Lots of interesting stuff there, thanks!
I was looking at the u-boat commanders handbook in there and came to this
"The following rule of thumb serves to determine, in good time, the distance of the submarine
When about launch the attack, (torpedo) abreast of the enemy.
In position 5°, the lateral distance from the enemy = 1/10, in position 10° = 1/5, in position
15° = 1/4, in position 20° = 1/3, in position 30° = 1/2 of the momentary distance."
Does anyone have any idea what this means??