In November 1941, West Nohno became the first American merchant ship to be armed prior to the United States' entry into World War II.

In 1943, a civilian crewman aboard West Nohno was convicted of sedition for trying to incite a rebellion among members of the ship's crew and Naval Armed Guard.

In February 1944, she sailed from the United States for the final time, and was scuttled in June as part of the "gooseberry" breakwater off Utah Beach during the Normandy invasion, earning a battle star for the ship.

[7] Information on West Nohno's early career is incomplete, but through the end of 1920 the cargo ship sailed on a New York – Glasgow route.

[10] News items reported that West Nohno also visited Teneriffe,[11] Accra,[12] Las Palmas,[13] Grand-Bassam,[14] Seccondee,[15] and Saint Vincent.

By May 1941, now under ownership of the United States Maritime Commission (USMC) (a successor to the USSB),[5] the ship had been reactivated and was scheduled to sail in Red Sea service under the operation of American Export Lines.

While at the shipyard, West Nohno's wheelhouse and radio shack were reinforced with thick walls of concrete to protect against machine-gun bullets, and the ship was repainted "battleship gray".

[18] After her guns were installed, West Nohno had made her way to Sydney, Nova Scotia, by 27 December when she sailed as a part of transatlantic Convoy SC 86.

[19] Apparently suffering no major damage herself in the collision, West Nohno joined Arctic convoy PQ 9, which sailed on 1 February and arrived at Murmansk nine days later.

[20] The Chicago Daily Tribune reported that during this voyage, seaman James Orville Couchois had incited subordination and disloyalty among the crew.

The head of the Naval Armed Guard detachment aboard West Nohno reported Couchois' activities, as well as comments from other crew members on the ship.

[22] Couchois, who was the deck manager for the National Maritime Union of the Congress of Industrial Organizations, was convicted and sentenced to a prison term of five years.

In November 1944, The Christian Science Monitor reported that blockships dispatched from Boston, like West Nohno, had been loaded with "tons of sand and cement" and had been rigged with explosive charges before departing the port.

The "corncob" fleet was the group of ships intended to be sunk to form the "gooseberries",[29] shallow-water artificial harbors for landing craft.

[32] Poropat reports that the corncob ships traveled under cover of darkness and, stripped of all unnecessary equipment, carried no radios, having only a signal lamp (with a spare bulb) for communication.

[33] Naval Armed Guardsmen manned the guns on all the gooseberry ships to protect against frequent German air attacks; West Nohno's gunners assisted in shooting down several planes on 10 June.

[7] Harold T. Andrews was an ordinary seaman on the SS West Nohno on 15 September 1942 when the ship was in Suez, Egypt, There an engineer officer had been overcome by gases in a forepeak tank.