At his home on the remote island of Milingimbi, off the coast of north-east Arnhem Land, ranger John Skuja keeps a pointed reminder of the dangers of working at sea.
"We've got a piece of wood, vaguely curved and about 70 centimetres long, that looks like part of a boat hull from some unknown disaster," he says.
"Who knows how many lives have been lost from the boat, [which] broke up and sunk somewhere north of Australia, and then floated down."
John, who has lived in the remote community for eight years, is the manager of the Crocodile Island Rangers — a conservation group tasked with looking after Yolngu land, including its wetlands, river systems and sea country.
So when a group of Yolngu fishers spotted a very large, mysterious object floating near the northernmost point of the nearby Murrungga Island last weekend, John was the person they called to investigate.
"When we first went out it was a very, very rough day … from a fair way away, we could see an unusual sort of shape," he says.
"As we got closer we could see it was an upturned vessel."
According to eyewitnesses, the boat measured about 25 metres long, with a hull constructed out of fibre-glass and wood, now covered in white bird poo and algae.
A huge wad of ghost net — a term referring to abandoned or lost fishing gear — was tangled in the propeller.
"It's hard to say whether that's happened after the boat has capsized … or possibly that was a contributing factor to it coming unstuck," John says.
It's not uncommon for debris and rubbish to wash up on the pristine beaches of Arnhem Land, but the sheer size of the object presented an issue for Yolngu communities nearby.
"There was a bit of concern because it is nearby a sacred site. Interestingly, when we were first aware of it, the traditional owners gave permission for the Balanda [non-Yolngu] staff to go out and investigate," John says.
"They didn't want any of the local Yolngu taking the risk of going near the sacred site, which is deemed as powerful and potentially a threat to people's wellbeing."
Where did it come from?
Upon the discovery, John's first move was to contact the Australian Border Force about the wreck. Meanwhile, the local rumour mill started churning.
"We heard a story that there was smoke from one of the islands, which currently has no residents on it," he says. "We went to that island and sort of looked around and didn't see any evidence of any survivors."
Being an island community, there was no shortage of sea-craft experts to offer opinions on how the boat got there.
John says a visitor to the island who is "fairly familiar" with wrecked boats looked at the photos and determined that the line of algae suggested it had been upside-down for two or three weeks.
The Australian Maritime Safety Authority (AMSA) told the ABC they had issued six warnings about the wreck to other vessels.
And they're "relatively certain" they know where it came from.
The AMJ Lima
The authority believes the wreck is an Indonesian vessel that capsized on rough seas just off the coast of West Papua in September.
The Indonesian National Search and Rescue Agency (Basarnas) had released a statement on September 13 detailing a distress report from a cold storage logistics company called Sutioso Bersaudara.
The company said one of its fishing boats — with a crew of 24 people — had capsized in bad weather near the port of Merauke in West Papua.
Basarnas says a nearby boat — the AMJ Enam — helped rescue most of the crew, barring a 33-year-old man who couldn't swim, wasn't wearing a life jacket, and was still missing.
Around 24 hours later, the capsized AMJ Lima was next seen by a container ship floating about 200 kilometres north of the uninhabited Wessel Islands, which are part of the Northern Territory.
Australian maritime authorities were then notified and for the following 24 hours — until last light on September 15 — enlisted nearby ships and aircraft to search for any survivors.
The final crew member was declared missing and presumed dead a week after its crew was first rescued.
This would be the last reported sighting of the AMJ Lima for two months.
What happens now?
John doesn't know what will happen to the wreck but he is sure that it's the AMJ Lima — which originally set sail from Lombok Island in August, three months before the wreck was spotted near the territory.
"In my opinion, it is the same boat. Even the way those nets are in that photo, that very prominent keel going down the bottom, to that very square end of the keel where the prop is. The width of the boat, the colour," he says.
"There are so many similarities there that I can confidently say that's the same one."
In a statement to the ABC, Indonesian authorities could not confirm the wreck was the AMJ Lima but provided weight and length dimensions that appear to match the boat found near Murrungga Island.
But a mystery remains: where is the 33-year-old man who was never rescued?
The man had been below deck at the time of the capsize, according to AMSA, and was not seen in the vicinity of the boat at the time of the AMJ Enam rescue.
John worries that if the body is still in the wreck, it could have profound spiritual implications for his Yolngu colleagues and friends.
He says some residents of Murrungga Island were so concerned they "felt they couldn't safely return home … because of some sort of spiritual consequence of the [wreck] being near the sacred site".
Authorities the ABC spoke to about the boat were unable to say when — or if — the wreck would be retrieved. Both AMSA and the Department of Environment Parks and Water Security say it isn't within their responsibilities.
Meanwhile, Northern Territory Police say they're tracking the vessel until it can be safely accessed.
