yes but
a) submarine sonar is very powerful - it can kill marine life. Pricey even if not restricted.
b) submarines don't try to shoot the beam down a 1.5" pipe.
the resistance idea is on a sound theoretical basis but has lots of practical complications: corrosion, differing conductivity of the water over time and mechanically maintaining the distance between the wires in a 1.5" pipe while avoiding contact with the metal shaft. If one was willing to attempt that, a better solution would be measuring capacitance between two sealed wires. However keeping the wires at a uniform distance over a 600' height is just not practical.
Personally, I think measuring the head pressure while pumping is the best solution. it does mean that you can't monitor on a minute by minute basis but don't think it's all that valuable. I think you can derive all the info you want from that data. To get minute-by-minute data with the pump off, the bubbler is the best solution.