AIVDM & AIVDO NMEA sentence decoder

AIS receivers and transponders report received messages over the NMEA protocol in AIVDM sentences. They look something like this:

!AIVDM,1,1,,A,13u?etPv2;0n:dDPwUM1U1Cb069D,0*24

AIVDM messages are AIS reports from other vessels, and AIVDO messages carry your own ship’s data.

Below is a very simple decoder for NMEA AIVDM sentences. Currently it only decodes message types 1, 2, 3, 4 and 24 – i.e. position reports for class A shipborne equipment, base station reports and static data reports. Some less interesting data is left out from the result, but the good stuff is there! Where applicable, you will also get a link to Google Maps where you can check the target’s position.