I don't know if I have navbus connection or to use nmea. Both VHF and gps are navman. Will try both and see.
Always something going wrong, all part of boating.
Set off on round the island of Anglesey last year, dropped a stick in the fuel tank when filling, then changed the setting on the gps so that we had no charts for the swellies when going through at below half tide. Screen went White. LOL, my old man was convinced I'd done it to wind him up.