In the new movie 47 Meters Down, Mandy Moore and Claire Holt play sisters vacationing in Mexico.

On a whim, they decide to go shark-diving. But after the cable breaks, they find themselves trapped 154 feet below the surface, fighting for their lives.

“I think it’s in a category all it’s own,” Moore said. “I mean, it’s…”

“It’s a survivor story,” Holt said.

“It’s a survivor story, but I think what sets it apart is tis is a film that takes place primarily underwater,” Moore said.

“It’s definitely a thriller and a suspense film and a horror film, but it’s also a story about a relationship, about these two sisters who are relying on each other to survive,” Yani Gellman said.

Both actresses learned to scuba dive for the film.

“We had a quasi-crash course in diving training and went on one open ocean dive, which was fantastic and terrifying, but it didn’t prepare us for what we would encounter filming eight weeks underwater,” Moore said.

Matthew Modine plays the boat captain. He said no matter the challenge, a good actor always says “yes!”

After this experience, Moore and Holt are planning to hang up their scuba gear.

“There’s no fear, but there’s no pressing need to go scuba diving any time soon,” Moore said.

“I’d like to sit on the cactus instead of scuba diving. True story, true story,” Holt said. “They are a necessary part of the ecosystem that I don’t need to come across at any part in my life. We can fear and respect them from a distance.”