[_Seth_]

Here the IIA has only one scope;
http://www.u-boot-archiv.de/typen/typ_iia.html

Here is a summary of the type II boats:
http://www.uboataces.com/uboat-type-ii.shtml

Here is a quote:
Models A and B possessed a single periscope, while C and D incorporated a second attack periscope housed within the tiny conning tower.

From:
http://www.uboatwar.net/II.htm

Hope this was helping..