Jungman,
I found a somewhat authoritative information on UK sonars at the
HMCS Haida site and at an affiliated
research paper. HMCS
Haida was a Tribal-class destroyer commissioned in 1943.
Based on what I found here, a minimum active sonar range of 200m (or even 150m) seems awfully generous - you would have to be pretty deep (>400m) to have a minimum detection distance of 150m once the Allies start deploying "Q" class sonars, with the ability to ping 70 degrees from horizontal, starting in 1942; starting in 1943, the minimum detection distance would be "0" once "Sword" (type 147B) sonars were deployed, since they apparently could look
behind and beneath the escort.
Do you know if the minimum detection distance a fixed value, or does it change with sonar type and range as in real life?
Pablo