HMAS Onslow was gifted to the Australian National Maritime Museum in Darling Harbour, Sydney, in 1999, just weeks after being de-commissioned. Today, as one of the museum’s most popular “living” exhibits, the Oberon Class submarine remains in near operational condition.

Every year throngs of visitors hear about and view – among Onslow’s many other features – a diving chamber used by Special Forces to leave the boat for covert operations (a facility unique to Onslow), a gash or rubbish bag ejector containing weighted refuse sacks that sank to the ocean floor leaving no tell-tale signs of the submarine’s presence, and the extraordinary soundproofing on all equipment that made Oberons one of the quietest submarines ever built.

She roamed the seas at the height of the Cold War, a tense period in international affairs that called for a submarine to watch, listen and collect information, all without detection. Her actual operations remain highly classified however, the ANMM website suggests her most secretive work may have included tracking Soviet submarines moving into the Indian Ocean and Arabian Gulf from Vladivostok via the Coral Sea and the Great Australian Bight.

What is clear is that with the five other Oberons, Onslow gave the Royal Australian Navy a formidable submarine force.

Onslow travelled the equivalent of more than 16 times around the world, serving Australia with “silent” distinction for 30 years.

HMAS Onslow sports a unique ship’s badge; a judge’s wig and a bunch of roses. It is in recognition of the submarine’s namesake, Sir Alexander Onslow, the third Chief Justice of Western Australia who required a fresh bunch of flowers at each sitting of the court so that he need not smell the accused person before him. Onslow also shares its motto, Festina Lente – Latin for “Hasten Slowly” – with the Onslow family.

In 1981 an incident occurred off the NSW coast during dived operations when shutting down the diesel engines and Carbon monoxide and exhaust fumes vented into the submarine and filled the Onslow with toxic gases. Many of the crew were badly affected and tragically one sailor died.

14 years later ONSLOW was the subject of critical review and criticism following a controversial “ceremony” in 1995 reported to undertaken in order to “induct” new sailors. The junior submariners were verbally and physically abused, had parts of their bodies covered in a “blistering concoction”, and were thrown overboard. There was a public outcry following airing of videotape of the hazing. An enquiry resulted in appropriate restrictions being implemented aboard RAN vessels.

Onslow served with distinction. She became the first conventionally powered submarine to be fitted with anti-ship missiles and was highly successful in wargames; “sinking” a seven-ship flotilla during Exercise Kangaroo 3 in 1980 and the super-carrier USS Carl Vinson at RIMPAC 1998.