The chart works anywhere from the moment the app is installed. A coastline of the whole world is built in. For depths, buoys, lights and the rest of the detail, download the official NOAA charts (ENC) for where you sail. Once downloaded, they are drawn on the phone with no connection.
What is already on the phone
- A world coastline. Land and water everywhere, at about 40 m detail, good enough to show narrow bays and channels at a few miles' scale. Further out, a lower-detail world map takes over.
- San Diego. A more detailed coastline, and OpenSeaMap's crowd-sourced seamarks.
None of this needs a download or a connection.
Download NOAA charts
- Open the library. Tap Chart on the toolbar, then Chart library. The screen is called Charts.
- Choose what to download. Under Download, tap Charts for the visible area for what is on the chart now, or Charts for your route when one is set. Under Regions, tap Download beside a whole region; each shows how many charts it holds and its size.
- Check the size. A sheet shows how many Charts, how many are Already on this device, and the Download size. Tap Download.
- Wait, or go. Downloads continue in the background and resume after an interruption. Each download is listed under Downloaded with its progress and a Cancel button.
You can also reach the library from a project: when its readiness says charts are missing for the route, tap Get charts for the route.
Keep them up to date
NOAA issues updates to its charts. At the top of Charts, On this device shows the space they take, how many are installed, and when the catalogue was last checked.
- Tap Check for updates on a connection.
- Updates available lists how many charts have updates and their size. Tap Update all, or Update on one download.
- Remove on a download deletes its charts. It needs a two-second hold.
Check coverage
Tap Coverage for the charts installed in each scale band, their editions and updates, and what the visible area or your route is missing. Turn on Show on chart to outline the installed charts on the chart itself.
Where charts of different scales overlap, the chart draws the most detailed one that suits the zoom and never doubles them up.
Limits
Official charts cover US waters, from NOAA. Elsewhere you have the world coastline, with no depths or marks; the crowd-sourced marks are built in for San Diego only. The chart is rendered on this phone and is not certified for navigation.