At 11 A.M. the Iron Duke, with the Dreadnought Battle Fleet, was in Lat. 56.22 N., Long. 0.0; the 3rd Battle Squadron and 3rd Cruiser Squadron were about 35 miles and the 5th Battle Squadron about 70 miles to the southward, the Battle Cruiser Fleet being well to the south-eastward in the direction of Terschelling, and, as appeared later, having evidently only just barely missed cutting the enemy off from his base. The Battle Fleet stood on to the south-eastward until the afternoon, when it became evident that the Germans had escaped to their bases, and the Fleet then turned to the northward and shaped course for the bases, arriving on the 26th.
On returning, my opinion was asked by the Admiralty as to the steps which could be taken to minimise the danger of a recurrence of such raids on unfortified towns on the south-east coast as that of the 25th. Although they inflicted no military damage, they were undoubtedly a great annoyance owing to the alarm of the inhabitants, and might result in much loss of life. I suggested that the placing of the 3rd Battle Squadron in the Humber or in the Thames might act as a deterrent, and in any case would make it necessary for the enemy to bring heavy ships, which would give us an opportunity of inflicting injury by submarines or by the ships of the Grand Fleet, if, by good fortune, we happened to be cruising sufficiently far to the southward at the time. The presence of the squadron in southern waters would be useful, also, in the unlikely event of landing raids, and would provide a good backing to the Harwich force, although the difficulties of movement, due to the frequent mine-laying by enemy submarines in southern waters, were considerable. I pointed out that since the arrival of the 5th Battle Squadron and the other new ships, the 3rd Battle Squadron was no longer required to strengthen the Grand Fleet; the ships of the “Revenge” class were also approaching completion. The proposal was adopted, and the 3rd Battle Squadron and 3rd Cruiser Squadron sailed for the Humber on the 29th, en route to the Medway. On that port the 3rd Battle Squadron was based in future, the ships of the 3rd Cruiser Squadron being gradually withdrawn for service in foreign waters. The Admiralty also stationed some of the monitors in the more important undefended ports.
During the month of April a policy, suggested by me, of placing the Captains (D) in flotilla leaders instead of in light cruisers, was adopted. This was made possible by the completion of several vessels of the class. The object was to add the light cruisers thus released to our all too slender light cruiser force.
The average weekly figures for the 10th Cruiser Squadron during April were:
Number of ships intercepted, 40; number sent in, 10; number of ships on patrol, 12; number absent at ports or en route to or from patrol, 9; number on special service, 1.
A very considerable amount of mist and fog was experienced during the month, and gales on the 8th, 16th and 24th.
On May 2nd forces left for an aerial operation in the vicinity of the Horn Reef. The operation was covered by the Grand Fleet. One of its objects was, as before, to attract the attention of the enemy’s naval forces to the North Sea. Even if no enemy force were actually drawn out, it was expected that the presence of the Grand Fleet in southern waters would soon become known to the enemy from neutral sources, with the result that vessels of the High Sea Fleet, intended for operations in the Baltic, might be detained in, or brought back to, North Sea ports. From information obtained subsequently from reliable sources, it appeared that the operation produced the intended result. Between the afternoon of May 2nd and daylight on the 3rd the Fleet left its bases.
The 1st Light Cruiser Squadron, with 16 destroyers convoying the sea-plane-carriers Vindex and Engadine, proceeded to a position just north of the Horn Reef, arriving at dawn on May 4th; the objective of the sea-planes was the zeppelin sheds at Tondern. The mine-layer Abdiel proceeded to lay mines on the night of the 3rd–4th to the southward of the Vyl Lightship on the expected track of enemy vessels en route to the North Sea via the Horn Reef. The mine-layer Princess Margaret was directed to lay mines on the same night across the expected route taken by enemy vessels if coming out along the route passing the West Frisian Islands. Both mine-fields were completed without any interference on the part of the enemy.
Three submarines were sent to positions off the Horn Reef, three to positions off the Vyl light vessel, and three to positions off Terschelling, to arrive on the evening of the 3rd.[E]
[E] Two of our submarines collided while submerged off the Horn Reef, one being slightly damaged.