In November 1944, while serving as Japanese transport Seisho Maru during World War II, she was sunk by U.S. Navy submarine Sunfish.

[2] West Caruth was inspected by the 12th Naval District of the United States Navy after completion for possible use as a service collier and was assigned the identification number of 3850.

[8] In 1923,[2] West Caruth was sold to the North Devon Steamship Company and operated as tramp steamer Exmoor under the British flag.

Four years later, she was renamed Seisho Maru as a part of Oguma Shoten Gomei Kaisha of Tsurumi under Japanese registry.

[9] Another notice in November 1933 noted her impending return to Los Angeles, where she was scheduled to take on a load of borax and scrap brass.

[11] During World War II, Seisho Maru served as an army transport,[12] but sources reporting her movements are incomplete.

[13] Seisho Maru and seven other ships formed convoy MI-27 which departed Moji for Miri, Borneo, on 15 November that same year.