I know NOTHING about diving, other than the diver goes under the water surface. How deep can a man dive? How about a drone submarine? I would think that we are not the only ones with some pretty good submarine technology these days.
Basically, something that can place a charge on the pipe(s) (not the pips), get out of the area, and then detonate.
I know about as much as you.
Isn’t 78 feet the depth requiring decompression?