With no periscope raised, 20 meters below the surface, all stop, and silent running. I've been detected by DD's, DE's, and even Armed Trawlers in from 1000-1500 meters when they are running 12-18 knots even in the early years (1939 - 1940)??
I was thinking about creating a post on this subject when I noticed someone else was wondering the same thing. It's a head scratcher to me (is it a bug, or a compromise the GWX team had to make to get another area of ASW to work better?) I realize it is probably a variable that may affect other functions, but is there a variable in SH3 that allows the reducing of surface ship ASW detection the faster they go?
Their detection does appear to become more sensitive when they are cruising around at 4-7 knots trying to find me, so in gameplay their ability to detect feels right at slow speeds when they are actively searching for you. If I had a variable knob for this I would make them about 20% harder of hearing @12knots and about 40% harder of hearing @18 knots.
When I ponder this I can't help but think of the Admiral in The Hunt for Red October's line about Surface ships at medium to high speed and their detection capabilities - "At that speed they could run over my daughter's stereo and not hear it"..