Other than the map, how does GPS display?
The GPS coordinates in the next version of QGC will be available for display with the other telemetry by the compass/attitude indicator.
How do I know if GPS is working?
You will see your position on the map, the correct coordinates in the telemetry display, and the main LED on the pixhawk will turn green instead of blue.
Do you have a GPS antenna connected to the Pixhawk? Normal GPS antennas will not work underwater. You need another type of positioning system like the Underwater GPS Developer Kit in our store.
Best - Jacob