 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 went through 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 @-@ <unk> 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 . 
