Submarines

Association

Australia

Vale

Crest

In Memory of

VALE COMMANDER LEONARD JAMES (JIM) DENNIS, RAN (RTD) – R49400/ O1666

The Submarines Association of Australia is saddened to advise of the passing of member Jim Dennis on Tuesday morning the 18th August 2026 after a brief illness at the age of 90.
Jim Dennis was born in Toowoomba, Queensland, on 11 October 1935, the third of six children of John and Esther Maud Dennis.

He enlisted in the Royal Australian Navy for six years on 10 April 1953 and commenced training at HMAS Cerberus. Rated as an Electrical Mechanic 2nd Class on 10 October 1953, he completed his category training on 1 May 1954 and was posted to HMAS Barcoo, a World War II– vintage River-class frigate that had been converted into a hydrographic survey ship. Over the next seventeen months, Jim served aboard Barcoo as she surveyed the Great Barrier Reef, the coasts of northern New South Wales and Queensland, and areas of South Australia.

In October 1955, he returned to Cerberus for advanced electrical training. Upon completion, he was advanced to Acting Leading Electrical Mechanic in August 1956 and posted to the light aircraft carrier HMAS Sydney. He was confirmed in rank twelve months later. When Jim joined the ship, it had a large contingent of Navy National Servicemen and several classes of Permanent Navy trainees onboard increasing the overall workload on the crew. The day he joined Sydney also marked the first occasion that Jim sailed for an overseas port – Suva in Fiji. Over the next twelve months he would enjoy the delights of Singapore, Thailand, Hong Kong, and the Philippines, as well as visiting numerous Australian ports.

Jim’s ability evidently impressed his superiors, for in 1957 he was selected as an “Upper Yardman” officer candidate and posted to the United Kingdom. At a time when most RAN personnel travelled by sea, Jim flew in a De Havilland Comet—Britain’s first jet passenger aircraft. He was discharged from the RAN as a sailor on 31 December 1957 upon being appointed an Acting Sub-Lieutenant (L) RAN.

He completed his officer training at the Royal Naval College, Greenwich, before undertaking gunnery and electrical engineering courses at HMS Excellent and HMS Collingwood. He then completed the sea phase of his officer training with the RN. He was awarded his Engineering Certificate of Competency in July 1959 and he was promoted to Lieutenant in 1960. Jim returned to Australia to join the Daring Class Destroyer HMAS Vampire in February 1961. He would serve on her until August 1963, during which time the destroyer deployed to the Far East. 1962 would be a milestone year for Jim Dennis, it was during that year he would marry Susan Elizabeth Cramond – the couple would be married for 62 years until Sue’s death in 2025. It was also in 1963 that the Australian Government would announce the acquisition of three (later six) Oberon-class submarines and called for volunteers to man them. Jim was among the first technical officers to step forward, and in September 1963 he returned to the UK for submarine training at HMS Dolphin in Gosport. During his course, he took part in a training cruise aboard HMS Odin and then joined HMS Opportune, then under construction at Scotts Shipbuilding in Greenock. A near-sister to the Australian Oberon class, Opportune gave Jim invaluable experience—he remained with her until January 1966, when he returned to Scotts to stand by HMAS Oxley, which had been laid down only weeks before his earlier arrival in the dockyard. While on Opportune, he also completed a special operations patrol (a “Mystery Trip”) in May–June 1965.

Jim was appointed HMAS Oxley’s commissioning Weapons Electrical Engineering Officer (WEEO). Oxley commissioned on 21 March 1967 and, after work-ups, sailed for Sydney via Bermuda, Jamaica, Panama, Pearl Harbor, and Brisbane. Her arrival was timed to coincide with the commissioning of HMAS Platypus on 18 August 1967. On 1 October 1967, Jim was promoted to Lieutenant Commander, and the following year he was posted to the Directorate of Submarine Maintenance and Repair at Navy Office.

On 31 December 1971, he was promoted to Commander—the first home-grown RAN submarine technical officer of his era to reach that rank. Two weeks later, he joined the troop transport HMAS Sydney as her Commander Engineering. It was a remarkable homecoming: from his first posting to the ship sixteen years earlier as an Acting Leading Electrical Mechanic, he now became her last Commander Engineer. In that role, he participated in Sydney’s final two deployments to Vietnam in 1972, bringing troops and equipment back to Australia.

When Sydney decommissioned in November 1973, Jim moved to the RAN’s Missile and Torpedo Maintenance Establishment in Western Sydney.
In September 1978, he returned to submarines as the Submarine Squadron’s Senior Principal Technical Officer—a position in which he was widely respected—and he remained there until his retirement from the RAN in December 1980.

Jim and Susan lived in Chatswood West NSW from 1992. He joined the Submarines Association of Australia in 2009 and he was an active member of the NSW branch, regularly attending meetings until as late as last year. He was predeceased by Sue in June 2025. At the time of his death Jim was one of the oldest home grown Australian submariners in the Association.

Jim’s funeral will be held at the Palm Chapel at Macquarie Park Cemetery and Crematorium, Macquarie Park NSW at 1115-1215 on Friday 28th of August 2026. It is requested that those attending, RSVP via the following link.Vale Jim Dennis

The SAA extends its heartfelt condolences to Jim’s daughters Amanda, Kate and Rebecca and their extended families and friends.