Underwater plunges viewers into the crushing depths of the Mariana Trench, where a crew of industrial researchers faces unimaginable terror. When a catastrophic earthquake destroys their deep-sea drilling facility, mechanical engineer Norah (Kristen Stewart) and the surviving crew must navigate through the wreckage of their station to reach safety. What begins as a desperate survival mission quickly transforms into a nightmarish confrontation with mysterious, predatory creatures that have been awakened from the ocean's deepest recesses.

Director William Eubank creates relentless tension through claustrophobic set design and atmospheric pressure that feels palpable throughout the film's tight 95-minute runtime. Kristen Stewart delivers a grounded, physically demanding performance as the pragmatic Norah, supported by Vincent Cassel as the station's captain and T.J. Miller providing moments of dark humor. The film effectively blends sci-fi elements with creature-feature horror, drawing comparisons to classics like Alien while establishing its own identity in the deep-sea survival genre.

Viewers should watch Underwater for its intense, immersive atmosphere and well-executed practical effects that make the underwater setting feel genuinely perilous. The film maintains a brisk pace from its explosive opening sequence to its haunting conclusion, offering consistent thrills and impressive creature designs that will satisfy horror and sci-fi enthusiasts alike. While the plot follows familiar survival horror beats, the unique deep-sea environment and strong ensemble cast make this a compelling watch for anyone seeking tense, aquatic horror with solid production values and effective scares.