ARA Alférez Sobral (A-9) is an 800-ton ocean-going tug that was in service with the Argentine Navy from 1972 until 2019, where she was classified as an aviso. She had previously served in the US Navy as the fleet tug USS Salish (ATA-187). In Argentine service an aviso is a small naval vessel used for a number of auxiliary tasks, including tugging, laying buoys, and replenishing other ships, lighthouses and naval bases.