As early as 1917 the Dominion had begun to consider post-war Naval requirements. In 1919 Admiral Jellicoe undertook a survey of the Empire's naval defences. His report recommended that New Zealand develop a force of three 'Fleet Units' that could easily be integrated with similar units of the Royal Australian Navy or the Royal Navy (RN) in the event of war. A Fleet Unit would comprise one light cruiser, two destroyers and two submarines, supported by HMS PHILOMEL as a depot ship. Jellicoe recommended that New Zealand initially obtain three cruisers and six submarines, with the destroyers to come later. However, the government sought only a modern replacement for PHILOMEL. HMS CHATHAM arrived in New Zealand in 1921 to become the flagship. HMS CHATHAM is remembered in the form of New Zealand's premier soccer trophy, which was donated by her crew. Jellicoe returned to New Zealand as Governor General from 1920 to 1924.