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NavSource Online: Mine Warfare Vessel Photo Archive

HM BYMS-2026
ex-HM J-826

BYMS-26 was built for Great Britain

BYMS-1 Class Motor Minesweeper:

  • Laid down 12 August 1941 as BYMS-26 by Ballard Marine Railway Co., Inc., Seattle, WA
  • Launched 21 March 1942
  • Sponsored by Isobel Prentice, the daughter of the Ballard Marine Railways foreman
  • Completed and transferred to Great Britain 22 August 1942
  • Commissioned HM J-826 in February 1943
  • Renamed HM BYMS-2026 in 1944
  • Decommissioned in 1946 and laid up at Malta
  • Struck from the Navy Register 10 June 1947 and transferred to the State Department, Foreign Liquidation Commission
  • Returned to U.S. custody 1 August 1947
  • Sold to Joseph Gasan, converted to a car ferry and named Calypso
  • Operated between Malta and Gozo
  • Sold to Thomas Loel Guinness and leased to Jacques Cousteau for one Franc per year
  • Struck by a barge 8 January 1996 and sank at Singapore
  • Salvaged 25 January 1996 and towed to Marseille, France
  • Presently at LaRochelle, France awaiting her fate.


  • Displacement 270 t.
  • Length 136'
  • Beam 24' 6"
  • Draft 8'
  • Speed 15 kts.
  • Complement 32
  • Armament: One 3"/50 dual purpose gun mount, two 20mm mounts and two depth charge projectors
  • Propulsion: Two 800bhp General Motors 8-268A diesel engines, Snow and Knobstedt single reduction gear, two shafts.
    Click on thumbnail
    for full size image
    Size Image Description Source
    HM BYMS-2026
    BYM-9 316k Grand Canal, Venice, Italy
    Moored inboard of BYMS-2009 after all the mines had been cleared
    From the collection of Victor Gatherum
    Tim Gatherum
    RV Calypso
    BYMS-2026 271k 30 August 1980
    Arriving at Montreal, Québec, Canada
    Photo by René Beauchamp via courtesy of Robert Hurst
    BYMS-2026 233k RV Calypso during a visit to St. Paul, MN., on the Mississippi River, 1983. Photo by Steve Moses via courtesy of Erik Tylczak
    BYMS-2026 174k c. April 1997
    RV Calypso in Marseille, France at the Calypso alumni meeting. Personnel shown are 2nd from left Claude Wesly, 3rd from left Philippe Tailliez and 4th from left
    Albert Falco
    Photo by Maisrimer
    Robert Hurst
    BYMS-2026 78k c. April 1999
    La Rochelle, France
    Photos by Peter Potrowl
    Robert Hurst
    BYMS-2026 78k c. April 1999
    La Rochelle, France
    Photos by Peter Potrowl
    Robert Hurst
    BYMS-2026 274k 9 November 2007
    Calypso on the stocks at the Piriou Shipyard, Concarneau, Brittany, France, while undergoing restoration and transformation into a permanent exhibit
    Photo courtesy of Olivier Bernard
    Robert Hurst
    NR Diagram of the RV Calypso inspired by Erik Tylczak. Photo courtesy of

    There is no DANFS history available for BYMS-2026
    Back to the Main Photo Index Back to the Mine Warfare Ship Photo Index Back to the British Motor Minesweeper (BYMS) Photo Index

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