When changing Gameplay Options, the one off of the Main Menu does the settings for the Single (Quick) Missions, War Patrols & MultiPlayer. When doing a Career, once you get into the Captain's Room while in-base (before leaving on patrol), you access the GamePlay options by clicking on the console radio box, to the left of the desk in the American side, or by clicking on the file cabinet by the Exit door if on the German side. Have you done those? What boat are you using that has the low observation scope?
