In an incident eerily similar to the 2004 blockbuster
movie Open Water, last month a British couple
drifted away from their dive boat in Australian
waters. Louise Woodger, 29, and her fiancé Gordon
Pratley, 31, were making their first unaccompanied
open water dive from the Sea-Esta out of Townsville,
Queensland, when they got caught in an unusually
strong current at Wheeler Reef, 55 miles offshore.
The pair entered the water about 10 a.m., but
  when they surfaced, their boat was just a "speck in the
  distance" before it slipped out of view. The 1998 disappearance
  of Americans Tom and Eileen Lonergan
  (the inspiration for Open Water) sparked a crisis of
  confidence in north Queensland's dive industry,
  which led to tighter safety regulations for dive boats.
  In that case, the boat operator didn't discover the
  Lonergans missing until two days after the boat had
  returned to port. Only a couple of pieces of their
  equipment were found. 
Fortunately, new safety procedures worked better
  this time. The skipper realized two divers were missing
  when he completed a head count immediately
  after the other divers were on board. He called the
  Australian Coast Guard, which launched an air and
  sea search.  
Nevertheless, Woodger and Pratley drifted for six hours. They could see rescue helicopters and search
boats, but couldn't attract their attention. They used
their dwindling air supply to inflate their BCDs, huddled
together, and swam around to warm up. When
they saw a shark circling beneath them, they made a
decision not to look down any more. Eventually they
were picked up by their own boat about 3:50 p.m.
Coast Guard skipper Jon Colless, who ferried the
  exhausted pair to safety, said they were at risk of "very
  large" sharks. He said, "They were freakishly lucky that
  search was called early in the day, that the weather was
  going down, it had been a bit lumpy ... and the skipper
  of the dive boat was right on the ball, did everything
  right." Pro Dive, the company which operated
  the tour, insisted that the boat crew had followed strict
  procedure, and that the unusually strong current
  - caused by a high tide - caught everyone by surprise.
  Despite suffering seasickness, exhaustion and mild
  hypothermia, Woodger and Pratley expressed nothing
  but praise for the Sea-Esta's crew.  
And yet the London Times reported that the recently
  certified couple was allowed to go off on their own
  while the other divers on board "were having a lesson
  with an instructor." Perhaps the Sea-Esta should
  have sought out safer waters for neophyte divers. The Queensland Courier Mail editorialized, that Australian
  authorities, " should thoroughly review the circumstances
  which led up to this incident and determine
  whether, and how, the diving code of practice should
  be tightened to ensure nothing like it happens again."