Quick Tide Sailing: Auto GRIB

Routing that knows the tide: best departure time, fine-scale currents, automatic wind (AROME, ICON, ECMWF). Sail & motor. 3-day free trial.

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 at each step 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 positions and the closest to the finish. The winning tack is never thrown away.

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: Ifremer 250 m in Brittany and the Channel (Raz de Sein, Fromveur, Alderney Race), BSH on the Elbe, the Jade 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

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) shows an angle / wind-speed grid and fills it cell by cell as you sail: it waits for a settled regime, discards the minutes following a manoeuvre, flags doubtful cells. Everything is adjustable: settling delay, settled-regime duration, heading and wind tolerances, log or GPS, wind range and step. You fill the gaps by interpolation, correct by hand, merge several outings, export to .pol or .csv. That is your sail wardrobe, your propeller, your hull — 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/