Further craft were required for assisting to locate the destination, for dealing with enemy vessels putting to sea during the attack, for defending our ships against other enemy vessels already at sea, for assisting to tow some of the smaller units across the seas, for rescuing the crews of the blockships, and for various diversionary measures. The latter included long-range bombardments from the sea and subsidiary attacks on the Mole, the units required being monitors and their attendant craft and fast motor boats. Other diversionary measures, not requiring naval vessels for their accomplishment, were bombing attacks by aircraft and bombardments from our shore guns. [Illustration: ONE OF THE MONITORS. H.M. SHIPS IRIS (RIGHT) AND DAFFODIL.] The aircraft were intended to attract the attention of those on duty in an overhead direction, whilst encouraging the remainder to keep under cover. The long-range bombardments would tend to keep the enemy's larger batteries occupied in expending ammunition in their endeavour to locate and silence our guns. Subsidiary attacks, carried out by fast motor craft against the Mole, and against German vessels berthed at its inner side, were calculated to confuse the situation as far as the enemy were concerned. It was arranged that the R.M.A. siege guns on the northern flank of the Allied army should bombard for the purpose of simulating a prelude to a land attack. The reason for the employment of one hundred and sixty-two vessels, not including aircraft, will now be somewhat more clear. The various classes comprised cruisers, submarines, ferry-boats, monitors, destroyers, motor launches, small motor boats of a fast type, {85} and one ordinary ship's steamboat; the latter was to be used in connection with rescuing the crews of the submarines. With the exception of the blockships, storming vessels, and submarines, the majority of the craft were drawn from the forces attached to the Dover Command; these latter, being in full commission already, did not require new officers and men to be specially appointed for our purposes. Seven French torpedo craft and four French motor launches were included in the operation. The aircraft were drawn from the 61st and 65th Wings of the Royal Air Force. Space does not admit of describing the work of all these units in detail, but it may be of interest to mention one or two. [Sidenote: Precautions Against Fatigue]