the King's Medal, awarded for "gentlemanly bearing, character, good influence among his fellows and officer-like qualities". Promoted to midshipman on 1 January 1918, he was posted to Britain where, in April, he was appointed to serve in the Royal Navy's (RN) Grand Fleet with the dreadnought . The ship did not see combat while he was on board. Between the wars In February 1919, Waller was assigned to the light cruiser HMAS Melbourne, and two months later returned to Australia. He transferred to the light cruiser HMAS Sydney as an acting sub-lieutenant in September; his rank was made substantive the following month. In April 1920 he was again posted aboard Melbourne. Promoted to lieutenant in March 1921, he underwent further training in Britain before returning to join the staff of the RANC. Waller married Nancy Bowes, a minister's daughter, on 7 April 1923 in the Sydney suburb of Lewisham; the couple had two sons, Michael and John. In April 1924, he was posted to the light cruiser HMAS Adelaide. Later that year, he began training as a signals officer in England; his classmates included Lord Louis Mountbatten. Waller finished at the top of the advanced course and, in May 1926, took charge of the Signals and Wireless-Telegraphy School at Flinders Naval Depot in Westernport, Victoria. From 1928 to 1930, he served with the RN as a signals officer aboard the destroyer HMS Broke. He was promoted to lieutenant commander in March 1929. By this stage of his career, Waller had acquired a strong reputation for his communications work. In July 1930, he was posted aboard the Royal Australian Navy's (RAN) flagship, the heavy cruiser HMAS Australia, as squadron signals officer. He continued in this role upon transferring to Australias sister ship, HMAS Canberra, in May 1931. In early 1932, he was assigned to the Navy Office in Melbourne, returning to Canberra as squadron signals officer in August 1933. He was promoted to commander in June 1934 and the following month became executive officer of the RANC. Departing the college in July 1936, he returned to England and spent six months in the British Naval Intelligence Division. A stint as executive officer of the repair ship HMS Resource followed. In November 1937, Waller was given his first command at sea, the RN destroyer HMS Brazen. His ship handling was criticised early on, but was soon reported by his superiors as having