U.S. Navy service, World War I

Following an established practice all vessels built for the EFC were transferred to the U.S. Navy upon completion. On 11 January 1919 it was announced that West Compo would be the last of Portland-built vessels to be turned over to the Navy and there would be no further vessel transfers after January 31. Following completion of her sea trials, the freighter was delivered to USSB and then to the Navy on February 1. After examination the ship was commissioned into the NOTS on 3 February 1919, with Lieutenant Commander A. A. Modeer, USNRF, in command, assigned Identification number of 3912, and immediately proceeded for loading. After embarking a cargo of 82,266 barrels of wheat flour, West Compo left Portland on February 9 also carrying on board federal inspectors.^[8] The inspectors disembarked the vessel in Astoria after ascertaining the vessel performed satisfactorily on her loaded run down the Columbia River,^[9] while the freighter continued on her maiden journey. After a call at San Francisco, West Compo transited the Panama Canal on March 2, called at Norfolk in mid-March for bunkers before continuing on to the Mediterranean finally reaching Trieste on April 9.^{[10][11][2][Note 1]} After unloading her cargo and taking on sand ballast, she departed Italy on April 19 and arrived at Philadelphia via Gibraltar on May 15.^[12] She was decommissioned one week later, and returned to the USSB.^[2]

Commercial service

Following decommissioning from the Navy service, USSB allocated West Compo to Strachan Shipping Company to operate on their Southeast United States to France and Low Countries routes. The vessel cleared from Philadelphia on 27 May 1919 bound for Savannah where she loaded 20,665 bales of cotton and sailed for Le Havre on June 13.^[13][14] On her next trip to Europe she carried 7,100 tons of phosphate rock from Fernandina to Denmark.^[15] West Compo continued serving these routes until the end of her career. For example, in August 1920 she again carried 7,100 tons of hard rock phosphate from Florida ports of Jacksonville and Fernandina to Bremen and Fredericia.^[16] On her last return trip from Stettin and Brest she became disabled soon after leaving the French port on 11 April 1921 and had to be put back with a help of the USSB tug for quick repairs. West Compo arrived at Savannah on May 4 where she was returned by Strachan Shipping to the USSB due to overabundance of tonnage and scarcity of cargo. The freighter remained moored in Savannah for the next year and a half. In November 1922 it was announced the ship together with several other vessels was set to be relocated to Eustis to be laid up.^[17] The freighter was first towed to Charleston in early December 1922 where she remained for the next eight month before finally arriving in Newport News on 15 August 1923 to become part of the USSB reserve fleet.^[18][19]

In November 1929 the Shipping Board contemplated reconditioning of six ships, including West Compo, in anticipation of increased cotton, wheat and flour traffic out of Gulf ports to Europe, but that work was never performed.^[20][21] In early September 1932 the Shipping Board decided to scrap 124 World War I era vessels in its possession, including West Compo, to alleviate significant tonnage overabundance. As a result, all the vessels were removed from the U.S register of shipping.^[22] In October 1932 it was announced the whole lot of these vessels was sold to the Boston Iron and Metal Company of Baltimore for $1.51/ton of recoverable of material which was believed at the time to be over 350,000 tons. The disposition was estimated take about three years to complete and West Compo was eventually scrapped in April 1936.^[23][1]