Quick Tide Sailing: Auto GRIB

Quick Tide Sailing plans and runs your passages, under sail or under power: routing, multi-model GRIB, current and tide, ORC polars, marine charts. Free to start.

THE ROUTING, AND WHY IT IS FASTER Draw your route, pick a departure time, run the calculation. The isochrone algorithm looks for the fastest track from your polar, the wind, the swell, the current, the day/night cycle and your motoring rules, while clearing the coast.

The calculation advances by successive fronts, discarding the positions with no future. A classic router keeps, per sector, only the one furthest from the start. Upwind that criterion turns against you: the tack that gains towards the mark is not the one that goes furthest away — it gets discarded, and the route commits to a long losing board. Here each front keeps both, the most advanced and the closest to the finish.

Measured on Groix-Ouessant, same GRIB and same polar, 100 % sailing: 16 h 57 for 100 miles, against 20 h 40 for 152 miles on a well-established consumer router. Three hours forty less, 18 %. The gap comes from the algorithm, not from the engine.

AND FOR MOTORBOATS Raise the "Motor below" setting above any speed under sail and enter your motoring speed: the routing becomes a power calculation, current, tide, swell and coastline included. Against a 5-knot tidal race, an 8-knot motor cruiser stakes its day on the time of passage.

THE CURRENT IS PART OF THE CALCULATION Current is not a decorative overlay: it enters the routing. Useful wind is taken in the water frame, and speed over ground follows. • From the Baltic to the Mediterranean, 412 current areas of at least 1 knot, surveyed over a full spring cycle • Fine mesh where current makes the day: our own 100 m model on the English coast, Ifremer 250 m in Brittany and the Channel, BSH on the Elbe and the Belts, Copernicus Marine elsewhere • Tide computed on board: heights, high and low waters, at any date, with no network • Best departure time: a sweep compares the departures in your window and keeps the one that passes the races at the right moment

WEATHER AND MODELS • ECMWF and GFS offshore, up to 10 and 16 days • AROME 1.3 km and ARPEGE 0.1° (Meteo-France), ICON-EU 7 km and ICON-D2 2.2 km (DWD) • The finest model for the area is offered; the GRIB follows the extent of your route

THE SOLENT, MODELLED FOR ITSELF General-purpose current sources work on a 1.5 km grid — three cells across a channel three miles wide. We built our own: a hydrodynamic model of the Solent, the Isle of Wight, Hurst and the Needles on a 100 m mesh. Developed with AI assistance, from open data, checked against published tide gauge records. Harmonic tide: currents for any date, months ahead.

YOUR POLAR, MEASURED UNDER WAY Start from the monohull and multihull library, from the ORC database — thousands of certified boats — or from your own CSV and .pol files.

Then build your own at sea. The capture workshop (experimental) fills an angle / wind-speed grid cell by cell as you sail: it waits for a settled regime, discards the minutes after a manoeuvre, flags doubtful cells. Interpolate the gaps, correct by hand, merge outings, export to .pol or .csv. That is your boat, not the sister-ship's.

The display then puts your speed against the target: 96 % upwind, you are still looking; 103 %, you are holding the right trim.

ON BOARD • Instrument display (NMEA 0183, Signal K) • Alarms: anchor drag, shallow water, strong wind, cross-track error, battery • AIS, tracks, passage table, GPX export • OpenStreetMap and OpenSeaMap charts: marks, soundings, seagrass • Offline: cached charts, GRIB kept on board, tide computed without network • Comparator: overlay several routings and replay them

GFS wind routing is free, without limit. Auto-renewing subscription: it renews unless cancelled at least 24 hours before the end of the period, and can be managed in your App Store account settings. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/