Complex sentence: After four years of duty at the Admiralty, Dewar returned to sea in 1922, being appointed on 9 May to command the "C" class cruiser HMS "Calcutta" on the North America and West Indies Station.
Split into simpler sentences: After four years of duty at the Admiralty, Dewar returned to sea in 1922. He was appointed on 9 May to command the "C" class cruiser HMS "Calcutta" on the North America and West Indies Station.