From August 5th to the 9th extensive anti-submarine operations were carried out to the westward of the Orkneys by a force consisting of nine destroyers, six sloops, five gunboats and a large number of patrol trawlers. The operations covered a very large area, the general idea being to compel any submarine intending to pass round the Shetland Islands or through the Fair Island Channel to submerge for a period that would exhaust her batteries and eventually bring her to the surface to recharge. The limited duration of darkness in northern latitudes assisted the operations of the hunting vessels. No _certain_ success was attained. A submarine was sighted on the 6th at 7 P.M., and a heavy explosion, under water, close to the sloop _Hollyhock_ at 9.30 P.M. on the same night might have been due to a submarine coming to grief, while another submarine was sighted at 10.30 A.M. on the 7th. Examination of a sailing vessel found in the vicinity of this latter submarine was unproductive. The 4th Light Cruiser Squadron left Scapa on August 6th to cruise off the Norwegian coast, and the battleships _Albemarle_ and _Russell_, of the 6th Battle Squadron, arrived at Scapa for practices, having left the Channel Fleet. On August 7th I returned in the _Iron Duke_ to Cromarty in order to meet the Prime Minister and Chancellor of the Exchequer who were about to visit Invergordon. At 9 A.M. on the 8th a wireless report was received in the _Iron Duke_ that a submarine was attacking a steamer off Rosehearty on the southern shore of the Moray Firth. The “duty” destroyer division was ordered to sea at once, and the remaining three available destroyers followed shortly afterwards. Meanwhile, the destroyer _Christopher_, already on patrol in the Moray Firth, reported herself in action at 11 A.M. with the submarine, which had submerged, the report stating that the merchant-ship had been sunk. The second destroyer on patrol, the _Midge_, assisted in the search for the submarine, as did the remaining destroyers and patrol trawlers, without result. At 10 A.M. the trawler mine-sweepers, which had been carrying out the usual routine sweep on the southern shore of the Moray Firth, reported the discovery of a mine-field to the northward of Banff, and several reports were received during the day of drifting mines being sighted along the coast and in the Firth. All destroyers were ordered in at 4 P.M., except the two on patrol and any others in touch with the submarine, and vessels remaining on patrol were given the limits of the mine-field as far as they had then been ascertained.