Side-scanning sonar would be amazing!
Especially to view in real time (and be able to record) in two inset windows in QGC:- First window: the live reading,- Second window: the time (2.5D) profile of surveyed areas/objects.
It is possible to add third-party sonars and use their software with the BlueROV2 by simply using the spare wires in the tether. Direct integration of a sonar into QGC is possible, and something we hope to do down the road. This is difficult to do for everyone at the moment, because it will depend on the communication protocol of the sonar. We will have to wait until we have a sonar that we can officially back and support.