To illustrate the process, let’s say we’re planning a 4-day passage from La Rochelle (France) to Cowes (UK).

• Pan and zoom to your sailing area. Unless you’re doing an ocean crossing, pick a selection slightly larger than your route.
• Press the + button.
• Tap Download GRIB.
• If needed, adjust the selection using the four green corners.
• Press OK.

A Download GRIB window opens. The choices are filtered to your selected region.
Without the Premium option, you’re limited to the GFS model (the U.S. NOAA global atmospheric model).

• Choose the Type of data to download:
  • Atmospheric
  • Current
  • Sea State
• Choose the Coverage:
  • Global
  • Regional — for trips up to ~5 days, a regional model is usually best.
• If applicable, select the Region.
• Select the Model.
  See our FAQs for guidance on models.
  If unsure, choose the atmospheric global ECMWF IFS or GFS.
• If needed, check the Model description & coverage map.
• Select the Days and Timestep.
  If unsure, keep the defaults.
• Choose the Parameters (Wind, Pressure, etc.).
  If unsure, keep the defaults.

The estimated compressed GRIB size appears at the bottom. Keep it reasonable—if you see ~200 MB, you probably chose a model that’s too fine or too many parameters.

Below the model description, we show the latest model calculation time (the Run).
Run: 20251016 12Z +102 means: calculated on Oct 16, 2025; initialized at 12:00 UTC (12Z); contains 102 forecast hours from that run.
We also display the estimated time until the next run is available.

• Press Download GRIB.
• The GRIB file downloads from our fast, redundant servers.
• Once downloaded, it is:
  • displayed on the map. If you don’t see it, open Layers and enable Color map and Barbs.
  • added to the GRIB list in the left panel. Tap the ☰ at top-left to open the lists panel.