But another point, widely separated from British waters, also made a powerful plea for consideration. In the Mediterranean the submarine campaign was still a menace. The spring and early summer of 1918 witnessed large losses of shipping destined to southern France, to Italy, and to the armies at Salonika and in Palestine. Austrian and German submarines, operating from their bases at Pola and Cattaro in the Adriatic, were responsible for this destruction. If we could pen these pests in the Adriatic, the whole Mediterranean Sea would become an unobstructed highway for the Allies. A glance at the map indicated the way in which such a desirable result might be accomplished. At its southern extremity the Adriatic narrows to a passage only forty miles wide--the Strait of Otranto--and through this restricted area all the submarines were obliged to pass before they could reach the water where they could prey upon Allied commerce. For some time before the Allied Naval Council began to consider the use of the American subchasers, the British navy was doing its best to keep submarines from passing this point. A defensive scheme known, not very accurately, as the "Otranto barrage" was in operation. The word "barrage" suggests an effective barrier, but this one at the base of the Adriatic consisted merely of a few British destroyers of ancient type and a large number of drifters, which kept up a continuous patrolling of the gateway through which the submarines made their way into the Mediterranean. It is no reflection upon the British to say that this barrage was unsatisfactory and inadequate, and that, for the first few months, it formed a not particularly formidable obstruction. So many demands were made upon the British navy in northern waters that it could not spare many vessels for this work; the Italian navy was holding the majority of its destroyers intact, momentarily prepared for a sortie by the Austrian battle fleet; the Otranto barrage, therefore, important as it was to the Allied cause, was necessarily insufficient. The Italian representatives at the Allied Council made a strong plea for a contingent of American subchasers to reinforce the British ships, and the British and French delegates seconded this request.