Which is scarier, outer space or the ocean? This age-old question (okay, maybe not quite that old…) is up for debate (certainly, the unique horrors of space have been discussed a few times on Tor.com), but in reality the two aren’t all that different. Both are hostile to human life, both are terrifyingly vast, and both inspire fear of the unknown. Really, there’s no need to blast off into the inky void of space to find alien life, when you can dive down into the inky depths of the ocean and find creatures so bizarre that they may as well be alien. And with more than 80% of the ocean still unexplored, there are countless as-of-yet undiscovered horrors lurking around down there.
The sea, lakes, and rivers are common leisure spots during the warmer months of the year, but who knows what lies in wait beneath the surface? The five horror books below explore that very question, conjuring up scares that will turn thalassophiles into staunch thalassophobes. Let’s dive into these tales that are, depending on your perspective, either perfect or terrible to read while relaxing by a body of water…
Into the Drowning Deep by Mira Grant
There are quite a few sea creatures—both real and mythological—that slot perfectly into horror narratives without much effort. Think sharks and krakens. But in Into the Drowning Deep (2017) Mira Grant takes mermaids, which in most people’s minds have been thoroughly Disneyfied, and manages to twist them into something truly terrifying. Forget Ariel and her wide-eyed fascination with humans—the mermaids in Grant’s novel have teeth, and they’re keen to use them.
A few years before the book is set, a film crew had been sent to the Mariana Trench—the deepest part of the ocean—to film a mockumentary about mermaids. Only the film turned out, quite unexpectedly, to be a documentary and everyone aboard the Atargatis was killed (as covered in Grant’s 2015 novella Rolling in the Deep). The footage of the incident was declared a hoax, but now a new crew, comprised mostly of scientists, has been sent to figure out what really happened.
Grant masterfully ramps up the tension at the beginning of the novel before everything erupts in an explosion of bloody fangs and fins. The delightfully vicious mermaids are inventively designed and yet actually feel plausible. You’ll probably pick up this story for the killer aquatic creatures—and they are the stars of the show—but the fun and fleshed-out cast of characters will also help reel you in.
A House at the Bottom of a Lake by Josh Malerman
Instead of a clear supernatural threat or horrifying lake monster, Josh Malerman offers up ambiguity and the uncanny in A House at the Bottom of a Lake (2016). The novella follows teenagers James and Amelia, who for their first date decide to take a canoe out to explore a chain of lakes. They end up finding a hidden lake…and at the bottom of that lake is, you guessed it, a house. But this house isn’t displaying the wear and tear to be expected of a building that has been submerged in water.
As James and Amelia fall in love with each other over the course of the story, they also fall into a deep obsession with the strange underwater house. Don’t expect gross-out gore or full-on frights because you’ll be left feeling unsatisfied. Rather, their dives down to the out-of-place building are filled with the implicit dread that lies in unsettling eeriness and suffocating claustrophobia.
The Deep by Nick Cutter
Nick Cutter’s The Deep (2015) is not to be confused with either Rivers Solomon’s The Deep (2019), which is about a society of mer-people descended from enslaved women who were thrown overboard while crossing the Atlantic, or Alma Katsu’s The Deep (2020), which is an alternate history tale about spooky shenanigans aboard the Titanic. In Cutter’s take on the title, a disease that causes lethal forgetfulness has ravaged the planet, but a substance that might be a cure-all has been found in the dark depths of the Mariana Trench.
A small research base has been set up at the bottom of the trench to study the strange jelly-like substance, known as ambrosia. As this is a horror book, of course things go very wrong. The Deep provides terror of the crushed-under-miles-of-water variety, but Cutter also throws many other scares into the blender of this novel: There’s extremely graphic gore, an unhinged scientist, insect-related horror, and even clowns. For those mindful of content warnings, there’s animal cruelty and child abuse (both of which are so vividly described that I ended up skimming certain sections).
From Below by Darcy Coates
From Below (2022) by Darcy Coates unfolds over two equally terrifying timelines. In the main plot, we follow a team of divers who are filming a documentary about a fancy ocean liner that mysteriously vanished in 1928 and has just been discovered on the seafloor in a location far off of its plotted course. In the secondary plot, we get flashbacks to the final days aboard the Arcadia as things start to spiral out of control.
The events that led to the Arcadia’s sinking aren’t revealed until the reader is a fair way through, so From Below is definitely a slow-burn horror. While the explicitly spooky elements take a while to step out of the murky shadows, in the meantime, the dives down into the shipwreck provide ample scares (if, like me, the very idea of swimming through a shipwreck freaks you out). Coates crafts a chilling atmosphere—both figuratively and literally—beneath the waves. The lack of oxygen in the freezing waters of the Gulf of Bothnia means that the wreck is unnervingly well-preserved and the descriptions of its interior are lushly creepy.
The intriguing mystery of how the ship sank mixed with the descriptions of very real problems experienced by the divers—such as limited air, lack of light, and becoming trapped—is enough to make me not want to even dip a single toe into the sea any time soon.
The Fisherman by John Langan
All of the books on this list so far have been set almost entirely on or under the water; John Langan’s The Fisherman (2016) spends a little more time on dry land, but that doesn’t make its aquatic scares any less impactful. Langan blends the otherworldly horror of Lovecraft with the real-world horror of grief.
Our two main characters are Abe and Dan, widowers who are at different points in their grieving journeys. For Dan, his loss is fresh and all-consuming; for Abe, it is distant but ever-present. The two come together and find solace in fishing, but unfortunately it’s also fishing that leads them down a dark path. They hear tales of Dutchman’s Creek, a place that may offer a miraculous cure for their grief, although exactly how lies firmly in spoiler territory.
The middle section of The Fisherman is given over to a story-within-the-story that provides the historical background of the mysterious Dutchman’s Creek. Rather than merely feeling like a springboard into the climactic end of the novel, the story that is related to Abe and Dan could easily stand on its own as an effective piece of Lovecraftian weird fiction. The two narratives eventually come together to form a tale that’s as heartbreaking as it is horrifying.
This list is far from exhaustive, of course, so please leave your own recommendations for water-based horror novels in the comments below!
Lorna Wallace has a PhD in English Literature and is a lover of all things science fiction and horror. She lives in Scotland with her rescue greyhound, Misty.