Cold Waters NavigationSonarRange

Does anybody know what the parameter NavigationSonarRange=4000 is in the main config file in the default directory? It seems obvious but I've set it to crazy large values and it doesn't seem to change anything in the game play.

Thanks in advance

[steel shark]

Basically its your Ice & mine sonar detection range

Mine and Ice Detection Avoidance system or midas for short

for example on a Los Angeles Class fast attack subs ice detection is

AN/BQS-15 close range active sonar for ice

i think you can also MARK ICE positions visually with your periscope as well