As has been reported many times on this forum, there seems to be a discrepancy with the A.I of Japanese with regard to A.S.W. After much Investigation, infiltration and other disreputable tactics I have discovered that the japanese had a 'S.A.L.D.' (Sub Aquatic Laser Designator).
This would account for the fact that although My sub was at 90 meters and engines off I was detectcted almost beyond visual range (8km) whereupon 3 destroyers made a beeline for my position and dropped an ashcan right into my conning tower. Consequently I am making this report posthumously.
As there were limited numbers of the aforementioned device it explains why some are 'ace' and the others are rubbish.
As this device was developed and manufactured in Hiroshima, no trace of the device was ever discovered.
NB Is it possible that the 'devs' had foreknowlege of this and hardcoded it into the sim?