This then was the plan of campaign, one of the most daring ever conceived, and all the more so in face of the difficulty of keeping it concealed from the enemy during the long period of preparation--a difficulty enhanced in that it was not only necessary to inform each man of his particular role, but of the particular objectives of each attack and the general outline of the whole scheme. That was unavoidable since it was more than likely that, during any one of the component actions, every officer might be killed or wounded and the men themselves become responsible. Nor was it possible, even approximately, to fix a date for the enterprise, since this could only be carried out under particular conditions of wind and weather. Thus the night must be dark and the sea calm; the arrival on the other side must be at high water; and there must above all things be a following wind, since, without this, the smoke-screens would be useless. Twice, when all was ready, these conditions seemed to have come, and twice, after a start had been made, the expedition had to return; and it was not until April 22, 1918, that the final embarkation took place. By this time Vice-Admiral Keyes had succeeded {230} Vice-Admiral Bacon in command of the Dover Patrol; and he was therefore in personal charge of the great adventure that he had initiated and planned with such care. Every man under him was not only a volunteer fully aware of what he was about to face, but a picked man, selected and judged by as high a standard, perhaps, as the world could have provided. Flying his own flag on the destroyer _Warwick_, Admiral Keyes had entrusted the _Vindictive_ to Acting Captain A. F. B. Carpenter, the _Iris_ and the _Daffodil_ being in the hands respectively of Commander Valentine Gibbs and Lieutenant Harold Campbell. The Marines, consisting of three companies of the Royal Marine Light Infantry and a hundred men of the Royal Marine Artillery, had been drawn from the Grand Fleet, the Chatham, Portsmouth, and Devonport Depots, and were commanded by Lieutenant-Colonel Bertram Elliot. The three block-ships that were to be sunk at Zeebrugge, the _Thetis_, _Intrepid_, and _Iphigenia_, were in charge of Commander Ralph S. Sneyd, Lieutenant Stuart Bonham-Carter, and Lieutenant E. W. Billyard-Leake; while the old submarine _C3_ that was to blow up the viaduct was commanded by Lieutenant R. D. Sandford. In control of the motor-launches allotted to the attack on Zeebrugge, was Admiral Keyes' flag-captain, Captain R. Collins, those at Ostend being directed by Commander Hamilton Benn, M.P.--the operations at the latter place being in charge of Commodore Hubert Lynes. Also acting in support was a large body of coastal motor-boats under Lieutenant A. E. P. Wellman, and a flotilla of destroyers under Captain {231} Wilfred Tomkinson, the general surveying of the whole field of attack--including the fixing of targets and firing-points--being in the skilful hands of Commander H. P.