The router on the phone needs weather in a compact form, plus the land and depths along the way so it does not route you over a shoal. When you download the right kind of forecast, the app prepares both for you.
Download a routing pack
A download can be routed on when its layers are only Wind, Waves and Currents. Those come as compact routing packs, about a third of the size of the same forecast as GRIB.
- Open Get. On the chart, tap Wx, then Get.
- Where. Choose Along route for the passage, or size the box to cover the whole course and some room either side.
- Layers. Keep to Wind, and Waves and Currents if you want them in the route. Leave Gusts and Pressure off.
- Hours ahead. Enough for the passage and a margin.
- Download.
When the last part has arrived and checked out, the forecast becomes routable on its own. The app then fetches the land and depth data for the same corridor, once. It shows in the held forecasts as Land & depth.
From a project
When a project has a course and its readiness says weather is missing, tap Download weather for and the route's name. It downloads GFS wind along the route as a routing pack.
Check it is ready
On the Route tab, Offline readiness says what the router will use:
- Weather — Ready through a date and time: the forecast covers the passage that far.
- Weather only downloaded through a date: the download stopped short, so the route will too.
- Routing pack missing, with the reason.
The project's readiness and the Go sailing sheet check the same things before you leave.
Limits
These cannot be routed on: imported GRIB files, any download with gusts or pressure, ensemble forecasts, and a download still arriving. They still draw on the chart.