This is a feature that I’m still trying to understand. I believe it is an AIS message, and possibly a distress message, but have not been able to figure out what it means. I get the same result whether I push Show or Close, in that the alarm dialog closes and no cursor is selected.
I have a GARMIN AIS™ 300 Blackbox Receiver connected to my NMEA 2k network, and assume that it generated the message on the local network and the B&G is just displaying it. Because I don’t have an AIS transmitter, I don’t believe it’s a directed message to me. I’m not broadcasting any ID, and my radio isn’t hooked to the GPS, so isn’t configured to be able to broadcast distress signals. (One more item in my to-do-list)
The only annoyance I have with this type of message has been when I left the instruments running while i was away from the boat and returned to find the alarm beeping and a similar message displayed. I don’t like that the beeping may have been annoying my neighbors for days.