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opencpn

Marine chart plotter -- your position and AIS ships on nautical charts

What it does

A chart plotter and navigation program for boats: it draws official nautical charts (vector S-57 ENCs and raster BSB/KAP charts, among others), shows your own position, heading and track from a GPS, plans routes with waypoints, and shows AIS ship targets with their names, courses and closest-approach warnings. The packaged build includes a chart downloader, a dashboard of instruments, a GRIB weather-file viewer and the world magnetic model.

Why you would want it

It is the one program that makes the ships category more than a decoder: rtl-ais and ais-catcher turn an SDR into an AIS receiver that outputs NMEA, and OpenCPN is what draws those ships on a chart around you. For a station on or near the water -- a harbour event, a maritime-mobile operator, an EMCOMM deployment on the coast -- it is the offline alternative to web AIS maps and to phone apps. It is the open-source alternative to commercial PC chart plotters.

Before it will work

Charts: none come with it beyond the world basemap. The bundled chart downloader fetches free official charts (for US waters, NOAA's ENCs) while online; after that they are files on the disk. A position source: OpenCPN's Connections settings take NMEA from a serial port or from the network, and gpsd as a network source. On this station that is gpsd itself, or the gps-tether launcher from the navigation profile, which serves gpsd's position as NMEA on 127.0.0.1 port 10110 (TCP). Ships: an AIS decoder (rtl-ais, ais-catcher) sending NMEA to a network port OpenCPN is told to listen on. None of these connections has been set up and tried by this project.

How it installs

  • apt: opencpn

Known problems

Unmeasured here: OpenCPN has not been opened on any target, so its OpenGL display on the field laptop's Intel Iris Xe, its gpsd and gps-tether connections and an AIS feed from rtl-ais or ais-catcher are all untried; the paths above are what the programs document, not what has been run. The archives differ by three feature releases (5.8.4 to 5.14.1, measured 2026-09-30), so dialog names move between targets. OpenCPN's plugin manager can fetch further plugins from upstream's online catalog: those are binaries from outside apt, not reviewed or tracked by Hammunition, and hammunition uninstall does not remove them.

Keeping it current

  • probe: apt policy
  • strategy: apt_upgrade

Where to get help with the software itself

The OpenCPN project. The user manual and the community forum are linked from opencpn.org; bugs go to GitHub issues at https://github.com/OpenCPN/OpenCPN.

Source: catalog/packages/opencpn.yaml