At the start of WWI the powerful British Fleet was effectively driven out by a few German submarines to find safer hiding places far from the North Sea. This opened up the whole of the East coast of England to hostile attack by air and sea. British airships were to prove a formidable deterrent to the U-boat while performing reconnaissance, patrolling, mine-hunting and convoy escort duties. Hunting subs over the North Sea was cold work for English dirigible crews. Lewis gunners, who perched out in the open on platforms under the propellers while other crew members looked for dark shapes or oil slicks of submerged subs. When they found a U-boat they guided Destroyers; depth charge attacks and often dropped their own bombs. The NS class (North Sea) were largest and most effective nonrigid airships in British service. These had a gas capacity of 360,000 cubic feet, a crew of 10 and an endurance of 24 hours. Six 230 pound bombs were carried, as well as three to five machine guns.
