In October 1939 the 10,852 ton Monowai was converted into an Armed Merchant Cruiser (AMC) after initially serving in the South Pacific as a convoy escort. She was attacked by gunfire from a Japanese submarine off Fiji in January 1942 but escaped undamaged. In February 1944 she was converted to a Landing Ship Infantry (LSI) making voyages to Port Said and Italy. From there she went to the Solent to be prepared for the Normandy Landings where she carried 30,000 troops across to France, making a remarkable 20 voyages to the beaches. From November 1944 to March 1945 the S S Monowai carried a further 43,000 troops between Southampton and Le Havre, spending the rest of the war years repatriating prisoners of war to Australasian shores. In 1946 she was refitted in Sydney and returned to service in 1949. In 1960 she was scrapped in Hong Kong.