HMS Onyx (S21)

HMS Onyx was an Oberon class submarine of the Royal Navy. Originally ordered for the Royal Canadian Navy, Onyx was transferred to the Royal Navy whilst under construction at Cammell Laird shipbuilders in Birkenhead, England. She was launched on August 1966 and commissioned into the Royal Navy in September 1967.

The first commission of the Onyx saw her visit Swansea in South Wales for the investiture of His Royal Highness The Prince of Wales. She also attended the bicentennial celebrations of the United States of America in 1976.

The submarine's motto, "Taurus excreta cerebrum vincit," is correctly translated as "Bullshit conquers brains".

Falklands War
HMS Onyx was the only non-nuclear submarine of the Royal Navy to take part in the Falklands War. The smaller displacement of Onyx compared to the nuclear submarines made her ideal for landing SAS and SBS troops close to the islands in shallow waters. During one of these missions, Onyx ran aground and suffered minor damage to its bow. After British officers scrapped Operation Mikado, the replacement plan consisted of Onyx dropping SAS operatives several miles offshore at night for them to make their way to the coast aboard rubber inflatables in order to destroy Argentina's remaining stockpile of Exocet missiles.

HMS Onyx sank the hulk of the landing ship Sir Galahad after she was badly damaged at Bluff Cove.

Decommissioning and preservation
Defence cuts in the UK saw the Royal Navy dispense with its diesel-powered submarines to concentrate on nuclear attack submarines. In 1991, the Onyx was decommissioned from the navy. She was then cared for by the Warship Preservation Trust and was on public display alongside several other ships in Birkenhead, UK.

In May 2006 HMS Onyx was sold to the Barrow-in-Furness businessman Joe Mullen, for a reported £100,000 as a 'gift to the people of Barrow'. She left Birkenhead on 13 June 2006 to form the centrepiece of The Submarine Heritage Centre, a new heritage museum in Barrow-in-Furness, Cumbria, as a celebration to the town's illustrious Submarine-building history.