[letterboy1]

If you try it, make sure you change the one in this directory:
C:\Documents and Settings\Steve\My Documents\SH4\data\cfg

Not the one here:
C:\Program Files\Ubisoft\Silent Hunter Wolves of the Pacific\Data\Cfg

When you play, SH4 uses the first one. The main.cfg in the SH4 directory is only a reference file that the game uses to reset defaults.

Change it from:
DynamicShadows=No
to:
DynamicShadows=Yes

The difference is supposed to be noticable when you have enough wind so that the waves begin to roll and you can see a difference of lighting between the side of the wave facing the sun and the dark side.