Vice-Admiral Sir Roger Keyes devoted personal attention and time to working out the plan of operations and the preparation of the personnel and material.  Rear Admiral Cecil F. Dampier, second in command of the Dover flotilla, and Commodore Algernon Boyle, chief of staff, gave considerable assistance.

When, as vice-admiral of the Dover patrol, Admiral Keyes first began to prepare for the operation, it became apparent that without an effective system of smoke screening such an attack could hardly hope to succeed.  The system of making smoke previously employed in the Dover patrol was unsuitable for a night operation, as this production generated a fierce flame, and no other means of making an effective smoke screen was available.  Nevertheless Wing Commander Brock, at last devised the way.

The commander-in-chief of the Grand Fleet, Admiral Beatty, sent to Admiral Keyes a picked body of officers and men.  Support also was received from the neighboring commands at Portsmouth and the Nore, the adjutant general, Royal Marines, and the depot at Chatham.  The rear-admiral commanding the Harwich force sent a flotilla leader and six destroyers, besides protecting the northern flank of the area in which operations were to be conducted.

To afford protection at a certain point in the route and to maintain the aids to navigation during the approach and retirement of the expedition, a force consisting of the flotilla leaders Scott and the destroyers Ulleswater, Teazer and Stork, and the light cruiser Attentive, flying the pennant of Commodore Boyle, was organized.  This force, as it developed, was instrumental in patroling and directing the movements of detached craft in both directions, and relieved Admiral Keyes of all anxiety on that score.

At the moment of departing the forces were disposed as follows: 

In the Swim—­For the attack on the Zeebrugge Mole:  Vindictive, Iris, Gloucester.  To block the Bruges canal:  Thetis, Interprid and Iphigenia.  To block the entrance to Ostend:  Sirius and Brilliant.

At Dover—­Warwick, flagship of Vice-Admiral Keyes; Phoebe, North Star, Brigadier, Trident, Mansfield, Whirlwind, Myngs, Velox, Morris, Moorsom, Melpomene, Tempest and Tetrarch.

To damage Zeebrugge—­Submarines C-1 and C-3.

A special picket boat to rescue crews of C-1 and C-3.

Minesweeper Lingfield to take off surplus steaming parties of block ships, which had 100 miles to steam.

Eighteen coastal motorboats.

Thirty-three motor launches.

To bombard vicinity of Zeebrugge—­Monitors Erebus and Terror.

To attend monitors—­Termagant, Truculent, and Manly.

Outer patrol off Zeebrugge—­Attentive, Scot, Ulleswater, Teazer and Stork.

At Dunkirk—­Monitors for bombarding Ostend:  Marshal Soult, Lord Clive,
Prince Eugene, General Sraufurd, M-24 and M-26.

For operating off Ostend—­Swift, Faulknor, Matchless, Mastiff and Afridi.