The NMEA 0183 has two different communication (baud) rates for-4800 baud and the faster 38400 baud (also known as NMEA 0183-HS). You have to match the baud rate of both devices for communication to occur. AIS will always use the faster rate. Once the speeds correlated on our test boat, the radio presented targets on its one-inch display. Sitting at the dock it was apparent that info below decks was useless.