The 66-year search for the wreck of HMAS Sydney, on which 645 Australians lost their lives, is almost certainly over.
A group of West Australians using just a grappling hook and an underwater camera last weekend found what they are sure is the Sydney, which sank after a battle with the German raider Kormoran on November 19, 1941.
Their video film shows scenes of tangled wreckage over a vast expanse of deck, much longer than any other vessel known to have sunk in the area.
The search team believe a series of details clearly visible on their video - decking bolts, extensive radio aerials, steam tubes and signs of massive damage - all point to the Sydney. The wreck is off Cape Inscription on the northern end of Dirk Hartog Island in about 150 metres of water.
Phil Shepherd, an amateur researcher who has been intrigued by the Sydney's fate for 61 years, since he saw a lifeboat from the Kormoran (which also sank in the battle), said last night it was unlikely the wreck could be anything else.
"I've always wanted to find out where the souls of those sailors lay for all the people who have grieved over the years," Mr Shepherd said. "I've got a family member there too.
"This is a sacred site and a war grave - probably our most important war grave. We hope we can give the families some closure knowing where their people are and where they can place some flowers."
Mr Shepherd, who has been involved in other groups searching for the Sydney, said that despite the rudimentary nature of the video, it provided strong evidence supporting his contention.
"Sydney had a huge aerial system for its wireless telegraphy, and we think we're seeing that on the video," he said.
"There are bolts sticking out of the deck, lots of steam pipes and tangled wreckage. The bolts are important because we know the Sydney had timber decking that was tied down by the bolts.
"You would not expect that sort of damage from anything that had just sunk. It is inconsistent with it being anything else, like a merchant ship.
"I knew the Sydney was flattened by the Kormoran by gunfire. She caught fire because of the wooden decking. We believe she took a torpedo and was down by the bow and yawing.
"I became more convinced when I saw all these halyards and what looked like aerial wires with insulators strewn over the debris, over railings. It looked like the mast had been shot down. All of this convinced me it wasn't an ordinary vessel.
"It didn't prove to me that it was a military vessel, but I asked myself: What else could it be if it's not the Sydney? The only other vessel it could be in that location is the Kormoran. If it was any other vessel than the Sydney or the Kormoran in that location, why hadn't it been reported as missing and looked at?"
Later he showed the video to another team member, diver Trevor Beaver, who had explored US naval wrecks in Truk Lagoon in the Pacific. "He took one look at the video and he said, 'You've got it. It couldn't be anything else.' "
Mr Shepherd said that about 15 years ago he noticed an anomaly on the seabed when he was fishing. But it was before the days of global positioning systems and he did not know how to get back to the spot.
Early this year he was given a location close to that spot by the son of a local fisherman, who had pulled up a copper bolt with a little bit of white timber attached to it about 12 years ago.
"From all of my research, with this new information, it became logically possible that this was the location," Mr Shepherd said.
He began working with his son, Graham, master divers Ian Stiles and Trevor Beaver, Perth businessman Terry Crommelin and diving supplies agent Simon van Zeller to work out a way to investigate the site. They devised a method of getting a camera down to film it. Last weekend the late fisherman's son agreed to take them to the spot.
"We put down a heavy grapple and we were on the spot nearly straight away and hooked up on something," Mr Shepherd said. "We put the camera down on a tether rope ... When we got to the bottom we got pictures, and within three minutes we spotted what looked like a spoon - which we now believe was a shovel - just lying in the sand.
"Then this shape of what we thought was part of an aerial - now we think it's a railing - just came up out of the gloom.
"We were absolutely gobsmacked. And it just got better and better."
Mr Stiles took GPS locations as the camera travelled along the deck of the wreck to the extent of available movement. He logged a length of 30 metres. The Sydney was about 170 metres long.