Plugin radar_pi

radar_pi is a plugin for OpenCPN that allows full integration of certain radar scanners.

_This manual is updated to include radar_pi version 5.2.2

The following radar scanners are supported:

  • Garmin HD

  • Garmin xHD

  • Navico Broadband Radar BR24

  • Navico Broadband Radar 3G

  • Navico Broadband Radar 4G

  • Navico HALO (20, 20+, 24, 4, 6, 8)

  • Raymarine (older) radars

  • A simple emulator

  • (Not fully verified support for Garmin GMR18 is reported)

The plugin can be operated as the only control station for your radar scanner, as it allows access to all setup operations such as antenna direction correction and antenna height, as well as cooperate in a multi-station setup – whether multiple OpenCPN installations or one or more MFDs/plotters. In fact using a mixed setup is what 2 out of 3 developers use, and recommend (our laptops and tablets don’t work nearly as well outside as the dedicated plotters.)

It supports up to four radars, with the dual-range Navico radars counting as two radars, as long as all radars are of a different type. So you can connect both a 4G and a HALO radar and enjoy dual range on both physical radars, combining to four different scans simultaneously on your computer screen.

The plugin has class leading ARPA and MARPA support, supporting 50 ARPA and MARPA targets independent of used scanner type. For Navico Halo types also the doppler function is supported. Target trails support comparable to commercial level radars as well as guard zone support. It supports two guard zones per radar as well as two Electronic Bearing Lines (EBL) and Variable Range Markers (VRM) per radar.

The following pages document the plugin for end users:

Further development

For more insight in what it takes to add a new radar type, such as Furuno or more Raymarine, see Adding new radar types.


This plugin was initially developed as a BR24 plugin by Dave Cowell who took Dave Register’s Garmin plugin and modified it to work with the BR24. Over the years code was contributed by @Hakansv, @douwefokkema, @seandepagnier, @nohal, @chucksk, @ab2nkovs and @canboat. After v3.0 was released the code was changed again to support multiple radar types, and adding Garmin support back in with the help of @trudK45 and @bdbcat.