The amount of bombing work carried out in 1917 cannot, of course, compare with that accomplished during 1918, when production had got into its stride and the number of machines available was consequently so very much larger.
Whether it was due to our aerial attacks on Bruges that the German destroyers in the autumn months frequently left that base and lay at Zeebrugge cannot be known, but they did so, and as soon as we discovered this fact by aerial photographs, plans were laid by Sir Reginald Bacon for a combined naval and aerial night operation.

The idea was for the aircraft to bomb Zeebrugge heavily in the vicinity of the Mole, as we ascertained by trial that on such occasions the enemy's destroyers left the Mole and proceeded outside the harbour.

There we had our coastal motor boats lying off waiting for the destroyers to come out, and on the first occasion that the operation was carried out one German destroyer was sunk and another believed to have been damaged, if not also sunk, by torpedoes fired by the coastal motor boats, to which very great credit is due for their work, not only on this, but on many other occasions; these boats were manned by a very gallant and enterprising personnel.
Numerous other operations against enemy destroyers, torpedo boats and submarines were carried out during the year, as recounted in Sir Reginald Bacon's book, and in the autumn, when supplies of the new pattern mines were becoming available, some minelaying destroyers were sent to Dover; these vessels, as well as coastal motor boats and motor launches, were continually laying mines in the vicinity of Zeebrugge and Ostend with excellent results, a considerable number of German destroyers and torpedo boats working from Zeebrugge being known to have been mined, and a fair proportion of them sunk by these measures.
In addition to the operations carried out in the vicinity of the Belgian coast, the Dover force constantly laid traps for the enemy destroyers and submarines in waters through which they were known to pass.
Lines of mined nets laid across the expected track of enemy vessels was a device frequently employed; submarines, as has been stated, were used on the cross-Channel barrage to watch for the passage of enemy submarines and destroyers, and everything that ingenuity could suggest was done to catch the German craft if they came out.
Such measures were supplementary to the work of the destroyers engaged on the regular Dover Patrol, the indomitable Sixth Flotilla.
A great deal depended upon the work of these destroyers.

They formed the principal, indeed practically the only, protection for the vast volume of trade passing the Straits of Dover as well as for our cross-Channel communications.

When the nearness of Zeebrugge and Ostend to Dover is considered (a matter of only 72 and 62 miles respectively), and the fact that one and sometimes two German flotillas, each comprising eleven large and heavily armed torpedo-boat destroyers, were usually based on Bruges, together with a force of large modern torpedo boats and a very considerable number of submarines, it will be realized that the position was ever one of considerable anxiety.