The Portuguese Navy said the Roberto Ivens minesweeper sank in 1917 after striking a mine released by a German submarine.
“In the year that we commemorate the centennial of Portugal entering the First Great War, the detection and retrieval of information from this ship gains added historical significance”, the Portuguese Navy said in a statement.
The Navy added that the wreckage of the war ship was detected on Monday through the use of lateral sonar, and was located about four nautical miles south of the entry to the Lisbon port.
The Navy explained that it would now use a ROV (Remotely Operated Vehicle) in order to capture images from the depths of the ocean and to fully ascertain the condition of the wreckage for possible retrieval at a later stage.