Owing to separate commands in the different areas, difficulties arose in the co-ordination of the methods of protecting mer chant ships from submarines and by the middle of the year the losses in the Mediterranean became very serious. In August a British commander-in-chief was appointed to Malta as the single authority responsible for trade protection in that sea. A convoy system was started, under the escort of British and Japa nese destroyers and the toll of losses was gradually reduced. A further co-ordination of naval effort followed the meeting of the Allied Naval Council at Malta in November. During the year a British squadron of two battleships and a number of cruisers cruised in the Levant, watching the Dardanelles and co-operating with the Salonika force. On the Palestine coast, a flotilla of monitors, destroyers and gunboats took an active part in the battles of Gaza (q.v.), which led to the fall of Jerusalem (Nov. II).
During 1918 the mine became predominant as a counter to the submarine and a duel developed between the two weapons. The mine barrage in the Dover Straits was strengthened and with the patrol craft armed with every known anti-submarine device nine submarines were accounted for in that area during the early weeks of the year and it became evident to the German naval command that the passage of the Straits was virtually closed to them. They made two attempts to reopen the Straits. On Feb. 15 a destroyer flotilla raided the patrols at night, sank seven drifters and a trawler and escaped without being brought to action. On March 21 a similar raid was not so fortunate, the German flotilla being met by British destroyers. One German destroyer was rammed and cut in half by the "Botha," another was sunk by gunfire and the Germans were chased into Ostend. The "Botha" was torpedoed but reached Dover safely.
tilla returned to Dover next morning, its mission at Zeebrugge ac complished. At Ostend the blockships failed to find the entrance, but this was remedied a fortnight later, when a volunteer crew took the "Vindictive," of Zeebrugge fame, into Ostend and sank her in the entrance. These two brilliant actions did not entirely block the Flanders Coast bases, but their moral influence was great and they acted as an added inducement to the German submarines to shun the waters of the Dover command and to confine their efforts to gain the open sea to surmounting the lesser perils of the northabout route.