Western Sea was a steam cargo ship built in 1918 by J. F. Duthie and Company of Seattle for the United States Shipping Board as part of the wartime shipbuilding program of the Emergency Fleet Corporation (EFC) to restore the nation's Merchant Marine.

Renamed SS Western Sea while under construction, she was launched on 25 May 1918 and completed late in June 1918.

Upon her completion, the Shipping Board transferred her immediately to the U.S. Navy for use during World War I.

After loading 1,000 tons of pyrite at Bordeaux, Western Sea proceeded to Halifax, Nova Scotia, Canada, and then to New York City, where she arrived on 24 November 1918.

On 7 February 1919, she departed Rotterdam to return to the United States, arriving at New York City on 1 March 1919.