As a rec skipper that fishes the Midwest to Exmouth coast in a 21 foot glass boat, I hate to think the damage that would occur from running into the 2m x 2m metal cylinder that washed up at Green head.  A decky mate came across an oxy/acetylene cylinder bobbing off Wedge while on a cray boat that would of been very ugly to come across at pace. We often wonder what happened when a boat goes down and space junk doesn't normally come to mind.