This is a game engine thingy, but settings are adjustable in a the '..\Data\cfg\contacts.cfg'.
Changing these settings does not cure your crew of blindness - and you know what causes seamen to be blind
[ContactSettings]
; Contact settings
Display Range To Opportunity Radio Contacts=300 ;[>0] kilometers
Display Range To Important Radio Contacts=1500 ;[>0] kilometers
Decay Time For Important Radio Contacts=172800 ;[>0] seconds
Decay Time For Opportunity Radio Contacts=32400 ;[>0] seconds
Decay Time For Imprecise Sensor Contacts=600 ;[>0] seconds
Decay Time For Precise Sensor Contacts=60 ;[>0] seconds
Single Contact Min Size=1 ;[>0] minimum numbers of units in this type of group
Small Contact Min Size=2 ;[>0] minimum numbers of units in this type of group
Medium Contact Min Size=5 ;[>0] minimum numbers of units in this type of group
Large Contact Min Size=13 ;[>0] minimum numbers of units in this type of group
[ContactRange]
;under the (right) value a contact is considered as:
Short=1000 ;[m]
Medium=3000 ;[m]
Long=20000 ;[m]
[ContactSpeeds]
;less than each value means (in this order): stationary, slow, medium and fast speed ; over the last value means very fast speed
Merchant=2,5,10,20 ;[kts]
Warship=2,5,10,20 ;[kts] including uboats
Air=2,5,10,20 ;[kts]
Convoy=2,5,10,20 ;[kts]
As you can see, it's self explanatory..
