Welcome aboard askir!
We here at Subsim are always like to harass, I mean help the new captains.
There is an issue with accuracy on the markings on the periscope for the fleetboats, I assume the u-boats have the same problem. Optical Targeting Correction explains the problem and fixes it, among other inconsistencies.
http://www.subsim.com/radioroom/down...o=file&id=3333
Good advice from Scurvy. Operation Monsoon introduces an Atlantic campaign. Very well done.
Now go outside and check for air leaks.