your best bet is to plot a 6 hours interval course inside the AO, and to dive to 40 meters, zero engines, put on a
Thomson HED415N and slowly move the middle mouse button. Repeat every 6 hours stationary or 3 hours on the move.. At least I do so..
Oh, do remember:
The sound guy can find more contacts with the GHG than with KDB, AND you dont have to submerge as above (except if using historical uboat specs mod, where you must be at 12 meters depth for them to be effective.. ).
Unlike the GHG, the KDB is worse since you have to plunge to listen( decks awash doesnt cut it
)
hope this helps.. Oh, when the war is over, you can file a courtmartial against Benno Scheu for being a spoiled USELESS mumma's boy..