to it, and set an email watch for when the forecast turns against you. This is not an anchor drag alarm. Watch emails need a connection.

SAVE THE WEATHER BEFORE YOU GO Phone signal runs out offshore. OpenSail is built for that: it keeps every route you plan on the phone, with its briefing. Before you leave, save GFS weather for the route corridor, or for a box you draw yourself. Check the download size, the fields and the coverage first, then leave OpenSail open until it finishes. Out of range, open the route and its weather with no signal at all, and the source, the run and its age are still on screen. Saved weather is for reading. Planning and re-planning still need a connection, and the bundled offline map is a coarse overview with no place names and no depths.

TAKE IT WITH YOU Routes out as GPX or KML for the plotter. Corridor GRIB files cut down to fit a satellite link.

FOR PLANNING, NOT FOR NAVIGATION OpenSail is a planning tool. Navigate with official charts and your own judgement. The app says so on every map.

WHAT IT COSTS A free account gets you real routing: one route a week, Fastest mode, up to 200 nautical miles, and the whole weather map. Voyager adds unlimited routes at any distance, all four comfort modes, every forecast model, the model disagreement layer, the departure planner, saved weather and route history. Passage adds offshore GRIB packs sized for a satellite link, and passage tracking. Pro adds API keys and the largest packs. Subscriptions renew automatically unless cancelled at least 24 hours before the end of the period.

Terms of Use: https://opensail.app/terms Privacy Policy: https://opensail.app/privacy

WHERE THE DATA COMES FROM NOAA (GFS, HRRR, NWS). ECMWF, CC BY 4.0. Meteo-France (AROME), Etalab 2.0. Copernicus Marine Service. Charts: NOAA ENC and OpenSeaMap. Basemap by OpenFreeMap and OpenStreetMap contributors.