The tug's long service in the Pacific Northwest, including a role in the Klondike Gold Rush, was interrupted by preparations for war in early 1941. After delivering a drydock gate to Pearl Harbor the tug was chartered by Contractors Pacific Naval Air Bases, a consortium formed to build air fields on remote Pacific islands as the United States prepared for war. In June 1941 "Arthur Foss" was supporting construction on Wake Island and was there in November along with the smaller "Justine Foss" transporting construction materials from barges in the lagoon to the island. When the work was completed the tug was scheduled to return to Hawaii with two barges in tow.