US snorkeller abandoned at Great Barrier Reef

Queensland's Great Barrier Reef. Photo / Supplied

A US tourist has been forced to swim for help after realising he was left behind on a Great Barrier Reef snorkelling trip.

The case has eerie echoes of the Tom and Eileen Lonergan tragedy, the American couple left behind on a dive off Port Douglas in January 1998.

Their horrific ordeal was the inspiration for the movie Open Water, which told of their desperate fight for survival after they surfaced to find their boat had left them behind.

The incident tightened the headcount regulations for reef tour operators, but these were overlooked on the Passions of Paradise boat, which left US tourist Ian Cole stranded on Saturday.

The 28-year-old told The Cairns Post newspaper he panicked when he pulled his head from the water at Michaelmas Cay and found the boat had left.

He was forced to swim to another vessel owned by the same company, whose employees radioed for Passions of Paradise to come back.

The staff member who failed to properly perform the headcount has reportedly been sacked, and the incident reported to Marine Safety Queensland and Workplace Health and Safety.

Mr Cole's money was refunded, and he was given a $200 restaurant voucher.

It took two days for the Lonergans to be reported missing and their bodies were never found.

It's presumed they drowned or were taken by sharks.

- AAP