On December 20, the team discovered the long lost AE1.

AE1 and AE2 were Royal Australian Navy’s first two submarines, commissioned in 1914.

AE1 was last seen at around 3:20pm on September 14, 1914, near the Duke of York Islands. It was part of the fleet involved in seizing a communications station in what was then German New Guinea.

It never returned to base at Rabaul that night.

An initial search was mounted, but no trace of the vessel was found.

The AE2 played a critical part in preventing the build up of Turkish forces at Gallipoli. It was sunk in April 1915, with no loss of life. In 1998, it was located in the sea of Marmara.

The loss of the two vessels marked the end of Australia’s submarine force until the early 1960s.

Commodore Roach was one of the first young officers sent to the United Kingdom to train. Following that he was CO of the HMAS Otway, then the HMAS Ovens. He ended his career as a naval attaché in Washington before retiring to Braidwood.

The search was sparked by the enthusiasm of Commander John Foster in the 1970s. It gained momentum as Commodore Roach’s generation of submariners reached retirement age.

However, not until recently was the technology available to mount a proper search for the vessel.

The team found the AE1 on the seabed near the Duke of York Islands, close to where it was last sighted.

It may never be known for certain why the vessel was lost, but it appears likely it took on water and sunk below its crushing depth before hitting the sea bed.

For Commodore Roach, finding the vessel’s remains is an importance act of remembrance for those who lost their lives.

It’s the same reason we celebrate Anzac Day, he says.

“It’s to commemorate the people who’ve sacrificed their lives on behalf of the nation,” Commodore Roach said. “The difference is, with Anzac Day there are lots of crosses in the ground, here, empty ocean.”