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."
