Well last night I found that just as in SH3, my sound guy can't hear things that I do. So, on this first offical patrol, off the eastern coast of Britain I have been the one to actually hear our first contact.
With motors off, I could near a verrry faint sound of a merchant's screws.
At about 2:10am game time, I finally got tired and went to bed but had managed to get close enough to where gosh he surely can hear this now, cause we are nearly in visual range cause with the periscope up, my watch officer has reported "smoke on the horizon" and give a bearing.
I even gave Denno the level 1 "total revealing" ability and still he has not reported a thing.
Yet still when I man the hydrophone I can clearly hear it.
This even after I had Olaf feed everyone a special meal.
Well when I come back to this save the fog will likely be gone and we'll have this ship clearly spotted and our first kill will be in the bag.

But no thanks to Benno..............