There is a worse cheat.
I can get the range of ships at 30,000 meters by clicking on suspected areas until it locks onto to something in the UZO. When it is locked click the watch officer for the range and he can tell you in a blinding rain. You need to be surfaced and with the radar detector fix you will likely be submerged and not have to use it but this is a cheat and not at all real.
I only stumbled on to this by accident and then tested it at long range. If you dive in front of a reported convoy and can hear them you can surface and use this if winning by methods impossible to real Kaleuns is desired.
Wulfmann