The third USS Alert was an iron-hulled screw steamer gunboat in the United States Navy. The lead ship in her class, Alert was destined for a long naval career, serving from 1875 to 1922, a period of 47 years, including service as a submarine tender in World War I. Toward the end of her career she received the designation AS-4. Alert was laid down in 1873 by John Roach & Sons at the Delaware River Iron Ship Building and Engine Works shipyard, Chester, Pennsylvania in 1873. Launched on 18 September 1874, Alert was commissioned for the first time on 27 May 1875, Commander William T. Sampson in command. Service history First commission, 1875–82 Training ship The screw steamer spent the first year of her Navy career attached to the North Atlantic Station. During the summer, she wore the flag of Rear Admiral C. R. Perry Rodgers, Superintendent of the Naval Academy, and hosted cadet-midshipmen on board for practical training in the operation of steam propulsion equipment – all as a part of the Academy's practice cruise for 1875. Atlantic and Asiatic stations Alert operated out of ports on the Atlantic coast during the fall and winter of 1875 and 1876 until departing New York on 26 May 1876 on the first leg of a voyage to the Asiatic Station. Proceeding by way of the Mediterranean Sea and the relatively new Suez Canal, she stopped at Gibraltar, Malta, and Aden before reaching Hong Kong on 11 September. For almost three years, the ship cruised the waters around Japan and along the Chinese coast, showing the flag at such places as Yokohama, Nagasaki, Kobe, and Hakodate in Japan, and Hong Kong, Shanghai, Amoy, and Swatow in China. Unlike modern goodwill visits, her port calls frequently could be measured in terms of weeks and months rather than days. When at sea, she charted hydrographic features, investigated maritime disasters, and performed humanitarian services for the victims of those disasters. On 4 January 1879, Alert departed Yokohama on her way back to the United States. She arrived at the Mare Island Navy Yard on 24 February and began a six-month repair period. On 30 August 1879, the warship set sail from San Francisco on her way back to the Asiatic Station. The steamer arrived in Yokohama on 6 October and commenced 32 months of service in the Far East. In addition to the normal port