We figured that, to make the patrol system work with complete success, it would be necessary to have one destroyer for every square mile. The area of the destroyer patrol off Queenstown comprised about 25,000 square miles; it is apparent that the complete protection of the trans-Atlantic trade routes would have taken about 25,000 destroyers. And the British, as I have said, had available anywhere from four to fifteen in this area. The destroyer flotilla being so small, it is not surprising that the German submarines were making ducks and drakes of it. The map of the sinkings which took place in April brings out an interesting fact: numerous as these sinkings were, very few merchantmen were torpedoed, in this month, at the entrance to the Irish Sea or in the English Channel. These were the narrow waters where shipping was massed and where the little destroyer patrol was intended to operate. The German submarines apparently avoided these waters, and made their attacks out in the open sea, sometimes two and three hundred miles west and south of Ireland. Their purpose in doing this was to draw the destroyer patrol out into the open sea and in that way to cause its dispersal. And these tactics were succeeding. There were six separate steamship "lanes" by which the merchantmen could approach the English Channel and the Irish Sea. One day the submarines would attack along one of these lanes; then the little destroyer fleet would rush to this scene of operations. Immediately the Germans would depart and attack another route many miles away; then the destroyers would go pell-mell for that location. Just as they arrived, however, the U-boats would begin operating elsewhere; and so it went on, a game of hide and seek in which the advantages lay all on the side of the warships which possessed that wonderful ability to make themselves unseen. At this period the submarine campaign and the anti-submarine campaign was really a case of blindman's buff; the destroyer could never see the enemy while the enemy could always see the destroyer; and this is the reason that the Allies were failing and that the Germans were succeeding. IV To show how serious the situation was, let me quote from the reports which I sent to Washington during this period. I find statements like these scattered everywhere in my despatches of the spring of 1917: "The military situation presented by the enemy submarine campaign is not only serious but critical." "The outstanding fact which cannot be escaped is that we are not succeeding, or in other words, that the enemy's campaign is proving successful."