Q-Ships, one of the most closely guarded secrets of the war, were heavily armed merchant ships with concealed weapons. Their purpose was to lure German U-Boats to make surface attacks, thereby giving the Q-ship a chance to open fire and sink the surprised U-Boat. This exciting film details much more then just the Q-Ships. It covers the devastating success of the German U-Boats in hampering British trade. The escalation to unrestricted submarine warfare, targeting any merchant vessel in the Atlantic. The allied shift to convey travel for protection, the use of underwater hydrophones to detect u-boats and lastly the deployment of the Q-Ships. The Q-ships crew were portrayed by actual British Naval crewman and officers from WWI.