How do they communicate with it underwater? Do they have some sort of RF-to-acoustic repeater?
Dittos, my biggest question. You can see how they do pitch control at the very beginning, and it benefits from electric motors flat torque curve. So how are they communicating? And does it know it’s in water or is the operator telling it? When the operator can no longer see it under water he has to use a screen to guide it so it’s back to the communication question.
With the short distance, and depending on the freq, probably the RF works just fine.