History Main / EldritchOceanAbyss

* ''Water Womb World'' is a short indie game involving a scientist exploring a deep part of the ocean to find the real place in which God created the first humans. [[ReligiousHorror What they find may deviate from a bit from how the Bible is normally understood.]]

** ''Literature/GoingPostal'' introduces the notion of areas deep enough that the pressure surpasses the density of sunken objects, causing ghost ships that float on a sea-under-sea.

** ''Literature/GoingPostal'' also introduces the notion of areas deep enough that the pressure surpasses the density of sunken objects, causing ghost ships that float on a sea-under-sea.

* The animated short ''WebAnimation/TheDeep'' features a dark deep-sea ocean full of fish and sea creatures made from various mechanical parts, accompanied by eerie ambient music.

'''Black Mage:''' I ignored the pitiable babbling that issued from their misshapen lips. Their wet gurgles, a noise that had once been words, came to and end when one of the ''things'' outside assaulted our craft. I welcome death.

* ''Literature/{{Discworld}}'': The Gorunna Trench, mentioned a number of times in the series, is the deepest part of the Disc's seas and home to horrific things -- according to some, horrors from the Dungeons Dimensions still lurk within it. ''Literature/TheColourOfMagic'' notes that even {{kraken|AndLeviathan}}s only go through it in pairs, and deep-sea fish keep their lights doused to avoid attracting attention to themselves.

* A Commodore 64 game ''Terror of the Deep'' (one figures there are only so many possible combinations of "deep" and "terror") has you descend in a steampunkish bathysphere into Loch Ness -- meaning, not an ocean, but Administrivia/TropesAreFlexible -- in order to defeat the monsters living in it. The oxygen slowly runs out, they may come from any direction, and you can only look through one window at the time.
* Indy game ''Water Womb World'' involves a Christian scientist hunting for the supposed true origin point of man in Gaspar's Zone, a remote location in the middle of the ocean. Outside his sub in pitch darkness he finds [[TimeAbyss ancient species of fish]], mysterious coral, and [[spoiler: the actual being man evolved from, then becomes one himself]]

** Before N'zoth, there was the underwater super zone of Vashj'ir filled with multiple demigods that take the form of crustaceans the size of cities, faceless ones, and several elites that will oneshot any player foolish enough to attack them.

* The Living Infinite, setting of ''VideoGame/WeNeedToGoDeeper'' is one filled with abnormally large, hostile sea life, along with more bizarre threats including infectious barnacle, underwater robots, and [[spoiler: an EldritchAbomination slumbering at the bottom.]]

* The appropriately named ''VideoGame/MassEffect3'' DLC ''Leviathan''. Shepard investigates some mysterious orbs with MindRape capabilities, and ends up descending into the depths of the ocean inside a specially-built mech. [[spoiler:At the bottom are the ''[[AbusivePrecursors creators of the Reapers]].'' And Shepard ends up browbeating them into helping with the war effort.]]

* In ''VideoGame/{{SOMA}}'', while most of the game takes place in the Pathos-II UnderwaterBase situated on a huge plateau, the last third of the game involves taking a 4000-meter elevator ride down into the Abyss. And to reach sites Tau and Phi, you have to follow a path of barely visible lights while enduring a powerful ocean current [[spoiler: and rabid sea creatures mutated by [[MutagenicGoo Structure Gel]], including a GiantSquid and an enormous [[AlluringAnglerfish angler fish]].]]

* In ''Film/TheMeg'', scientists accidentally release a {{megalodon}} shark[[note]]extinct, and thought to be a shallow-water predator[[/note]] from the Marianas Trench. According to the original novel, megalodons are explained to have evolved into an abyssal species, but are no less horrifying or {{threatening|shark}} for it.

* ''Film/ThePhantomMenace'': The core of the planet Naboo holds vast subterranean oceans, which are inhabited by titanic dinosaur- and eel-like creatures. Jar Jar believes a trip through the Core would be a SuicideMission, but the main characters survive with only minor incident.
* In the horror-survivor film ''Film/{{Sweetheart}}'', the waters immediately surrounding the deserted island are sparkling, clear and shallow...except for an impenetrably dark, perfectly round, and seemingly-bottomless black pit [[spoiler:from which a [[MonstrousHumanoid monstrous]], [[SharkMan shark-like]] predator of unknown origin emerges each night.]]
* ''Film/TheRift'' is about a submarine crew on a doomed rescue mission to an underwater rift full of monsters. Unlike the above films, it came out in March of 1990, just a few months late to the party.

* Creator/HPLovecraft, creator of the ''Franchise/CthulhuMythos'', [[http://chrisperridas.blogspot.com/2006/11/lovecraft-and-hatred-of-seafood.html had an irrational fear of the sea,]] leading to many of his {{Eldritch Abomination}}s bearing traits of aquatic creatures, and many of his threats coming from the ocean's depths.
** ''Literature/TheShadowOverInnsmouth''. The ocean floors are inhabited by the Deep Ones: [[TheAgeless Ageless]], cultish FishPeople who worship {{Eldritch Abomination}}s from beyond the stars and receive strange powers in return. That said, it's the Deep Ones who come to land for mates who are the most troublesome....

* ''Literature/{{Deeplight}}'': The Undersea, a sub-ocean created by human fear and populated by {{Eldritch Abomination}}s. The water is breathable and the crushing pressure that ought exist in the depths is absent. You can swim around with no equipment, but the environment messes with your mind and may leave you with "Marks" (small mutations, a tentacle here, a patch of shell there..).

* ''Film/TheEvilBelow'' is about a cursed shipwreck, guarded by a SeaMonster.

Submersibles and [=ROVs=] have allowed closer study of the ocean depths, and oceanographers don't expect to find Cthulhu. Nevertheless, this is still TruthInTelevision for different reasons: the environmental conditions (low or no light, high pressure, low temperature, low oxygen, and very little food or prey compared to shallow waters) in the midnight,[[note]]"bathypelagic", around 1,000 to 4,000 meters below sea level[[/note]] abyssal[[note]]"abyssopelagic", about 4,000 to 6,000 meters below sea level; ocean floors are included in this zone[[/note]] and hadal[[note]]"hadopelagic", extending down to about 11,000 meters below sea level[[/note]] zones of the ocean have led organisms to evolve traits we land-dwellers tend to consider horrific. For example, many creatures do not have eyes or have evolved special eyes due to the lack of light, and are usually either very dark, transparent, or bright red [[note]]which appears pitch black at such depths[[/note]] in color. This biome is utterly inhospitable to humans, and the logistical difficulties of conducting research in it only adds to these regions' mystery.

* Creator/HPLovecraft, creator of the ''Franchise/CthulhuMythos'[', [[http://chrisperridas.blogspot.com/2006/11/lovecraft-and-hatred-of-seafood.html had an irrational fear of the sea,]] leading to many of his {{Eldritch Abomination}}s bearing traits of aquatic creatures, and many of his threats coming from the ocean's depths.

* A small slew of movies dealing with this trope came out in 1989 -- basically SpaceIsolationHorror movies that [[SpaceIsAnOcean swapped space for the deep ocean]]. The best-remembered (and probably just best) of these was ''Film/TheAbyss'' by Creator/JamesCameron, which features a United States SEAL team trying to salvage a destroyed nuclear submarine in the deep ocean, and encountering strange creatures dwelling there.
** ''Film/{{Leviathan|1989}}'' is about an underwater mining crew 15,000 feet below the surface that slowly dwindles due to attacks by a mutant creature.
** ''Film/LordsOfTheDeep'' is about a deep sea research station crew encountering mysterious psychic creatures.
** ''Film/DeepStarSix'' has an underwater military outpost attacked by a big worm-like SeaMonster.
** ''Film/TheEvilBelow'' is about a cursed shipwreck, guarded by a SeaMonster
** ''Film/TheRift'' is about a submarine crew on a doomed rescue mission to an underwater rift full of monsters. Unlike the above films, it came out in March of 1990, just a few months late to the party.

* A small slew of movies dealing with this trope came out in 1989 - basically SpaceIsolationHorror movies that [[SpaceIsAnOcean swapped space for the deep ocean]]. The best-remembered (and probably just best) of these was ''Film/TheAbyss'' by Creator/JamesCameron, which features a United States SEAL team trying to salvage a destroyed nuclear submarine in the deep ocean, and encountering strange creatures dwelling there.

* ''Film/ItCameFromBeneathTheSea'' opens with a submarine exploring a deep ocean trench, where they have their first encounter with the [[TentacledTerror giant octopus]]. Unfortunately, it is not content to stay down there.
* ''Film/GodzillaKingOfTheMonsters2019'' has a sequence in the UnderwaterRuins of an ancient, Godzilla-worshiping city deep within the Hollow Earth. The ruins are infused with radiation from the Earth's core, making it Godzilla's preferred place to rest and heal after a fight.

* In ''Literature/TheVoyageOfTheDawnTreader'', when Lucy peers over the gunwales and views deep-sea merfolk settlements beneath the crystal clear water, she notes that the towns and castles are all on sea mounts and other high peaks. She surmises that deeper, darker, colder waters must be considered undesirable or even scary places by the sea-dwellers, in an inversion of how steep, icy mountaintops aren't much favored by humans.
* ''Literature/TwentyThousandLeaguesUnderTheSea'' is an early instance of this trope. Mostly, it emphasizes the idea of the ocean as a place of wonderful nature, but in the deeper parts, the ''Nautilus'' crew encounter some very strange things, including a GiantSquid and the UnderwaterRuins of {{Atlantis}}.

* A Commodore 64 game ''Terror of the Deep'' (one figures there are only so many possible combinations of "deep" and "terror") has you descend in a steampunkish bathysphere into Loch Ness -- meaning, not an ocean, but Administrivia/TropesAreFlexible -- in order to defeat the monsters living in it. The oxygen slowly runs out, they may come from any direction, and you can only look through one window at the time.
* Indy game ''Water Womb World'' involves a Christian scientist hunting for the supposed true origin point of man in Gaspar's Zone, a remote location in the middle of the ocean. Outside his sub in pitch darkness he finds [[TimeAbyss ancient species of fish]], mysterious coral, and [[spoiler: the actual being man evolved from, then becomes one himself]]

* The animated short ''WebAnimation/TheDeep'' features a dark deep-sea ocean full of fish and sea creatures made from various mechanical parts, accompanied by eerie ambient music.

* In Creator/AlredLordTennyson's poem "The Kraken", [[KrakenAndLeviathan the monster in question]] lurks in such a location. This poem was, unsurprisingly, a big influence on ''Literature/TheCallOfCthulhu'', listed above.

* The ''Franchise/CthulhuMythos'':
** Creator/HPLovecraft, original creator of the mythos, [[http://chrisperridas.blogspot.com/2006/11/lovecraft-and-hatred-of-seafood.html had an irrational fear of the sea,]] leading to many of his {{Eldritch Abomination}}s bearing traits of aquatic creatures.
** The ocean floors are inhabited by the Deep Ones: [[TheAgeless Ageless]], cultish FishPeople who worship {{Eldritch Abomination}}s from beyond the stars and receive strange powers in return. That said, it's the Deep Ones who come to land for mates who are the most troublesome....
** The "nightmare corpse-city" of R'lyeh lies at the floor of the remote South Pacific. In it, the Great Old One Cthulhu [[SealedEvilInACan lies in deathless slumber]], waiting for {{the Old Gods}}' return.

* ''Literature/{{Deeplight}}'': The Undersea, a sub-ocean created by human fear and populated by {{Eldritch Abomination}}s. The water is breathable and the crushing pressure that ought exist in the depths is absent. You can swim around with no equipment, but the enviroment messes with your mind and may leave you with "Marks" (small mutations, a tentacle here, a patch of shell there..).

* ''Film/TheAbyss'' by Creator/JamesCameron features a United States SEAL team trying to salvage a destroyed nuclear submarine in the deep ocean, and encountering strange creatures dwelling there.
* The AlwaysChaoticEvil creatures who reside in the Trenches in ''Film/{{Aquaman|2018}}'' are all horrific monsters. They actually [[TheMorlocks evolved from original Atlanteans into what they are]] because of the natural environment of trenches.
* ''Film/{{Leviathan|1989}}'' is about an underwater mining crew 15,000 feet below the surface that slowly dwindles due to attacks by a mutant creature.

* The animated short ''[[https://www.youtube.com/watch?v=AK18bdUEWSs The Deep]]'' features a dark deep-sea ocean full of fish and sea creatures made from various mechanical parts, accompanied by eerie ambient music.

* A Commodore 64 game ''Terror of the Deep'' (one figures there are only so many possible combinations of "deep" and "terror") has you descend in a steampunkish bathysphere into Loch Ness -- meaning, not an ocean, but TropesAreFlexible -- in order to defeat the monsters living in it. The oxygen slowly runs out, they may come from any direction, and you can only look through one window at the time.

** ''VideoGame/SubnauticaBelowZero'' continues this trend with the Crystal Cavern and [spoilers:Fabricator Cavern], the two deepest biomes in the game. Generally with both games, the deeper you go, the more twisted the landscape becomes and more dangerous creatures you encounter.

** ''VideoGame/SubnauticaBelowZero'' continues this trend with the Crystal Cavern and [spoiler:Fabricator Cavern], the two deepest biomes in the game. They're filled with deadly Shadow Leviathans and surreal terrain shapes.

* Numerous biomes in ''VideoGame/{{Subnautica}}'' count as this, but the Inactive Lava Zone, Active Lava Zone, and Lost River, and the Abyss biomes fit this trope the best -- being inhabited by enormous monsters such as the Sea Dragon and Ghost Leviathans, and littered with the fossils of even more massive creatures.

* In ''VideoGame/{{Bloodborne}}'', the ocean is one of the [[EldritchAbomination Great Ones']] preferred homebases, particularly of the one known as Mother Kos. In ''The Old Hunters'' DLC, you actually get to visit the [[Literature/TheShadowOverInnsmouth Innsmouth]]-like Fishing Hamlet where Kos washed ashore in the backstory and even to find her NotQuiteDead corpse.

Submersibles and [=ROVs=] have allowed closer study of the ocean depths, and oceanographers don't expect to find Cthulu. Nevertheless, this is still TruthInTelevision for different reasons: the environmental conditions (low or no light, high pressure, low temperature, low oxygen, and very little food or prey compared to shallow waters) in the midnight,[[note]]"bathypelagic", around 1,000 to 4,000 meters below sea level[[/note]] abyssal[[note]]"abyssopelagic", about 4,000 to 6,000 meters below sea level; ocean floors are included in this zone[[/note]] and hadal[[note]]"hadopelagic", extending down to about 11,000 meters below sea level[[/note]] zones of the ocean have led organisms to evolve traits we land-dwellers tend to consider horrific. For example, many creatures do not have eyes or have evolved special eyes due to the lack of light, and are usually either very dark, transparent, or bright red [[note]]which appears pitch black at such depths[[/note]] in color. This biome is utterly inhospitable to humans, and the logistical difficulties of conducting research in it only adds to these regions' mystery.