I am researching type II U-boats and I am in the book "U-boats, The Illistrated History Of The Raiders Of The Deep" by David Miller.
For anyone who has this book on page 20 he claims that the Type IIA had a single periscope yet the picture at the bottom of the page of U-1 shows what looks like two raised periscopes.

(The aft scope is obviously an attack scope but the forward one is hard to tell...could it be a flagstaff?)
Can anyone confirm (and what source) that Type IIA's and B's had only 1 periscope and it wasnt until the Type IIC's that a second scope was added?:hmm: