U Boat attacks accounted for million of tons of merchant vessels and Royal Navy units during the campaign.
Losses were so high during 1915-16 the British Government believed Britain could be starved into submission.

Also shown is an presumably staged engagement with a Royal Navy Q Ship, a vessel designed to appear as a standard merchant vessel, but which carried hidden guns.
Q ships accounted for fifteen U boats, for the loss of forty four of their own number.