[Jimbuna]

Originally Posted by Heibges

In real life, a fully underwater attack without the the aid of the periscope never took place in combat in WWII.

Maybe the Germans did it in training, and there is a story about a simulated attack in the last days of the war, but a real fully submerged attack never took place in WWII.

Additionally, when England sank the Argentine Cruise during the Falklands War, the captain of the British sub confirmed his firing data through the periscope.

Have a look here mate
http://uboat.net/boats/u864.htm