From fisheries patrols to Kingsmill's staff

Nelles entered Canadian maritime service through the Fisheries Protection Service in 1909 aboard CGS Canada, then served in HMCS Niobe before going to the Royal Navy for experience that the small RCN could not provide. By December 1911 he was aboard HMS Dreadnought, and in 1914 he joined HMS Suffolk on the North America and West Indies Station. Suffolk protected British interests during the civil war in Mexico and, after the First World War began, patrolled Atlantic shipping routes between Bermuda and Halifax. Recalled to Ottawa in April 1917, Nelles became flag lieutenant to Sir Charles Kingsmill, formally the director of the Naval Service of Canada. The wartime service Kingsmill was trying to build had begun with two old cruisers and converted civilian and commercial vessels. These appointments taught Nelles presence, diplomacy, trade protection, and naval administration while testing an officer already being prepared for senior Canadian command.