Abstract: An automatic real time navigation communicator that communicates between vehicle mounted speed and heading sensors and the vehicle mounted satellite navigator. The communicator automatically and at predetermined intervals updates the satellite navigator with the most current vehicle speed and heading parameters during those periods when the satellite navigator is not in communication with a satellite. The communicator is particularly useful on ships for processing heading sensor information presented in a 3-bit binary format and presenting both heading and speed information to the satellite navigator in parallel BCD format.