On the 15th Submarines D 7 and E 30 left for the Kattegat to operate at the northern end of the Sound and off Anholt Island. One German merchant-steamer was intercepted and sunk outside territorial waters off the Kullen on the 22nd by E 30. On the 18th another submarine was sent to operate off Goteberg in Sweden. She returned on the 25th, not having sighted any enemy vessels.
On the same day a reliable report was received that an exceptionally large force of enemy submarines was now operating in the North Sea, and additional precautions were taken at all the bases to strengthen the patrols and to protect inward- and outward-bound vessels. The Vice-Admiral of the 10th Cruiser Squadron was warned to be ready to move all his patrol lines to given alternative positions, and on the 19th was directed to move his ships to the most western of these lines. Precautions against mine-laying by submarines were also taken, and the waters to the eastward of the “Long Forties,” through which the Fleet usually passed when on passage south, were examined by the Fleet mine-sweepers, protected by destroyers, on the 21st and subsequent days. These vessels searched without result on the 22nd for a submarine which was being chased by a patrol vessel in this neighbourhood.
On the 21st the Donegal and two destroyers were sent to the vicinity of the entrance to Bergen to intercept a steamer which, it was thought, had passed through the 10th Cruiser Squadron blockade during a fog. The ship however, called later at Kirkwall, and the force was recalled.
On the 23rd the first of a series of deep mine-fields in the Moray Firth, which I had requested might be laid with the object of catching enemy submarines, was placed in position by the mine-layer Biarritz.
On the 24th the Donegal and an armed boarding-steamer were sent to patrol off Stadlandet with a view to intercepting ships engaged in the iron ore trade from Narvik. This, as before stated, was one of the few positions at which ships were obliged for navigational reasons to leave territorial waters.
On the 24th the 4th Light Cruiser Squadron, with destroyers, which had been at Rosyth, left for another search off the Norwegian coast from the Naze to Udsire, and thence to Scapa. The search was unproductive.
On the 26th two submarines were despatched to operate against enemy submarines off the Norwegian coast, and, on the same date, the 1st Light Cruiser Squadron, with six destroyers, left, via the searched channel, to carry out a reconnaissance to the southward of the German North Sea mine-field. The squadron proceeded as far east as Long. 6 E., but, unfortunately, sighted nothing.
The Broke and 12 destroyers left on the 27th to search for a submarine reported to have been sighted to the eastward of the Pentland Firth, and returned on the 28th, not having seen her; but on the 27th Trawler Unit No. 42, working from Peterhead, reported having engaged and sunk a submarine at 12.45 P.M. in Lat. 57.10 N., Long. 1.20 E., thus adding one more success to the record of this patrol. On the 30th Fleet-sweeper Gentian was missed, in a position about 40 miles due east of the Pentland Firth, by a torpedo fired evidently by the submarine that had been hunted on the 28th. A half flotilla and sea-planes were sent out to search, and a submarine was sighted at 3.45 P.M. near the position given, but she dived and got clear away.
The movements of the Fleet between the time of leaving and returning to the bases in connection with the Battle of Jutland are given in Chapter XI., but some mention may be made of an incident which occurred on the night of May 31st. A report was received at Scapa that an enemy raider might be attempting to escape into the Atlantic. The Vice-Admiral of the 10th Cruiser Squadron was directed to assume a patrol north of the Shetlands in accordance with a plan which had been pre-arranged to meet such a case. On June 3rd, after the return of the Fleet to its bases, light cruisers were sent out to patrol to the north-westward of the Orkneys, and the 10th Cruiser Squadron was then directed to fall back to a position farther west to form a second patrol line. Nothing came of the matter.
During the month of May the weekly average results of the 10th Cruiser Squadron showed: Number of vessels intercepted, 55, besides 17 trawlers; number sent in, 18; number of ships on patrol, 11; number absent at ports or en route to or from patrol, 9; number on special service, 2.