Maris and Dura Mater made individual calls to each other through their AIS MMSI numbers today. And it worked. Of course, the volume on my radio was turned down and I had to turn it up in order to hear Brian. That old joke. Now I know my AIS works. Brian Boschma says large container ships tend to not respond to "Container ship at [lat/long]", but they DO respond when their name is used: "Dura Mater to the Container ship 'Maersk Dunga Din'".