The revised Combined Operations plan required one destroyer to ram the dock gates and a number of smaller craft to transport the commandos. The Royal Navy would therefore provide the largest contingent for the raid, under the overall command of the senior naval officer, Commander Robert Ryder. The ship selected to ram into the dock gates was , commanded by Lieutenant Commander Stephen Halden Beattie. "Campbeltown" was a First World War destroyer and had previously been in the United States Navy. She had come into RN service in 1940 as one of 50 destroyers transferred to the United Kingdom under the destroyers-for-bases deal.