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Section Patrol Craft Photo Archive

USAT S. D. Mason (FS 551)
ex-USLHS Fern
ex-USS Fern (SP 635)
ex-USLHS Fern

Fern served the U. S. Lighthouse Service, the U.S. Navy and the U.S. Army

Lighthouse Tender:

  • The third Fern built in 1915 by Hall Brothers Shipbuilding Co., Winslow, WA for the Light House Service
  • Commissioned USLHS Fern 25 June 1915 and based at Ketchikan, AK
  • Acquired by the Navy 4 September 1917 and placed in service the same day
  • Returned to the Light House Service by Executive Order dated 1 July 1919
  • Acquired by the Army 19 September 1934 and renamed USAT S. D. Mason (FS 551)
  • Sold after World War II and put into service as a freight boat based at Seward, AK
  • Fate unknown.


  • Displacement 317 t.
    1917 - 237 t.
  • Length 112'
    1917 - 98' 5"
  • Beam 22'
  • Draft 10'
    1917 - 8' 6"
  • Complement 12
    1917 - 15
  • Armament: None
    1917 - Two 3-pounders
  • Propulsion: One water tube, oil fired Almy-type boiler; one triple-expansion vertical inverted steam engine; one shaft
    1934 - One 300hp diesel engine.

    Click on thumbnail
    for full size image
    Size Image Description Source
    Fern 210k USAT S. D. Mason (FS-551), tied up pierside, probably at Seattle, WA
    U.S. Army Corps of Engineers, Seattle District photo
    Photo from "U.S. Army Ships and Watercraft of World War II" by David H. Grover
    Robert Hurst

    View the Fern (SP 635)
    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 Ship Index Back to the Section Patrol Craft (SP) Photo Index

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