From Epics of History: More Prisoners of Eternity.

In Germany a submarine was called an U-boat, or “Unterseeboot”. At the outbreak of World War One, Germany had 33 of them. With the possibility of rich prizes off the British and Irish coasts and in the Channel, in early 1916 an entire flotilla of 24 U-boats was launched in the North Sea. One of them was the U-65, and from the very beginning there was talk about “jinxes” and “hoodoos”.

The deadly attacks at sea. The peril of the Allies. The secret mission of the German regime.