 On 6 April 1917 the United States declared war on the "Imperial German Government" and the Coast Guard was placed under the jurisdiction of the U.S. Navy for the duration of the war by executive order signed by President Woodrow Wilson.Duties for "Unalga" did not change under Navy control initially and she left for her usual summer patrol work in Alaskan waters on 4 May.At the end of the summer cruise, she was assigned submarine tender duties with the Twelfth Naval District and home-ported at San Pedro, California, arriving 17 October.