Author B.C. Cartmell in his 1978 book "Let's Go Fossil Shark Tooth Hunting," includes this account:
"In the 1960s along the outer edge of Australia's Great Barrier Reef, an 85-foot ship experienced engine trouble, which forced it to weigh anchor for repairs. Although the men subsequently refused to openly report what they had seen for fear of public ridicule, the captain and his crew later told friends of sighting an immense shark as it moved slowly past their ship. Whitish in color, they were awed by its size. It was as long, if not longer, than their boat! Experienced men of the sea, they too were certain the creature was not a whale." So what was it? Other writers, such as author Rick Emmer, suggest it could have been Megalodon.