Movies You Shouldn’t Watch If You Have Thalassophobia

While the surface of the ocean is terrifying, what's underneath can be much worse. The movie 47 Meters Down (2017) utilizes the same premise as other aquatic horror films, but it does them one better by stranding its two actresses not just in the ocean with sharks - but beneath it. 

When two sisters vacation in Mexico, they're talked into cage diving to see sharks up close. Of course, something inevitably goes wrong, and the cage ends up sinking to the bottom of the ocean, surrounded by sharks. 

Open Water might manage to trigger thalassophobia with its title alone. The film is based on the real-life account of two scuba divers who are left behind to fend for themselves when their dive boat fails to take an accurate headcount. Basically, Open Water is the worst film imaginable for thalassophobes.

On top of the film's true-life inspiration and the aforementioned open water, the creators filmed with real sharks. 

Notable for its one-person cast, All is Lost stars Robert Redford as a man trying to survive in the open ocean after his boat's hull is torn open by a stray shipping container. Because Redford is alone at sea, the film has almost no spoken dialogue. Instead, viewers are thrust into Redford's shoes as he attempts to repair the ship, survive a storm, and face other hazards.

Ultimately, the ship capsizes, and he finds himself on an inflatable life raft in the open ocean - surely a nightmare for anyone who has thalassophobia. 

An isolated underwater research facility is the setting for this 1999 sci-fi horror flick about genetically engineered sharks who, of course, attack the flooded facility during a storm at sea. Directed by Renny Harlin (Die Hard 2, Cliffhanger), Deep Blue Sea is as much an action movie as it is a horror flick.

There's enough open water, flooding chambers, and, of course, sudden shark attacks to make just about anyone squirm at least a bit.

While sailing to Indonesia, a group of friends capsize their boat and try to swim to a nearby island. Unfortunately, the water is also inhabited by a great white shark. This harrowing Australian survival film - the second from writer-director Andrew Traucki - is based on a true story. 

The real-life origins of this open-ocean horror story are sure to make it even more terrifying for thalassophobes.

What's scarier than being out in the middle of the ocean? Being in a submarine hundreds of feet below the surface. And what's even more terrifying than that? Being in a haunted submarine hundreds of feet below the surface.

For some thalassophobes, the claustrophobic interior of the submarine may provide ample insulation from the reminders of the dark waters all around, and the supernatural trappings might be enough of a distraction to forget the crushing depths temporarily. However, there are plenty of scenes in Below that will undoubtedly trigger your thalassophobia.