In successive summers from 1925 to 1928, the cargo vessel operated between Seattle, Washington, and Alaskan ports, carrying supplies and stores to naval radio stations at St. Paul and Dutch Harbor. In addition, "Vega" and sister ship carried general freight, heavy guns, and ordnance parts in support of Marine peacekeeping activities in Nicaragua. Among "Vega's" cruises were voyages in 1928 carrying supplies for the Bureau of Fisheries, Commerce Department, to seal rookeries on Pribilof and other Alaskan islands. She returned with seal skins garnered during supervised killings.