Lady Fern – Athyrium filix-femina

HMS Thorough was a British submarine of the third group of the T class. She was built as P324 by Vickers Armstrong, Barrow, and launched on 30 October 1943. So far she has been the only ship of the Royal Navy to bear the name Thorough.

Thorough served in the Far East for much of her wartime career, where she sank twenty seven Japanese sailing vessels, seven coasters, a small Japanese vessel, a Japanese barge, a small Japanese gunboat, a Japanese trawler, and the Malaysian sailing vessel Palange. In August 1945, in company with HMS Taciturn, she attacked Japanese shipping and shore targets off northern Bali. Thorough sank a Japanese coaster and a sailing vessel with gunfire.

On 16 December 1957 Thorough returned to HMS Dolphin, Portsmouth Dockyard, after completing the first circumnavigation by a submarine.^[1] While in Australian waters, on 2 August 1956, she rescued one of the four survivors of the sinking of the 'sixty-miler', Birchgrove Park.^[2][3]

She survived the war and continued in service with the Navy, finally being scrapped at Dunston on Tyne on 29 June 1962.^[4]

• Colledge, J. J.; Warlow, Ben (2006) [1969]. Ships of the Royal Navy: The Complete Record of all Fighting Ships of the Royal Navy (Rev. ed.). London: Chatham Publishing. ISBN 978-1-86176-281-8.
• Hutchinson, Robert (2001). Jane's Submarines: War Beneath the Waves from 1776 to the Present Day. London: HarperCollins. ISBN 978-0-00-710558-8. OCLC 53783010.