Other attempts to dodge the sights of a submarine included steaming in a zigzag course and limiting the use of wireless telegraphy. The latter could be intercepted and used to reveal the exact location of an enemy ship.
Armed Defences were shored up with heavier guns and additional look out and gunnery training was provided by RNR Officers and extended to cadets and apprentices in August 1917.
But perhaps the most successful deterrent to the U-boat commanders was the sight of a mighty convoy. Much favoured by David Lloyd George, the use of convoys became much more widespread as the war continued.