When the Japanese attacked
Pearl Harbor in December 1941,
Chaumont was on one of her regular voyages from
Hawaii to Manila, carrying sailors, civilian workmen, and cargo that included munitions. She was diverted as part of the "
Pensacola Convoy" to
Brisbane then, after a period of reloading the convoy's men and cargo, she proceeded to
Darwin, Australia with Navy supplies where she discharged her passengers and cargo on 5 January 1942. After returning to Brisbane she went to
Sydney then
Wellington, New Zealand and
Balboa before returning to San Francisco on 29 March 1942. After two runs to Pearl Harbor, the now elderly transport was assigned to service between
Seattle and
Alaska, bringing men and supplies to assist in the defense of the
Aleutians. Selected in March 1943 for conversion to a
hospital ship,
Chaumont was decommissioned in August for conversion at Seattle. Renamed
Samaritan (AH-10), she was recommissioned in March 1944. Between 25 March and 11 May, she made two voyages from San Francisco to Hawaii, with passengers outward bound and patients homeward bound. Arriving in
Honolulu a third time 11 May, she continued to
Kwajalein, where from 17 June to 1 July, she treated casualties from the
Saipan invasion. On 8 July she arrived off Saipan itself to embark patients for evacuation to
Noumea,
New Caledonia, from which she returned to Saipan 1 August for two weeks of duty as a receiving hospital. , February 1945
Samaritan evacuated patients from
Guam to
Guadalcanal, and from
Peleliu to the
Russell Islands in August and September 1944. After a brief overhaul at
Espiritu Santo, she served as base hospital at
Ulithi until 16 February 1945, when she sailed for
Iwo Jima. She arrived off the bitterly engaged island 20 February, and sailed 2 days later with 606 patients on board for Saipan. On the second day out, eight men were buried at sea. The hospital ship returned to Iwo Jima 25 February 1945 to embark patients for transportation to
Guam on the first of two such voyages. She arrived at Ulithi 2 April, and a week later got underway for embattled
Okinawa. Arriving 13 April, she received casualties at the beach during the daytime and withdrew at night to the transport areas offshore, alternating her stays at Okinawa with evacuation voyages to Saipan until 1 July, when she sailed from Saipan for Pearl Harbor. Here she took patients from several island hospitals on board, sailed to San Francisco, and on 10 September back to Pearl Harbor thence
Sasebo, where she provided hospital facilities to occupation forces until 15 March 1946. ==Decommissioning==