What to do if you're left in 'Open Water'
By Brian Todd
WASHINGTON (CNN) -- The movie "Open Water" is based on the true story of a couple in 1998 mistakenly left behind by their diving boat, stranding them off Australia's Great Barrier Reef.
Part of the film's attraction is the mystery surrounding the couple's fate.
But after the buzz, does "Open Water" hold water with divers?
CNN spoke to officials at dive training schools and to Joe Schittone, a marine ecologist with the National Oceanic and Atmospheric Administration and co-owner of a Louisiana dive shop, where he says he once dealt with the couple who later went missing.
"They weren't highly experienced divers," said Schittone, "but they knew what they were doing."
Schittone and other diving instructors say the sport is incredibly safe. The Divers Alert Network says of the 2 to 3 million people estimated to dive in a given year around the world, less than 100 fatalities are reported.
As for cases of divers being left behind, Schittone says "it's so rare that you can't study it and say there's a trend."
Schittone and other diving instructors say there are always supposed to be and often are, extensive procedures to keep track of divers.
But the system isn't always foolproof and instructors offer a few helpful tips if you're stranded:
-Immediately drop your weight belt, or extra items like cameras.
-Keep your mask, snorkel and fins, but don't swim, unless you see land or a platform -- you'll only exhaust yourself.
-Although it's not required, it helps to have a so-called "safety sausage" -- a bright, inflatable tube that sticks several feet out of the water.
"You should also have a whistle, and reflective device like a mirror or old CD," cautions Schittone.
Sharks are prominent characters in "Open Water," and filmmakers made no secret of the fact that they purposely attracted sharks by throwing bait into the water before shooting scenes.
"We were controlling their behavior," said Linda Lau, the film's producer.
Experts say sharks that aren't accustomed to being fed stay away from divers.
"Its a rare treat to see a shark when diving ... in reality they get away, when they see divers they skedaddle," says Schittone.
But aside from sharks and basic survival techniques, one expert says the No. 2 priority on diving excursions is making sure all divers are back on the boat. The No. 1 priority: making sure the boat doesn't sink.