Australia’s longest-running naval mystery – the disappearance of the nation’s first submarine – has been solved after 103 years.

The fate of HMAS AE1 had been one of the navy’s most enduring puzzles, sparking 13 different retrieval attempts since 1914, when the vessel vanished without a distress call off the coast of Papua New Guinea during the first world war.

According to naval historians, ships could find “no trace” of AE1, not even “the tell-tale shimmer of escaping oil on the water”.

But on Thursday the defence minister, Marise Payne, announced the submarine had been found.

The 800-tonne vessel was discovered under 300 metres of water near Duke of York Island in Papua New Guinea. A commemorative service was held in memory of the 35 Australian and British crew who died on board, and Payne said the government had entered discussions with the PNG government to establish a lasting commemoration of the site.

AE1 was the first Allied submarine lost in the first world war and the first ship lost by the Royal Australian Navy.

The submarine, in operation for only seven months, had been sent from Sydney to capture what was then German New Guinea in 1914. On 14 September, a day after Germany surrendered the colony, it disappeared.

The rear of HMAS AE1s fin broken away from its footings. Photograph: Fugro Survey/AAP

It was “a tragedy for our then fledgling nation”, Payne said. “This is one of the most significant discoveries in Australia’s naval maritime history.”

The chief of navy, Vice Admiral Tim Barrett, added: “We were a young navy at the time.”

Payne and navy officials said the cause of the submarine’s loss would now be investigated. Retired rear admiral Peter Briggs, who worked on the search, told the Australian that he believed the cause was most likely “a diving accident”.



“The submarine appears to have struck the bottom with sufficient force to dislodge the fin from its footing, forcing it to hinge forward on its leading edge, impacting the casing,” he said.

The successful search, which began on Sunday, was funded by the government and the Silentworld Foundation. It was assisted by the Submarine Institute of Australia, the Australian National Maritime Museum, company Fugro Survey, the PNG government and the group Find AE1 – which is led by Briggs.



The area in which AE1 disappeared was notoriously difficult to search. In 2014, navy sources described it as “one of the most wreck-strewn areas in the region”.

Payne said the government had begun attempts to contact descendants of the crew. “I truly believe this will bring peace of mind to the family and descendants of the crew who lost their lives onboard,” she said. “Perhaps, in time, we may discover what caused the submarine to sink.”