SkunkTracker for macOS displays live, updating maps of ships and boats. It uses AIS data streams from your own dedicated AIS receivers or from network feeds. If you like, you can share your data with services like AIS Hub and Marine Traffic.

AIS (Automatic Identification System) transponders are carried by all large ships, all passenger vessels, and many recreational and small commercial boats.

Note: you need an AIS radio, or access to a public AIS feed, to use SkunkTracker. Your radio can be connected via USB, Bluetooth, WiFi, wired Ethernet, or a USB-serial converter. SkunkTracker can connect to installed marine transponders, to some multifunction displays/chartplotters, to a NMEA 2000 gateway like the Yacht Devices YDWG-02, and to low cost recreational grade receive-only AIS radios.

If your radio has a serial port, but doesn't have a network connection or USB connection, you'll need some sort of RS232 converter. You can use an WiFi-RS232 converter, such as the Global Cache WF2SL or the GridConnect RN370; a Bluetooth Classic converter like the IOGear GBC232A; or a serial-to-ethernet converter like the GridConnect ATC-1000.