Description: On the rebound after a devastating break-up, Lisa (Mandy Moore) is ready for adventure while on vacation in Mexico. Even still, she needs a little extra persuasion when her daring sister Kate (Claire Holt) suggests they go shark diving with some locals. Once underwater in a protective cage, Lisa and Kate catch a once in a lifetime, face-to-face look at majestic Great Whites. But when their worst fears are realized and the cage breaks away from their boat, they find themselves plummeting to the bottom of the seabed, too deep to radio for help without making themselves vulnerable to the savage sharks, their oxygen supplies rapidly dwindling.