Anyway, when I got home, the report was in from my Jutland expert. There was only 10 submarines lined up before British ports before Jutland. Battle plans had changed and they were at the end of their reserves when the British feet came out. The submarines of the time were nothing like their WWII counterparts. They were not very maneuverable and probably couldn't have sunk a heavy warship close to port. Destroyers, yes, but not dreadnaughts. If the submarines could get into firing position. Still, the loss of a few destroyers would not alter the balance of power. Still, it is fairly certain that several U - boats sank the Black Prince.

A possible scenario: Suppose Marguerite fell for a British naval officer who was a German "sleeper". He finds out Marge works for Room - 40 just before the Fleet leaves port for the naval engagement off Jutland. He could send a coded message at sea warning the Germans about her. Marguerite's effectiveness as a spy would end then and her secret intercept stations would be endangered. His main job, however, is to betray the British Grand Fleet at some critical juncture.He is aboard the Black Prince and the Prince is a part of an important heavy cruiser formation. Something he says to Marge puts her on to him. When he makes a "mistake" during Jutland, sending his formation in the wrong direction and out of the battle Marguerite knows what she must do. She uses the submarine codes and the Black Prince is blown up. Following the blast, the formation returns to the battle and does significant damage to the Germans. Her lover is badly injured in the explosion, picked up by the Germans, but unable to betray Marguerite for months. Her cover isn't broken following Jutland. When the war ends, he's back on his feet. Is he the marksman? But someone else might have escaped, or, perhaps it was the family of someone aboard the Prince, someone that figured out she had sent the codes when the rest of the British Navy and Room - 40 didn't know what she's done.So, Marguerite might have influenced the outcome of Jutland after all, at least segments of it.
Steve Faust