Below [2002] HorrorSuspenseful and claustrophobic, Below is an underrated masterpiece following a doomed submarine crew during WWII as they descend into hell.
The Burning Sea AKA Nordsjøen [2021] ThrillerMore technical and without much melodrama, The Burning Sea is a refreshing albeit a bit contained Norwegian disaster movie.
DeepStar Six [1989] Science fictionDeepStar Six is an undemanding and character-oriented underwater science fiction thriller reminiscent of Alien with a good cast and decent atmosphere.
Leviathan [1989] Science fictionLeviathan borrowed so many elements from Alien and The Thing, that we shouldn't be mad but amazed at what ultimately turned out to be a charming homage.
The Rift [1990] HorrorIf you're a fan of eighties underwater movies check out The Rift, a charmingly stereotypical movie with decent practical effects and good pacing.
Breaking Surface [2020] ThrillerFast-paced and intense, Breaking Surface is a high-concept thriller unfolding in real-time and following two sisters who get in trouble during a dive.
47 Meters Down [2017] ActionSleek looking but very commercial shark movie that will keep you interested for an hour and half. If you're looking for some harmless fun, look no more.
Sphere [1998] Science fictionBased on a novel by Micheal Crichton, Sphere is an engaging movie with a distinctly scientific approach, an all-star cast, and a mysterious atmosphere.