The mine-sweepers, which had swept ahead of the Battle Fleet when on the southerly course, acted as a submarine screen during the passage to the northward. During the night of the 16th–17th the 3rd Cruiser Squadron was detached to Cromarty to coal, the 10th Cruiser Squadron to Scapa to coal, and to resume the northern patrol, and the 6th Battle Squadron, the 2nd Flotilla mine-sweepers and 3rd Battle Squadron proceeded to Scapa to fuel. _August 17th._--At 7.15 A.M. the Dreadnought Battle Fleet altered course to pass through the Fair Island Channel, and the 1st Battle Cruiser Squadron rejoined. The 4th Flotilla, which had been disposed astern during the night, resumed station as a submarine screen at daylight. The Battle Fleet zigzagged as usual throughout daylight. At noon the _Iron Duke’s_ position was Lat. 58.59 N., Long. 1.35 E. At midnight, Lat. 59.27 N., Long. 2.25 W., and at 8 A.M. the 18th, Lat. 58.44 N., Long. 4.47 W. The 2nd Cruiser Squadron on the northerly sweep sighted only neutral vessels and proceeded to work in an area designated as No. 5 (eastward from Kinnaird Head). Noon position, Lat. 58.42 N., Long. 3.0 E. This area, No. 5, was designed to cover the approach to the Pentland Firth, both for blockade purposes and as an outpost position for the Fleet at Scapa. At this time, the northern and central parts of the North Sea were divided into certain numbered areas in which cruisers could be directed by wireless to work without the necessity of making a long signal. The various areas were approximately placed as follows: Area No. 1.--Covering the route round the north end of the Shetland Islands from the southward and eastward. Area No. 2.--Covering the Fair Island Channel to south-eastward, working down to the line Kinnaird Head--Udsire. Area No. 3.--South-eastward from the N.E. end of the Orkneys to Lat. of Kinnaird Head, with a width of about 50 miles from the line Noss Head--Kinnaird Head. Area No. 4.--South-eastward 120 miles from the line Kinnaird Head--Udsire Lighthouse between 70 and 140 miles from Kinnaird Head. Area No. 5.--South-eastward 120 miles from the line Kinnaird Head--Udsire Lighthouse, between Area 4 and Norwegian territorial waters. Area No. 6.--South-eastward 120 miles from the line Kinnaird Head--Udsire Lighthouse, between 20 and 70 miles from Kinnaird Head. Area No. 7.--Between Lat. 55.20 N. and 57.50 N. and between 50 and 150 miles from the English coast.