In 1914 King George V and Queen Mary travelled on the ferry "S.S. Daffodil" from Wallasey to Liverpool. During the First World War the steamers "Iris" and "Daffodil" were taken out of service from Wallasey to be used as troop ships in the naval raid on Zeebrugge in Belgium. The ferries had a shallow draft, allowing them to skim over the mines floating beneath the surface, and were robust enough to approach the heavily defended mole curling into the North Sea. They both saw action, which was described on 24 April 1918 by Vice–Admiral Sir Roger Keyes of the Royal Navy in a message to the ferries' manager: