No, NMEA 0183 is not a CAN bus. It is a simple serial communication protocol that is commonly used in marine electronics to transmit data between various devices such as GPS, radar, depth sounder, and chartplotters. In contrast, CAN bus is a more advanced communication protocol used in various industries for real-time data transfer and control, such as in automotive and industrial applications. NMEA 2000, on the other hand, is based on the CAN bus protocol and is specifically designed for use in marine environments.