History Main / EldritchOceanAbyss

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.

* ''VideoGame/IronLung'' takes place entirely at the bottom of an uncharted ocean on an alien moon where who-knows-what is living down there. And to make things even more bizarre and creepy, it's an ocean apparently made up of ''[[RiversOfBlood blood]]''. And to make it even worse, this is the ''fourth'' blood ocean moon they've found.

* ''VideoGame/IronLung'' takes place entirely at the bottom of an uncharted ocean on an alien moon where who-knows-what is living down there. And to make things even more bizarre and creepy, it's an ocean apparently made up of ''[[RiversOfBlood blood]]''.

* 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.

* ''VideoGame/TerrariaCalamity The Calamity Mod'' replaces one of your world's oceans with the Sulfurous Sea, an ocean full of HollywoodAcid for water and a large pit leading to the Abyss, a dark, tight biome full of aggressive predators. It also circumvents most means of breathing in water, instead just having them increase how long you can stay down there before you start drowning, with the sole exception of Amidias' Blessing, which instantly wears off as soon as you take damage. And don't think about mining open an air pocket, because you'll just [[MortonsFork start taking damage from the toxic air]]. As you go deeper in the Abyss, you use more air in less time and it becomes harder to see, and more dangerous monsters make their presence known, including the mod's most dangerous boss as of yet, the [[{{Superboss}} Eidolon Wyrm]], and teleporting with the Rod of Discord or Normality Relocator [[NoFairCheating has it attack you almost instantly]]. However, there are useful items down there that will make your trip worth the while, such as weapons that can be useful against the Slime God and [[DiscOneFinalBoss Wall of Flesh]], and materials for later on in the game. At the very bottom of the Abyss is the Terminus, an item that allows you to play through the mod's BossRush, but Yharon also drops it. [[spoiler:For killing the Eidolon Wyrm, you also get the Halibut Cannon, which used to drop from every enemy in the Abyss at a very low drop rate.]]

* ''[[VideoGame/TerrariaCalamity The Calamity Mod]]'' for ''VideoGame/{{Terraria}}'' replaces one of your world's oceans with the Sulfurous Sea, an ocean full of HollywoodAcid for water and a large pit leading to the Abyss, a dark, tight biome full of aggressive predators. It also circumvents most means of breathing in water, instead just having them increase how long you can stay down there before you start drowning, with the sole exception of Amidias' Blessing, which instantly wears off as soon as you take damage. And don't think about mining open an air pocket, because you'll just [[MortonsFork start taking damage from the toxic air]]. As you go deeper in the Abyss, you use more air in less time and it becomes harder to see, and more dangerous monsters make their presence known, including the mod's most dangerous boss as of yet, the [[{{Superboss}} Eidolon Wyrm]], and teleporting with the Rod of Discord or Normality Relocator [[NoFairCheating has it attack you almost instantly]]. However, there are useful items down there that will make your trip worth the while, such as weapons that can be useful against the Slime God and [[DiscOneFinalBoss Wall of Flesh]], and materials for later on in the game. At the very bottom of the Abyss is the Terminus, an item that allows you to play through the mod's BossRush, but Yharon also drops it. [[spoiler:For killing the Eidolon Wyrm, you also get the Halibut Cannon, which used to drop from every enemy in the Abyss at a very low drop rate.]]

-->A tiny deep sea fish investigated the probe from up close, startling Ami by filling the screen with a set of fangs that even Rabixtrel would have envied.

* ''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. It [[FollowTheLeader kickstarted]] a whole wave of this type of movie, including ''Deep Star Six'', ''The Evil Below'', ''Lords of the Deep'', ''Leviathan'', and ''The Rift'', all of which are listed below, and came out in 1989 and 1990.

* ''Podcast/OnTheThreshold'': A recurring motif, with several characters in altered mental states (recurrently dreaming, subjected to non-consensual neurosurgery, etc.) [[YouCannotGraspTheTrueForm explaining their experiences]] in terms of descending into the ocean and encountering or being pursued by unseen or incomprehensible entities

* ''VideoGame/BeyondTwoSouls'': A late-game chapter is set in and around a pseudo-Chinese deep sea base where the Chinese military is conducting experiments on a nearby Infraworld portal. Since precious little in poor Jodi's life ever goes right, things spiral out of control quickly until the portal starts unleashing swarms of hostile Entities that proceed to lay waste to the facility and everyone in it, thus truly turning the place into an eldritch horror scenario.

** The Underwater Islands biome consists of several huge chunks of rock suspended between the surface and the ocean floor some 500 meters below, given buoyancy by colonies of Floater organisms. Navigating them successfully requires three-dimensional thinking, and going over the edge of one of the islands can be unnverving as you see nothing but dark waters beneath you.

** The Grand Reef is the deepest of the standard surface biomes, and approaching it from a neighboring biome involves watching the sea floor suddenly fall away in a vertigo-inducing drop. There's little to see in the depths but occasional glowing Membrane Trees and bizarre spherical Anchor Pods tied to the side of the cliffs by creepers, which means the local Ghost Leviathans are nearly invisible until they scream and come charging out of the gloom to try and ram you. It has a cave system, the Deep Grand Reef, that goes even further down.

** Beneath Sector Zero are the Crystal Caves [[spoiler:and Fabricator Caverns]], a cave network dominated by enormous, faintly-glowing crystal columns and strangely geometric mineral formations. They're home to the Shadow Leviathans, the most aggressive and persistent sea monsters in the series thus far.

* ''VideoGame/WorldOfWarcraft'': The [[EldritchAbomination Old God]] N'zoth was chained at the bottom of an oceanic trench by the Titans. Since then he has corrupted the surrounding sea life, creating the [[PuppeteerParasite zoatroids]] and mutated fish through which he can communicate. The Naga city of Nazjatar and Azshara's Eternal Palace lead to the abyss where players inadvertently free N'zoth. Before N'zoth, there's 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.

[[folder:Tabletop Games]]
* In ''TabletopGame/{{Exalted}}'', there is a sea comprised entirely of different types of oil. It's part of the vast mechanical body of [[EldritchAbomination Autochthon]], and embodies his madness with occasional bubbles of Void-tainted oil that sabotages any purpose it's put to. It's also patrolled by mechanical servitors and guardian spirits (guardians of the god, not of human life). But the worst part is that it holds so many resources that [[CityOnTheWater Loran]]'s people must dive into it ''anyway''. The alternative is slow starvation.
[[/folder]]

[[folder:Web Comics]]
* Subverted in ''Webcomic/EightBitTheater'': [[https://www.nuklearpower.com/2006/07/25/episode-724-somewhere-beyond-the-sea-my-elder-god-stands-on-golden-sands/ Despite Black Mage's impressive narration about the horrors of the deeps,]] they don't actually encounter anything particularly mind-breaking.

* ''VideoGame/Bioshock2'': The [[TheAlcatraz Persephone prison]] is suspended over a huge ocean trench, with glass walkways showing it. [[spoiler: [[BigBad Sofia Lamb]] had set up explosives intended to drop the entire structure into this trench, but whoever survives is determined by your actions in the game.]]

* ''[[VideoGame/TerrariaCalamity The Calamity Mod]]'' replaces one of your world's oceans with the Sulfurous Sea, an ocean full of HollywoodAcid for water and a large pit leading to the Abyss, a dark, tight biome full of aggressive predators. It also circumvents most means of breathing in water, instead just having them increase how long you can stay down there before you start drowning, with the sole exception of Amidias' Blessing, which instantly wears off as soon as you take damage. (And don't think about mining open an air pocket, because you'll just [[MortonsFork start taking damage from the toxic air]].) As you go deeper in the Abyss, you use more air in less time and it becomes harder to see, and more dangerous monsters make their presence known, including the mod's most dangerous boss as of yet, the [[{{Superboss}} Eidolon Wyrm]], and teleporting with the Rod of Discord or Normality Relocator [[NoFairCheating has it attack you almost instantly]]. However, there are useful items down there that will make your trip worth the while, such as weapons that can be useful against the Slime God and [[DiscOneFinalBoss Wall of Flesh]], and materials for later on in the game. At the very bottom of the Abyss is the Terminus, an item that allows you to play through the mod's BossRush, but Yharon also drops it. [[spoiler:For killing the Eidolon Wyrm, you also get the Halibut Cannon, which used to drop from every enemy in the Abyss at a very low drop rate.]]

* [[https://i.pinimg.com/474x/ac/a3/f8/aca3f835653a81946f2e919e5227b885--deep-blue-sea-under-the-sea.jpg This picture of the contents of the ocean,]] which gets more terrifying the lower you scroll, with the absolute bottom of the ocean containing [[spoiler:as [[AntiClimax a joke]], WesternAnimation/SpongeBobSquarePants]].

* [[https://i.pinimg.com/474x/ac/a3/f8/aca3f835653a81946f2e919e5227b885--deep-blue-sea-under-the-sea.jpg This picture of the contents of the ocean,]] which gets more terrifying the lower you scroll, with the absolute bottom of the ocean containing [[spoiler: Spongebob Squarepants]].

Not to be confused with TimeAbyss. May overlap with EldritchLocation, although the work can portray the deep ocean as relatively "normal" but just home to creepy things. Also compare SpaceIsAnOcean, as stories about exploring the deep sea may share genre conventions with space stories and portray sea life in a manner similar to aliens, and OceanMadness, the feeling of insanity after being out (or in this case, ''down'') at sea for too long.

* In ''ComicBook/SubMariner: The Depths'', Atlantis is depicted as some dark lost city instead of the bustling country it usual is in Marvel. Namor himself is a silent HumanoidAbomination.

%%* ''VideoGame/EccoTheDolphin''

** ''VideoGame/SubnauticaBelowZero'' continues this trend with the Crystal Cavern and [[spoiler:Fabricator Cavern]], the two deepest biomes in the game.

* In ''[[Literature/JackelianSeries From The Deep Of The Dark]]'', the invading [[HordeOfAlienLocusts sea-bishops]] originally emerged from a portal at the bottom of a deep ocean trench, and are conspiring to re-open it so their countless fellows can join them.

-->Below the thunders of the upper deep\\
Far, far beneath in the abysmal sea
* 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.

* One late-game chapter of ''VideoGame/BeyondTwoSouls'' is set in and around a pseudo-Chinese deep sea base where the Chinese military is conducting experiments on a nearby Infraworld portal. Since precious little in poor Jodi's life ever goes right, things spiral out of control quickly until the portal starts unleashing swarms of hostile Entities that proceed to lay waste to the facility and everyone in it, thus truly turning the place into an eldritch horror scenario.
* The [[TheAlcatraz Persephone prison]] in ''VideoGame/Bioshock2'' is suspended over a huge ocean trench, with glass walkways showing it. [[spoiler: [[BigBad Sofia Lamb]] had set up explosives intended to drop the entire structure into this trench, but whoever survives is determined by your actions in the game.]]
* PlayedWith in ''VideoGame/{{Bloodborne}}''. In the BackStory, the [[ExtranormalInstitute Byrgenwerth]] scholars had originally discovered evidence of the [[EldritchAbomination Great Ones]]' existence in the old underground labyrinth of Pthumeru, but their first actual encounter with a Great One in the flesh took place in the [[Literature/TheShadowOverInnsmouth Innsmouth]]-like Fishing Hamlet where a Great One named Kos washed up ashore. From this one discovery, the scholars have jumped to the false conclusion that ''all'' Great Ones are linked to great bodies of water, and subsequently focused much attention on the ocean. Lady Maria, in particular, after cutting her ties to Byrgenwerth and joining Laurence's newfound Healing Church, spearheaded the research into human ascension by having Research Hall subjects imbibe sea water until their heads turned into fleshy blobs, then extracting "brain fluid" from said heads, and feeding it back to them until [[BodyHorror only the head blobs remained]]. Needless to say, this was a dead end, and Maria [[MyGodWhatHaveIDone committed suicide after realizing it]]. It wasn't until after the Choir was formed to take over her research that the Church realized that while ''Kos'' dwelt in the ocean, ''most'' Great Ones actually reside in the cosmos above their heads.

* Both ''VideoGame/EndlessOcean'' games have levels themed around diving into deep ocean trenches and meeting animals such as goblin sharks and sperm whales.

* Implied in ''VideoGame/GuildWars2'', though the deepest sea is never shown in game. The depths of the Unending Ocean are occupied by the Deep Sea Dragon, an EldritchAbomination who's sent the other residents packing. Such residents include the Krait, an AlwaysChaoticEvil race of snake-people, and the Largos, a mysterious race of creepy (though not necessarily evil) humanoids with VaderBreath.

--->Within the darkness there are fish, and things that are not fish, and things that are not anything a land-dweller was ever meant to see. This is a school of one such creature, and it doesn't look friendly. It looks mostly like teeth and hiveminded appetite.

* 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]].'' Shepard ends up browbeating them into helping with the war effort.]]
* Implied to be the case in ''VideoGame/SaltAndSanctuary''. The monsters of the world, referred to as Kraekan, all believed to originate from the sea, and many even boast aquatic features even though they appear to be terrestrial. [[spoiler:The ending further implies that the island, itself an EldritchLocation, exists within the depths of the ocean.]]
* 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. 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]].]]

* The eponymous ''VideoGame/SunlessSea'' is this, naturally - the entire game involves exploring the "Unterzee", a colossal, ever-shifting, underground expanse of water full of dangers and oddities. Late-game dialogue crosses this with SpaceIsAnOcean, serving as a SequelHook for ''VideoGame/SunlessSkies''.

** The ''Zubmariner'' expansion lets you submerge and visit the abysses themselves... the zeefloor is already an EldritchLocation of the highest calibers, but the abysses are where [[HumanoidAbomination the Lady in Black]] lives.
* The 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 a time.
* ''Water Womb World'' is a short indie game involving 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]].

* In ''VideoGame/WorldOfWarcraft'' the [[EldritchAbomination Old God]] N'zoth was chained at the bottom of an oceanic trench by the Titans. Since then he has corrupted the surrounding sea life, creating the [[PuppeteerParasite zoatroids]] and mutated fish through which he can communicate. The Naga city of Nazjatar and Azshara's Eternal Palace lead to the abyss where players inadvertently free N'zoth.
** Before N'zoth, there's 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.
* As the title implies, ''VideoGame/XComTerrorFromTheDeep'' is about an independent military force funded by the world's governments that battles ancient alien invaders originating from deep within the Earth's oceans. The game borrows heavily from [[Creator/HPLovecraft Lovecraftian]] influences, going so far as the BigBad being a [[EldritchAbomination sleeping ancient evil]] that the X-Com forces must keep the aliens from awakening.

** The Caliginous Abyss is themed entirely around being a horrific, alien place in the deepest part of the ocean. When the player heads there to look for the mother Sea Monkee, they face several surreal non-combat encounters -- such as fish with twisted human faces, incongruous mother-hen messages carved into rock walls or written out of glowing sea life, areas of the seafloor carved by the passage of hundreds and hundreds of tentacled somethings -- and combat encounters against things such as enormous eyes staring out of the darkness, slithering armored things, a twisted parody of [[https://en.wikipedia.org/wiki/Mr._Peanut Mr. Peanut]] and a group of carnivorous things referred to simply as a "school of many".

'''Black Mage:''' I alone maintain a gimmer of humanity. I fear it is fading fast.\\

[[folder: Comic Books]]

* Numerous biomes in ''VideoGame/{{Subnautica}}'' count as this, but the Inactive Lava Zone, Active Lava Zone, and Lost River, and the Crater Edge 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.
** ''VideoGame/SubnauticaBelowZero'' continues this trend with the Crystal Cavern and [[spoiler: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.

* ''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.

* ''The Rift'' 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...

* 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 a 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.]]
* ''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 a bit from how the Bible is normally understood.]]
* ''We Need To Go Deeper'' is an indie game involving a submarine crew navigating a labyrinth of tunnels while fending off giant sharks and whales. Later updates to the game, however, have added increasingly Lovecraftian monsters.

* ''VideoGame/{{Barotrauma}}'' is an indie game involving a submarine navigating the abyssal depths of Europa's frozen oceans, which contain nightmarish deep-sea predators as well as the remnants of a mysterious alien civilization. Insanity is a persistent theme, with a "psychosis" status effect causing players to hallucinate nonexistent threats, half of the major factions being unhinged cults, and a couple of [[SocialDeductionGame traitor]] permutations centring around members of the crew turning murderously insane.

* ''VideoGame/{{Barotrauma}}'' is an indie game involving a submarine navigating the abyssal depths of Europa's oceans, fending off attacks from often nightmarish deep-sea predators.