A typical NMEA 0183 sentence consists of:

Encoded AIS position report (requires decoding per ITU-R M.1371).

The National Marine Electronics Association (NMEA) developed the 0183 standard to allow multiple devices to share data over a simple serial interface. Unlike its successor NMEA 2000 (a CAN-based system), NMEA 0183 is (RS-232, RS-422, or TTL levels) with a talker-listener architecture: only one device (talker) can transmit on a line at a time, but multiple listeners can receive the same data stream.