The fate of one is a mystery, the other altogether revealed: The stories of World War I submarines AE1 and AE2

A SMALL pebble collected from the outside of a stone house in Eaglehawk will take on special significance at a World War I service in Papua New Guinea next Sunday.

The service is to commemorate 100 years since the disappearance of Australia's AE1 submarine near Rabaul on September 14, 1914.

The Eaglehawk pebble represents John (Jack) James Bray, one of the submarine's 35 lost crew members and the first man from Bendigo to die in WWI.

Bendigo resident Faye Frewin - Jack's sister's grand-daughter - collected the pebble after being approached by Vera Ryan, a member of the AE1 descendant's organisation.

The 35 descendent families in Australia were asked to post a little stone or pebble from the city where their lost ancestor came from, Faye said.

"I was able to go out to Clark Street in Harveytown in Eaglehawk and collect a little pebble from outside the stone house," she said.

Faye said the home, which still stands, was built by Jack's grandfather, a Cornish miner.

"I picked up the pebble and posted it to Vera and got some correspondence back that was very excited - it was the first pebble that she had received," she said.

Vera's idea was based on a Jewish custom that when visiting a grave, you took a pebble and left it there.

The symbolism is important given the mystery surrounding the AE1's disappearance has meant generations later, descendants such as Faye and her family still have many unanswered questions.

"There are so many possibilities (about what happened) - the Germans might have shot it, it might have been rammed by the boat that was supposed to be escorting it, the boat that was supposed to be with it but detoured off looking for Germans," Faye said.

Faye says the news about the AE1 shocked the family and the community in 1914.

"It had a bad affect on his mum, Alice Bray, because she became very unwell after it," she said.

While Jack had trained as a blacksmith at the School of Mines in Bendigo, he was one of the first Australians to enlist in the Royal Australian Navy, Faye said.

"In the middle of the year when he enlisted, 1912, was just after the navy had been formed. So he was one of the first ever recruits," she said.

"The Brays were such a proud Eaglehawk family and there was such a big fuss made in the Bendigo Advertiser... about Jack being the first local."

Faye said the reaction on a local level mirrored widespread grief across the country.

"It was Australia's first war tragedy. It was the first big tragedy, a big loss for Australia," she said.

Faye's grandmother, Jack's sister, inspired a family interest in the AE1 mystery which was passed down to Faye and her brother, Ian McKenzie.

"Ma always wondered what happened to Uncle Jack, she often talked about him and what a great mystery it was," Faye said.

Fortunately, she was also a "great hoarder" of some of Jack's returned possessions, Faye said.

"She kept absolutely everything, and Ian's got some fantastic bits and pieces she saved, " she said.

In the 1970s, Ian wrote to the then Navy Commander, John Foster, who began investigating the disappearance and called for new searches to find the AE1.

Faye said her own and others' research into the mystery left her open to hope for the AE1's eventual location.

In stark contrast to the fate of the AE1 and its crew, its sister WWI submarine the AE2 continues to reveal its secrets.

The AE2 sank off the coast of Turkey on April 30, 1915, after being shot three times, but all of its crew survived.

As part of a $3.7 million operation funded for the 2014 WWI centenary, a group of Australian scientists and Turkish divers set out on a mission earlier this year to conduct a detailed survey of the AE2's interior.

One of the scientists, Macedon resident Dr Roger Neill, spoke to a small forum about the successful mission at Bendigo RSL in early August.

Dr Neill was part of a preliminary mission to Turkey to inspect the AE2 in 2007 and said the 2014 revisit followed talks between the Australian and Turkish governments about how to protect and conserve the wreck and tell its story.

Dr Neill said the AE2 was dubbed the 'Silent Anzac' because it was the first submarine to break into the Dardanelles during the Gallipoli campaign in 1915.

"We wanted to tell its story because Gallipoli is not just about Normandy and the beaches, there's more to that story, this is part of that story, an important part," he said.

"It's the largest remaining single intact artefact of the Gallipoli campaign at 700 tonnes."

He said one of the major aims of the 2014 mission, along with preserving the wreck, was to visualise the inside of the submarine with a better camera. 

Getting inside the wreck proved a huge challenge for the team.

"The first thing that happened was that we didn’t know it was a cast brass hatch... our 2014 camera was about 1mm too big... in the end we needed a Turkish support diver to help manoeuvre the camera," Dr Neill said.

Then, having pried open the hatch, the vehicle carrying the camera and scientific measurement equipment got stuck while being lowered in.

“A $150,000 piece of equipment got solidly jammed in the lower hull, seven metres down," Dr Neill said.

"A smaller vehicle, less modern, had to be modified over a 24-hour period to fit our little vehicle through the hole."

Once inside, the vehicle spent three days exploring the inside of the wreck and Dr Neill said it soon became apparent all the setbacks had been worth it.

"Sitting on the desk in the officer’s ward room, on the desk, was a crystal decanter," he said.

"How that crystal decanter managed to survive the sub going down I'll never know.

"Sitting above that desk was a little bit of English luxury, an oyster light fitting.

"And the globe was intact, it hadn’t fractured. In fact, we didn't find one broken light in the whole boat."