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Section Patrol Craft Photo Archive

ex-Alert (SP 511)

Civilian call sign (1919):
Love - Dog - Cast - Nan


  • Built in 1913 by George Lawley and Sons, Neponset, MA
  • Acquired by the Navy 12 May 1917
  • Commissioned Alert (SP 511), 31 May 1917
  • Renamed SP-511 in April 1918
  • Decommissioned 30 November 1918, struck from the Navy Register and returned to her owner
  • Fate unknown.


  • Displacement 39 t.
  • Length 75'
  • Beam 12'
  • Draft 3' 9"
  • Speed 15.6 kts.
  • Complement 11
  • Armament: One 1-pounder
  • Propulsion: Two 150hp 6-cylinder Speedway gasoline engines, two shafts.
    Click on thumbnail
    for full size image
    Size Image Description Source
    Alert 121k Photographed prior to World War I by Edwin Levick, New York City
    U.S. Navy photo NH 100105
    Naval Historical Center
    USS Alert SP 511)
    Alert 79k Jay Milewski
    Alert 229k Lockwood's Basin, Boston, Massachusetts. View of the basin with a seaplane from Chatham flying overhead, circa 1918.
    Taken by Alton M. Blackinton, Boston.
    USS Moosehead (ID 2047) is at the right, with several patrol vessels nearby. USS Elsie III (SP-708) is in the left foreground, with USS SP-511 (ex-Alert) beyond her
    U.S. Navy photo NH 42146
    Naval Historical Center

    Dictionary of American Naval Fighting Ships: The motorboat Alert built in Neponset, Mass., by George Lawley and Sons, in 1913ówas acquired by the Navy under free-lease on 12 May 1917 from DeWitt T. Cuyler, of Philadelphia Pa., for use as a section patrol boat. Designated SP-511, Alert was commissioned on 31 May 1917.

    Assigned to the 1st Naval District, Alert performed local patrol duty at the Portsmouth (N.H.) Navy Yard and in the Boston area for the remainder of World War I. Decommissioned at Lawley's shipyard on 25 November 1918, two weeks after the signing of the armistice, the boat was returned to her owner on 30 November 1918.

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