[U-1966]

I'm reading a book called "The Golden Horseshoe", the Wartime Career of Otto Kretschmer. In one section of the book Kretschmer makes a list of 12 standing orders for the running of U-99 on Patrol. I implemented number 12 which reads:

"U-99 will dive for two hours just before dawn each day at sea. This will serve twofold purposes : first it will avoid the risk of running into ships and planes we have not seen during the night and which might see us first; and secondly it gives us a chance to use the hydrophones to sweep for unsighted ships. In addition, it gives the crew an opportunity to relax, clean up and have breakfast in peace."

I'm playing with the RUB Mod which makes single merchants scarce (as it should be), and single merchants do not appear as map contacts unless they are seen. But there I am cruising along after 7 days on patrol, I dive for two hours and the sound man picked up a nice C2! So using Kretschmer's orders helps to locate those lone ships.
So now I always dive for two hours right before dawn.

Another of Kretschmer's standing orders is also interesting for SHIII with all the controversy over deck gun usage:

"Lone Ships, not wearing neutral flags or carrying a red cross sign, and in every other way giving the appearance of behaving as a belligerent, should be sunk by gunfire if possible to conserve torpedoes for more difficult escorted targets. They may be torpedoed if gunfire is obviously impracticable."

Other of his standing orders mention giving aid to survivors, shadowing convoys by day and then attacking on the surface at night, and the importance of having good lookouts.