Hi @yuki, welcome to the forum
From what I understand the Water Linked GPS sends positioning data to the vehicle, which is fed into the vehicle’s EKF (Extended Kalman Filter), which merges it with the ROV’s IMU data and determines a position estimate from that combination of sensor values. The only data that gets sent from the vehicle to the GPS is the depth data, so the position values aren’t expected to be the same.
It may be present in the
GPS_RAW_INT message, which you can access from the MAVLink Inspector. If that does show the values you want then you can either plot those live, or pop out the window and look at the numbers. I don’t believe it’s possible to show the raw GPS values on the normal telemetry overlay.
If you’re interested in looking at values after a dive, you can use the Log Viewer to view the relevant
.tlog file(s) from your QGroundControl telemetry folder, where you can change the displayed trajectory source between
GPS_RAW_INT and see if there are major differences