It was proposed that obsolete craft filled with concrete and manned by volunteers should proceed under their own steam and be sunk in the entrances of the canal opening into Zeebrugge harbour, and of the port of Ostend. A storming force was to disembark on Zeebrugge mole with demolition materials, bombs, and machine-guns, and destroy the seaplane sheds and other establishments. Simultaneously with the disembarkation of this force the viaduct connecting the curved arm of the mole to the mainland was to be blown up, thus preventing the enemy from despatching reinforcements to support the guns’ crews and defenders of the mole. While these assaults were in progress, a force of monitors and aerial bombing squadrons were detailed to maintain a furious bombardment by sea and air of all coastal batteries and works of military importance in the neighbourhood. The broad outline of the plan having been decided upon, the necessary blocking craft were selected from the Knackers’ Yards of the Navy, ships whose names conjure up forgotten commissions in tropic seas and a Navy fast passing into legend. _Thetis_, _Intrepid_, and _Iphigenia_ for Zeebrugge, _Sirius_ and _Brilliant_ for Ostend. To carry the assaulting parties to the mole, H.M.S. _Vindictive_ was brought from distant waters, and two Mersey ferry-craft, the _Iris_ and _Daffodil_, were commissioned to pass down to posterity as her consorts in this desperate undertaking. The ships were easier to select than the men. Invitations were sent to the Grand Fleet, the Home Port Depots, and the “Red” and “Blue” Marines to supply the requisite volunteers; the Royal Australian and Canadian Navies claimed their right to participate, and were also invited to send representatives. The response would have furnished a force sufficient to block half the ports of Germany had such an enterprise been contemplated. Eventually, however, the selections were made, and the flower of the Sea Service set its hand to the task. Acting Captain A. F. B. Carpenter, R.N., was appointed in command of the _Vindictive_, Commander Valentine Gibbs, R.N., to the _Iris_, and Lieutenant H. G. Campbell, R.N., to the _Daffodil_. In these three ships the storming and demolition parties were to embark, and the latter was also charged with the duty of pushing the _Vindictive_ alongside the mole and holding her there if her specially designed mole-anchors failed to grapple.