Hi Paul,
Always glad to see another person interested in the U-boats. I'm still surprised that I converted Pat, since her favorite Titanic person is
Lightoller, whose only use for U-boats was to sink 'em and revile 'em.
Silent Otto is a fascinating fellow indeed, even following his capture...the Battle of Bowmanville in Korvettenkapitän von Müllenheim's memoirs is an good read, and finding out Kretschmer's role in it is equally interesting!
Interestingly, von Arnauld's younger brother Friedrich became a naval pilot and actually flew the first launch of a plane from a submarine--off the deck of Walter Forstmann's U-12, the man who, between U-12 and U-39, came up right behind von Arnauld in tonnage before taking a shore command.
I'm at work on (slowly) translating "Werwolf der Meere", and after that will try Moraht's 1917 book about the sinking of the battleship Danton, which, until Prien's sinking of Royal Oak, was the largest warship sunk by torpedo. If you're interested, once I finish, I'd be happy to e-mail you the file.
Moraht had an interesting life in submarines before his capture in June of 1918, and equally interesting following the war. He took a PhD in economics, was elected to the Reichstag in 1932, rejoined the Navy in the '30's and served as a port captain in Norway during WWII. It surprises me that he somehow survived three years ('45-'48) in a Soviet PoW camp, considering he was sixty years old in May of '45.
Thomas is an interesting read, though more anecdotal than military--but where else will you read direct accounts of crazy stuff like von Arnauld's monkey? It definitely gives you a sense for the personalities of the men involved, though.
Less than ten years after the US entered the war in rage over U-boat tactics, an American journalist's book of interviews with these same commanders was a bestseller. Go figure!