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NavSource Online:
Patrol Yacht Photo Archive

Ruby (PY 21)

Call sign:
Nan - Baker - George - Mike

Patrol Yacht:

  • Built in 1930 as the yacht Placida by Bath Iron Work, Inc., Bath, Maine
  • Purchased by the Navy 19 June 1941
  • Renamed Ruby and designated as a Patrol Yacht PY-21, 6 July 1941
  • Commissioned 23 September 1941 at Jacksonville, FL
  • Decommissioned 25 July 1945 at Boston, MA
  • Struck from the Naval Register 13 August 1945
  • Transferred 26 December 1945 to the Maritime Commission for disposal
  • Fate unknown.


  • Displacement 640 t.
  • Length 190' 11"
  • Beam 26' 6"
  • Draft 10' 6"
  • Speed 13.5 kts.
  • Complement 67
  • Armament: One 3"/50 dual purpose gun mount and four 1.1"/75 caliber anti-aircraft guns
  • Propulsion: Two 1,600bhp Cooper Bessemer JR-8 diesel engines, two shafts.
    Click on thumbnail
    for full size image
    Size Image Description Source
    Motor Yacht Placida
    Ruby 136k
    USS Ruby (PY 21)
    Ruby 26k

    A ruby is a pink to blood-red colored gemstone, a variety of the mineral corundum (aluminum oxide). Other varieties of gem-quality corundum are called sapphires. Ruby is one of the traditional cardinal gems, together with amethyst, sapphire, emerald, and diamond. The word ruby comes from ruber, Latin for red. The color of a ruby is due to the element chromium

    Tommy Trampp
    Ruby 110k
    Ruby 290k 19 November 1942
    Charleston Navy Yard, Charleston, SC
    In Dry Dock No. 2. Moored behind Ruby is YMS-37 along with Army dredge Col. G. P. Powell (not Howell), Army QTR No. 2, Army barges No. 7, 17 and 4, YC-579,
    and YP-429
    U.S. Navy photo 1756-42
    Robert Hall
    Ruby 141k Original photo: 8 March 1943
    Replacement photo: 8 March 1943
    Photographed by the Charleston, South Carolina Navy Yard, probably after repairs
    National Archives photo 19-N-42296
    Naval History and Heritage Command
    Replacement photo added 14 February 2021

    View the Ruby (PY 21)
    DANFS History entry located on the Naval History and Heritage Command Website
    Back to The Main Photo Index Back to the Patrol Craft/Gunboat/Submarine Chaser Index Back to the Patrol Yacht (PY) Photo Index

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    This page created by Gary P. Priolo and maintained by Joe Radigan
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