202.) In view of the fact that paint, especially on the wet submarine, is liable to reflect the light (shine), care must be taken not to show the enemy the moon-lit side. If the circumstances make this unavoidable, the tapering silhouette should be turned toward him as soon as possible.
203.) Take care that the submarine does not appear in the track of the moon on the water; i.e., in the line between the moon and the target.
204.) Favorable conditions of attack, enabling the submarine to remain unseen:
a) Attack the enemy when he can be seen against the light horizon, or against the moon, and move toward him from the direction of the dark horizon, or the dark portion of the sea. In this case, the submarine itself is invisible even at the shortest distances from the enemy.
Thanks Rubini for giving these procedures from U-boat Commander's Handbook more weight
Now it's easier to plan one's attack as if one needed to take consideration of the light from the moon as well.
To me this mod is not just eye candy!