Immersive techniques for the true subsimmer!

[Storm501]

I took a look at Uboat.net

Possibilities of underwater sound detecting in WW2:

Experienced underwater sound detector operator was able to determine is a detected ship a cargo ship or a warship (type of the warship), approximate speed or manoeuvre of the ship (approaching, digression, increasing or decreasing of speed and depth, if detected object was a submarine).

When detected (submerged) submarine stopped her moving, the operator was able to determine which mechanisms of the submarine still operated. To avoid own noises, a submarine could use underwater sound detector if her speed was up to 6 knots. If a submarine speed was 4 knots, the submarine's underwater sound detector average distance of detecting another object was:

- for a destroyer- 5 to 10 nautical miles, (9-18km)
- for a cargo ship- 3.5 to 7.5 nautical miles, (6-14km)
- for a convoy- up to 50 nautical miles. (90km)

If a submarine speed was 15 knots, the submarine's underwater sound detector possibility of detecting another object was rapidly decreased [although no submarines except XXI and XXIII were able to reach that speed during WWII]. In that case, average distance of detecting another object was up to few hundred metres.

Ok perhaps in game hydrophone is bit overpowered if it always hears Merchant at 25 km. On the other hand, these are average ranges at 4 kn speed, so at 0 kn or optimal conditions ranges could be up to 25 km.

So it is hard to tell a final conclusion. Seems that we are left with the first hand accounts of the people using the hydrophone. Also I have to believe that if using hydrophone at night would have granted a significant advantage, surely the U-boat crews would have seized it. Hundreds of crews had spent thousands of hours at sea, so I imagine they tried everything to increase tonnage sunk.