She entered service after conversion in May 1922 and was sent to Malta and in September, evacuated Greek refugees from the Burning of Smyrna. In January 1927, she left Malta for Singapore for deployment to the China Station, returning to Portsmouth in December before rejoining the Mediterranean Fleet. On 20 February 1928 "Maine" broke her moorings during a storm at Malta and was grounded. In 1935 she attended King George V's Silver Jubilee Fleet Review off Spithead, where she was used to entertain important guests, her Red Cross markings having been removed for the occasion. Between July 1936 and July 1938, she participated in the evacuation of refugees from the Spanish Civil War, carrying a total of 6,574 refugees of 41 nationalities to safety.