Chris (played by Finn Cole), on the verge of marriage to Morag (Bobby Rainsbury), has one last job he needs to finish: a month-long assignment maintaining pipelines at the bottom of the North Sea. The team is headed up by his friend, seasoned diver Duncan (Woody Harrelson), and includes Dave (Simu Liu), who seems doubtful about Chris’s abilities. They set out into a severe storm, with massive waves battering their vessel, and as the two men descend to the seabed, things quickly take an unexpected turn. Simultaneously, the ship above loses its stability, leaving the divers isolated, and then Chris finds himself trapped by his own ropes, initiating what becomes a frantic rescue effort against a rapidly dwindling timeframe. The film draws from actual events that are inherently fascinating, and there’s some genuinely unsettling underwater footage—including shots taken with real diving suits—but unfortunately, the performances aren't particularly strong overall, and the script doesn't do much to assist Harrelson, who feels both underutilized and prone to overacting. While the direction is sometimes tense, it ultimately fails to develop these characters in a compelling way or fully convey how perilous their work of repairing essential energy systems truly is. This might be due to the fact that much of the action occurs hundreds of feet below the surface in complete darkness, or because the divers are encased in bulky industrial suits—or perhaps a combination of both. Ultimately, the film diminishes much of the danger present in the original story and leaves you feeling somewhat unfulfilled.

Source on TMDB