Jack and Charmian sailed from Hawaii to San Francisco July 1916, on the SS Sonoma a 6279 ton passenger liner built by William Cramp & Sons in Philadelphia in 1900. It operated for the Oceanic Steamship Company, travelling between San Francisco and Sydney making stops at Honolulu and Auckland. The vessel was scrapped in 1934.
Oceanic Steamship Company was founded in 1881 by John D. Spreckels & Brothers and ran services from the USA, initially to Hawaii, later to Australia and New Zealand. In 1926 Oceanic sold out to Matson Line and became a subsidiary company.