GeolocationTCP creates a simple TCP server which interfaces the Windows 8 Location API and serves NMEA sentences. Intended for use with OpenCPN.

The software is provided "as-is", no warranties. Use at our own risk!

How to use

  1. Download GeolocationTCP-r9.exe and start the program.
  2. Open OpenCPN, go to Options > Connections and create new Network connection with Adress and DataPort 15555.


  • Windows will try to locate your position using either of these sources: Cellular, Wifi, Satellite. Thus if you want to see what you get offshore, turn off your cellular and wifi connections.
  • The frequency of location updates might be quite irregular.
  • If your position in OpenCPN is off, try Settings > User Interface and set Show Lat/Long as to Degrees, Minutes, Seconds.


Open the project in Visual Studio and add references to Windows.Devices and Windows.Foundation. Then build.


GPL v2.0


  1. edrazy
  2. kalmangabriel