 She was converted to a submarine tender at the Mare Island Navy Yard and was commissioned there on 1 October 1918, Lieutenant Commander James A. Logan in command.To prepare her to serve as mobile repair and maintenance facility for submarine squadrons, the yard workers installed a machine shop, electrical plant, battery shop, and refrigerator units inside the ship.Since her duties included providing boat services to submarines, the tender carried four motor launches, three motor boats, and five smaller craft.