LOS ANGELES - More than 40 years ago, Americans were afraid to go into the water as Jaws scared the daylights out of a generation of ocean swimmers.

Hollywood is hoping for a repeat this summer with the movie 47 Meters Down. There have been more than 50 shark movies since Steven Spielberg made cinematic history with Jaws in 1975.

This year's shark movie, which will open in the United States on Friday, takes place almost entirely underwater.

Sisters Lisa and Kate - played by Mandy Moore and Claire Holt - are on vacation in the Gulf of California, and it becomes clear that they should avoid climbing aboard a flimsy boat that belongs to Taylor (Matthew Modine). They also probably should not get inside Taylor's rusty shark cage to plunge into the water and observe the predators up close.

Modine's character attracts the sharks by pouring blood into the water before the cage breaks away from the boat and drops to the ocean floor. The two young women with little diving experience find themselves in the dark with less than an hour of air in their oxygen tanks and surrounded, of course, by hungry sharks.

"What I found far more terrifying is the prospect and premise of drowning, of running out of air," Moore says. "That's my biggest fear. That's far more terrifying than sharks, which are terrifying enough."

Director Johannes Roberts decided that once the women plunged into the ocean there was no need for scenes on the surface.

"I had no interest in going back to reaction shots with Taylor and the other boys on the boat," he says.

"Imagine if in Gravity, you kept cutting to ground control. It would have killed the movie," he says, referring to the 2013 Oscar winner, a film about astronauts stranded in space.

For 47 Meters Down, Moore and Holt spent eight hours a day for eight weeks inside a 6-meter-deep water tank. The film was shot mainly in sun-deprived Britain, far from Mexico's bright Pacific coast. A few scenes were made in the Dominican Republic.

The actresses could communicate via a special radio set, but communication with the rest of the film crew was via hand signs, while the director's instructions were delivered through a speaker inside the water tank.

Last year, just 81 unprovoked shark attacks were reported worldwide, according to the International Shark Attack File. None were reported in Mexico.

The chances of being attacked by a shark are nearly one in 4 million, according to the International Wildlife Museum based in Tucson, Arizona.

And yet, a large mouthful of sharp teeth and fear of the deep sea add up to shark bait for Hollywood producers.

Agence France - Presse

Director Johannes Roberts attends the premiere of 47 Meters Down in Los Angeles. Reuters