This way might be a solution for my old idea of using AIS sentences for ROV positioning on bridge/helm position.
Sending position as AIS via UDP or serial to a ROV dedicated plotter or PC based system.

-Gives automatic distance and bearing to ROV
-Displays ROV on Nautical charts
-Easy working with Gpx waypoints and tracks
-Easier manouvering of ship related to ROV

Bo Koppel