This failure caused an international uproar led by the United States, which resulted in a curtailment of German U-boat warfare for two years.

In five years of training he only spent one week studying U-boat warfare.

Towards the end of 1943, Admiral Dönitz demanded that the entire output of Ju 290s be made available for U-boat warfare.

With unrestricted U-boat warfare during World War I shipment was delayed until the war ended.

They waited to gauge the effect of unrestricted U-boat warfare, which had commenced on 1 February 1917 in the hope of starving the British into submission.

The resumption of unrestricted U-boat warfare early in 1917 had not surprised him; it fitted his recollections of his earliest history lessons.

Unrestricted U-boat warfare also, however, posed enormous risks.

Germany responded by ordering U-boat warfare against Allied merchant and war ships (Battle of the Atlantic).

His performance literally changed the German vision of U-boat warfare.

Lohs had also some very good ideas on U-boat warfare and new tactics and on April 24, 1918 he received the Pour le Mérite.