15 Movies Like Iron Lung (2026) That Will Make You Fear the Unknown

Iron Lung is about as simple as a horror film can be: a prisoner is locked into a tiny submarine and sent to explore an ocean of blood on a lifeless moon, with almost no way of seeing what is outside. Markiplier (Mark Fischbach) wrote, directed and stars in this adaptation of David Szymanski’s cult video game. You can read more on our Iron Lung page.

If you want more of that feeling, we picked 15 films where people are sealed in small vessels, stranded far out in space, or faced with something they cannot understand. Each entry tells you what the film is about, why it is similar to Iron Lung, what sets it apart and where you can stream it. Three of them are found footage and are marked FF in the table. And if you also like survival films with ticking clocks, our lists of movies like Whalefall and movies like Fall 2: Deadpoint have 30 more.

At a Glance: Our Dread-O-Meter

Fifteen films, one scale. 🩸 means a light shiver; 🩸🩸🩸🩸🩸 means you are staring at the walls and hoping they hold. Tap a title to dive straight into its entry.

Sealed In: Movies Like Iron Lung in Tiny Vessels and Flooded Rooms

Iron Lung takes place in a space you could cross in two steps. These five films keep their characters in submersibles, pods and flooded houses, where the walls are close, the air is limited and the instruments are the only way to understand the world outside.

1. The Chamber (2016)

A small crew goes down in a cramped submersible for a secret job on the sea floor. When the mission goes wrong, the vessel is stuck deep below the surface, and the people inside have to work out what to do before the air and the nerves give out.

Why it’s similar to Iron Lung: The closest physical match on the list: a small metal capsule, failing equipment, and a world outside the hull that nobody can reach. Like Iron Lung, the film is mostly about people in a tiny space learning what pressure does to them.

What sets it apart: It is a lean British thriller with a small cast and no monster, so the threat is the water and each other. It is less stylish than Iron Lung, and the story is more of a standard thriller, but it makes good use of its one location.

Watch it here:

2. Oxygen (2021)

A woman wakes up inside a sealed cryogenic pod with no memory of who she is. The only voice she has is the pod’s artificial assistant, and the oxygen level keeps falling.

Why it’s similar to Iron Lung: One person in a tiny space with almost no information, and a system that tells her only part of the truth. It captures the helplessness of Iron Lung: you only know what the instruments tell you.

What sets it apart: Alexandre Aja directed this French Netflix film, and Mélanie Laurent carries almost every minute of it. It is more of a puzzle than a horror film, and the answer to where she is gives it a sci-fi turn. It also works for readers of our movies like Whalefall list, since the oxygen clock is the same.

Watch it here:

3. Underwater (2020)

After an earthquake wrecks a deep-sea drilling station, the survivors walk across the ocean floor in heavy suits to reach an escape pod. Something else is moving in the dark water around them.

Why it’s similar to Iron Lung: Crushing pressure, murky visibility and a threat that is slowly revealed to be much bigger than anyone expected. That is the same hint of cosmic horror under the water that Iron Lung builds on.

What sets it apart: William Eubank’s film is loud and fast where Iron Lung is quiet, and Kristen Stewart leads a crew that is thrown into the disaster from the first minute. The late reveal borrows from Lovecraft. It is also in our movies like Whalefall list, there for the oxygen.

Watch it here:

4. The Deep House (2021)

Two YouTubers who film abandoned places dive into a lake in France to explore a house that stands at the bottom, complete with rooms, stairs and furniture. They quickly learn why nobody has been inside it for years.

Why it’s similar to Iron Lung: A first-person exploration of a dark, flooded space with a camera and a limited air supply. It plays a lot like a horror video game, which is exactly where Iron Lung came from. Check out our page about The Deep House for more info about the movie.

What sets it apart: Directors Julien Maury and Alexandre Bustillo, who made Inside, mix found footage with ghost-story horror. It is shot in the water with limited light, and it is slower and quieter than their earlier work. It is the film on this list that sits closest to our genre.

Watch it here:

5. The Abyss (1989)

An oil-rig crew is sent to a deep-sea habitat to help the military search for a lost nuclear submarine. At the bottom, they find something in the water that is not from this world.

Why it’s similar to Iron Lung: A cramped underwater setting, pressure, and a presence in the dark that humans cannot fully understand. It is the best-known film about meeting the unknown at the bottom of the ocean.

What sets it apart: James Cameron’s film is more awe than horror, with a love story at its center and a famous water-filled breathing scene. It is the gentlest film here, and the director’s cut adds a lot. Watch it if you want the wonder side of the deep rather than the dread.

Watch it here:

Deep Space: Movies Like Iron Lung Among the Stars

Iron Lung’s moon is lonely in a way that only space can be. These six films send small crews to places where no one can help them, and two of them, Europa Report and Apollo 18, are found footage.

6. Europa Report (2013)

A private crew travels to Jupiter’s moon Europa to look for life beneath the ice. The story is put together from the footage recorded by the ship’s cameras and the crew’s own recordings.

Why it’s similar to Iron Lung: An isolated crew, a long distance from help and a discovery that is bigger than they are. Like Iron Lung, it keeps its characters small against something enormous, and it lets the silence do the work.

What sets it apart: Sebastián Cordero presents it as recovered footage, so it is more sober than most found footage. It is thoughtful science fiction, with real dread in the second half. We have it in our database as a film worth seeing: read our Europa Report page.

Watch it here:

7. Apollo 18 (2011)

Presented as footage from a secret US mission to the Moon in 1974. Two astronauts land and find that someone was there before them, and that the rocks are not as still as they look.

Why it’s similar to Iron Lung: Two people alone in an environment that is trying to kill them, with limited light and a lot of silence. The footage style makes the cramped lander feel as tight as Iron Lung’s submarine.

What sets it apart: Gonzalo López-Gallego’s film is the more horror-oriented of our two space found footage picks, and the grainy archive look is its main selling point. The story is thin, but the atmosphere works. Read our Apollo 18 page for the full verdict.

Watch it here:

8. Event Horizon (1997)

A rescue crew is sent to find the Event Horizon, a spaceship that vanished seven years ago and has just reappeared near Neptune. Something has come back with it.

Why it’s similar to Iron Lung: Cosmic dread and madness in a closed environment, with a threat that is not a creature but a place. It shares Iron Lung’s sense that the universe holds something humans should not look at.

What sets it apart: Paul W.S. Anderson’s film is much gorier and louder than Iron Lung, with Sam Neill and Laurence Fishburne in an industrial-gothic ship. The effects are dated, but the images are still shocking. It is a cult favorite for good reason.

Watch it here:

9. Alien (1979)

The crew of the commercial towing ship Nostromo wakes up to answer a signal from a nearby moon. They bring something aboard that has no interest in negotiating.

Why it’s similar to Iron Lung: Industrial machinery, narrow corridors and the slow realization that the creature is beyond anything the crew understands. It is the model for every later film of small crews trapped with something alien.

What sets it apart: Ridley Scott’s film is more patient than Iron Lung would suggest, and the sound design and the design of the creature are what make it a classic. It is also the most famous film on the list, so most readers will already know it, but it is worth a rewatch for the pacing.

Watch it here:

10. Aniara (2018)

A giant passenger spaceship carrying people to Mars after Earth becomes unlivable is knocked off course. With no way to turn around, the passengers have to live with the fact that they are drifting away from everything.

Why it’s similar to Iron Lung: Absolute isolation and a creeping despair that has no monster at all. Of everything on the list, this is the closest to the emotional low point of Iron Lung.

What sets it apart: This Swedish film, directed by Pella Kågerman and Hugo Lilja, is based on a poem by Harry Martinson. It is slow, bleak and philosophical, and it covers years rather than hours. It is a good choice if the existential side of Iron Lung stayed with you.

Watch it here:

11. Moon (2009)

Sam Bell is nearing the end of a three-year contract at a mining base on the far side of the Moon, with only a robot assistant for company. After an accident, he starts to realize that something is wrong with the base and with him.

Why it’s similar to Iron Lung: One man, one location, no outside contact and a mystery that unfolds through the details of the room. It captures the loneliness that Iron Lung builds its dread on.

What sets it apart: Duncan Jones’s debut is gentle and sad rather than frightening, and Sam Rockwell carries almost the entire film. The dread is in the idea, not in the scares. It is a thoughtful pick for readers who want sci-fi over horror.

Watch it here:

The Unknown: Cosmic Horror Like Iron Lung

The most unsettling part of Iron Lung is that you never fully understand what is out there. These four films also leave the threat partly unexplained, whether it is a creature, a zone or a force that no one can name.

12. The Void (2016)

A police officer takes a wounded man to a rural hospital that is half-empty. Soon the building is surrounded by hooded figures, and something inside the walls starts to change the people who are trapped there.

Why it’s similar to Iron Lung: Cosmic horror in a closed space, with something that is not explained and does not need to be. It has the same disturbing organic imagery that makes Iron Lung’s world so unpleasant.

What sets it apart: Jeremy Gillespie and Steven Kostanski made it with practical effects, and the monsters are rubber, latex and slime that look more physical than most CGI. It is a hospital siege rather than a lonely voyage, and it is much busier than Iron Lung.

Watch it here:

13. The Endless (2017)

Two brothers who escaped a strange desert commune years ago decide to visit it again. The people there look the same as they did a decade ago, and the land around the camp does not behave the way it should.

Why it’s similar to Iron Lung: The threat is never fully shown, and that is the point. Like Iron Lung, it is about a force that is much larger than the characters and cannot be understood from where they stand.

What sets it apart: Justin Benson and Aaron Moorhead, who also play the brothers, made it for very little money, and the low-budget look suits the mystery. It is more of a puzzle than a scare, and it rewards patience. It works best if you let the ideas settle.

Watch it here:

14. Annihilation (2018)

A biologist joins an all-female expedition into Area X, a stretch of coast covered by a shimmering barrier. Inside, the landscape and the creatures change in ways that nobody can explain, including the people who enter.

Why it’s similar to Iron Lung: An unknown environment that cannot be understood, and an expedition that slowly discovers it is out of its depth. The strange, beautiful hostility of the Shimmer is the closest match to Iron Lung’s blood ocean.

What sets it apart: Alex Garland’s film is bigger, more beautiful and more cerebral than most of the list, and it was adapted from Jeff VanderMeer’s novel. It has one extremely tense bear scene. Natalie Portman leads, and the ending is open to interpretation.

Watch it here:

15. The Thing (1982/2011)

Researchers at an Antarctic station find out that a dog they took in is not what it seems. The creature can imitate any living thing, and soon nobody can trust anybody.

Why it’s similar to Iron Lung: Total isolation, a shapeless threat and paranoia in a cold, enclosed place. It has the same feeling of being cut off from the world as Iron Lung, with something you cannot see or fully understand.

What sets it apart: John Carpenter’s film is a paranoia thriller as much as a monster film, and Rob Bottin’s practical effects are still among the most disturbing ever made. Kurt Russell leads. It is a classic, and still one of the most frightening films about not trusting what you see. If you do not like older films, there is a 2011 version with the same title, a prequel that shows what happened at the Norwegian camp before the original begins.

Watch it here:

Where to Start

For the closest match in setting, start with The Chamber or Oxygen. For found footage, watch Europa Report, Apollo 18 or The Deep House. For pure cosmic dread, try Event Horizon or Annihilation. And if the loneliness is what stayed with you, watch Aniara or Moon.

Want more films where you cannot get out? Try our list of movies like Whalefall, with tight spaces and oxygen running out, or our list of movies like Fall 2: Deadpoint for heights and survival thrillers.