[[quoteright:256:[[VideoGame/DonkeyKongCountry1 https://static.tvtropes.org/pmwiki/pub/images/underthesea.bmp]]]]
[[caption-width-right:256:How exactly is he ''riding'' that swordfish?]]
->''"Darling, it's better\\
Down where it's wetter,\\
Take it from me!"''
-->-- '''Sebastian''', ''Disney/TheLittleMermaid''

Aquatic videogame levels have been a staple of Nintendo games since ''VideoGame/SuperMarioBros1'', but can be seen in other games as well. Typical underwater enemies are [[ThreateningShark sharks]], octopuses, squid, urchins, electric eels, jellyfish ([[BreadEggsBreadedEggs and sometimes]] ElectricJellyfish), {{clam|Trap}}s, and some common fish like basses, rays, and mackerels with basic swimming patterns to serve as underwater [[TheGoomba goombas]] if the former options are a little too threatening. Expect some UnderwaterRuins every now and again for decoration.

Human heroes, such as [[Franchise/SuperMarioBros Mario]], often swim fully clothed, without being weighed down or otherwise impeded -- it's as if WaterIsAir.

Of course, there are three problems with the underwater level: one, swimming, two, slower movement, and three, [[OxygenMeter drowning]]. (Or [[SuperNotDrowningSkills not]].) DownTheDrain levels are especially prone to special water-based hazards and hindrances, as detailed on that page.

Compare SharkTunnel. These can enter ThatOneLevel territory, depending on how difficult it is to swim or how small the OxygenMeter is.

Named for the [[UsefulNotes/AcademyAward Oscar]]-winning song from ''Disney/TheLittleMermaid''.
!!Single-Level Examples:
[[folder:Action Adventure]]
* Water levels abound in almost every ''Franchise/TheLegendOfZelda'' game:
** ''VideoGame/TheLegendOfZeldaOcarinaOfTime's'' Water Temple was so bad that the ''[[UpdatedRerelease Master Quest]]'' rerelease (which upped the difficulty in all levels) is said to be ''easier'' than the original. Which means they replaced one of the rooms with one that had half a dozen Stalfos in it. Problems include slow mobility through the submerged hallways, and backtracking between water level switch areas numerous times, which involved many treks through said hallways. Time after time you had to go in circles, Hookshotting every which way to collect keys, adjust water levels, and avoid enemies with indestructible shells. Then the battle with Dark Link will take a large amount of HP out of you, though [[GuideDangIt it can be replaced by MP loss if you have Din's Fire, and both could be lowered by doing the trading sidequest for the Biggoron's Sword]] (or the Megaton Hammer, which most players will have by that point in the game). And then when you get the Longshot, you have to go down this river where there are several whirlpools that act like bottomless pits, forcing you to start over. And then you have to get the Big Key to fight Morpha, who is relatively easy, but has a chance to do 5 Hearts of damage by simply using his standard attack, if you're unlucky. The UsefulNotes/Nintendo3DS remake has the Water Temple as the only dungeon with substantial changes beyond the obvious cosmetic changes, such as [[ColourCodedForYourConvenience color-coding]] the paths that you need to follow to change the water level, and making the Iron Boots a button-based item, eliminating the menu-switching problem.
** ''VideoGame/TheLegendOfZeldaMajorasMask'' has the entire ocean province known as the Great Bay. Within the Great Bay is the Great Bay Temple, where the puzzles revolve around trying to get the water to keep flowing through to a central point of the dungeon.
** ''[[VideoGame/TheLegendOfZeldaOracleGames Oracle Of Ages]]'' has an actual seafloor as part of the overworld, with the Zora town leading to the WombLevel [[CallBack inside of Jabu-Jabu]].
** This is actually averted for ''[[VideoGame/TheLegendOfZeldaTheWindWaker The Wind Waker]]'' and ''[[VideoGame/TheLegendOfZeldaPhantomHourglass Phantom Hourglass]]'', surprisingly considering where the games take place (respectively the Great Sea and the World of the Ocean King). There are no true underwater dungeons and the water is opaque and cannot be dove into or even swam in for more than a short period. The closest example of a water level in ''Wind Waker'' is the Tower of the Gods, which only features water rising and lowering at timed intervals on the first floor. In the case of ''[[VideoGame/TheLegendOfZeldaSpiritTracks Spirit Tracks]]'', the Ocean Realm does have a large section underwater (the Ocean Floor) where Link's train can navigate without any issues, but the dungeon accessed within (the Ocean Temple), while being underwater as well, is somehow devoid of water in its room (even as a cosmetic element).
* ''VideoGame/{{Primal}}'' has a full-blown underwater level. Jen is given the Undine form to work and fight underwater while swimming. In an inversion of SuperDrowningSkills, Jen's water form loses health when out of water, and cannot take so much as a step on dry land. Scree, being made of stone, just sinks and walks.
* The Dragon Palace in ''VideoGame/{{Okami}}'' is completely underwater, but the controls are identical to playing above land - jumping, gravity, et al. That includes small ponds that you can drown in. Underwater. You can also shake off this underwater water.
* ''VideoGame/BlasterMaster'''s Stage 5, in addition to having a ThatOneBoss, is almost entirely underwater, so your Rover moves and jumps really slowly, and you don't get the swimming ability for it until after you beat the boss, so to reach certain parts you are forced to swim in just your space suit, making you a sitting duck for the otherwise weak {{Mooks}}. ''Zero'' has its Area 5 amount to the same thing, the big difference being that Jason gets to voice [[ThisIsGonnaSuck how much he is looking forward to this area]], and that Gunvolt has [[PowerNullifier his own]] [[ThatOneBoss problems]].
* [=DeepDive=] from ''VideoGame/AnUntitledStory''. A [[ShapedLikeItself vertical shaft]] of water. Your oxygen is limited, but there are several air sources and OxygenMeter expansions to survive.
* The MetroidVania ''Franchise/{{Castlevania}}'' games often have a water level. ''VideoGame/CastlevaniaCircleOfTheMoon'''s is mostly only shallow puddles of water, and ''VideoGame/CastlevaniaPortraitOfRuin'' has just a single boss, but the rest feature full underwater levels where you're slower and you can jump infinitely in the water. Usually an upgrade is needed to get this far. [[VideoGame/CastlevaniaOrderOfEcclesia Order of Ecclesia]] has two such levels.
* ''VideoGame/{{Alundra}}'' has the optional dungeon Fairy Pond which takes place mostly underwater and houses [[InfinityMinusOneSword one of the best swords in the game]] in it.
* Half of the NES game ''VideoGame/{{Jaws}}'' is fighting sealife underwater. Other half has you sailing your boat between two ports purchasing power ups.
* ''Videogame/JablessAdventure'' has a few underwater areas, featuring fish enemies, a mermaid, and a SCUBA-diving bear.
* The ''VideoGame/TeenageMutantNinjaTurtles'' game for NES had the dam stage where you had to disarm eight bombs underwater.
* ''VideoGame/AValleyWithoutWind'' has both Coastal and Shallow Ocean type areas. Coasts are fairly normal areas with large water hazards, but the oceans are a different beast. It's dark, it's oppressive and reaching the surface takes a full minute. But that's okay, since the acid water will kill you so quickly drowning isn't even modeled, and that's not even starting on the mutated wildlife. Blue Whales make terrifying hostiles when they're about as big as you'd expect, and the less said about [[BossInMookClothing Black Whales]], the better.
* ''VideoGame/{{Shantae}}: Risky's Revenge'' has the underwater sections of Shantae's Lighthouse, Mermaid Cliff, and Seaside Retreat, which Shantae will need to scour with her Mermaid Form to find the three Golden Warp Squids and the entrance to the last dungeon. There's also the SunkenCavern, an UnexpectedShmupLevel where Mermaid Shantae must shoot down or avoid Tinkerbats with Scuba gear, killer fishes, and underwater mines.

[[folder:Action Game]]
* ''VideoGame/JungleHunt'' has one level where the hero attacks crocodiles while swimming.
* The submarine levels in various ''VideoGame/MetalSlug'' games. Stage 5 of ''Metal Slug 4'' takes place on a military cruiser, with pirates put in as the Middle-Eastern sword throwers from ''Metal Slug 2'' with recolored sprites. The stage itself can be [[NintendoHard quite difficult]] until you manage to work your way around the many projectiles. [[https://www.youtube.com/watch?v=XQcJenQCqy4 Click to see the level.]]
* In ''VideoGame/SpiderManAndTheXMenInArcadesRevenge'', Storm's levels take place underwater, presumably so the developers wouldn't have to deal with the fact that Storm can fly. These levels are actually the least NintendoHard in the game.
* ''Franchise/TombRaider''
** ''VideoGame/TombRaiderII'' has large part of the game set in a sunken ship, and ''[[VideoGame/LaraCroftTombRaiderChronicles Chronicles]]'' has a section of the game set in a submarine, and the sea around it.
** ''VideoGame/TombRaiderUnderworld'' fits this trope more than the past titles as some of the stages take places in the Mediterranean sea and later the Arctic sea with underwater temples and so it has more emphasis in underwater gameplay.
* The filtration plant in ''VideoGame/{{Shatterhand}}''.
* ''VideoGame/CaptainAmericaAndTheAvengers'' has Scene 3: "Challenge from the Bottom of the Sea," which is only part underwater.
* The boos fight with Porcupffer in ''VideoGame/MarioPinballLand'' takes place underwater.

[[folder:Fighting Game]]
* The final fight in ''VideoGame/VirtuaFighter 2'' was underwater, slowing your movement.

[[folder:First Person Shooter]]
* The "Pelagic II" and "Deep Sea" missions in ''VideoGame/PerfectDark''.

* The climax of ''[[Website/GaiaOnline zOMG]]'''s first chapter take place almost entirely under the ocean. Luckily, you've just been granted the power to breathe underwater.
* There's also Aqua Road of ''VideoGame/MapleStory''.
* ''VideoGame/KingdomOfLoathing'' has underwater zones for leveling up post-ascension, but they're the least attractive option due to poor returns. Adventuring there costs 2 adventures rather than the standard 1, requires equipment that eliminates item drops and removes or reduces familiar bonuses, and the areas do not drop money.
* Vashj'ir in ''VideoGame/WorldOfWarcraft''.

[[folder:Platform Game]]
* In ''[[VideoGame/BanjoKazooie Banjo-Tooie]]'', Jolly Roger's Lagoon starts out as a GangplankGalleon level, but then they remove your OxygenMeter...
* Most worlds in ''VideoGame/DonkeyKongCountry'' trilogy and ''VideoGame/DonkeyKong64'', include one aquatic level. In these levels, the Kongs can ride or must transform into Enguarde the swordfish to repel enemies. ''Videogame/DonkeyKongJungleBeat'' was the first game Donkey can fight off enemies underwater without any animal buddies. ''VideoGame/DonkeyKongCountryReturns'' surprisingly lacks any water levels but ''VideoGame/DonkeyKongCountryTropicalFreeze'' had a whole world of nothing but water levels. [[AcceptableBreaksFromReality Given the Kong's species, none of them should be able to swim in the first place.]]
* This setting is a staple of the ''Franchise/SuperMarioBros'' series:
** ''VideoGame/{{Super Mario Bros|1}}'', is the first to feature a [[SuperNotDrowningSkills swimming Mario]]. Notably, the MinusWorld is also an underwater level, and it cannot be completed.
** ''VideoGame/SuperMarioLand2SixGoldenCoins'' has two such areas: the Hippo Zone, which can lead to the Space Zone, and the Turtle Zone.
** ''VideoGame/SuperMarioBros3'' has a frog suit that allows Mario or Luigi to swim faster. Makes World 3, a water-based level, much easier.
** In ''VideoGame/SuperMarioWorld'', Mario or Luigi can go underwater, also while riding Yoshi.
** ''VideoGame/SuperMario64'' is the first to include an OxygenMeter, and [[GoodBadBugs water with magical healing properties]], since your health meter and air meter are the same.
** The occasional water level is found in ''VideoGame/NewSuperMarioBros1'', ''VideoGame/NewSuperMarioBrosWii'', ''VideoGame/NewSuperMarioBros2'', ''VideoGame/NewSuperMarioBrosU'', & ''VideoGame/NewSuperLuigiU''.
** ''VideoGame/SuperMarioSunshine'' has elements of this in nearly every single level, but Noki Bay has Mario go underwater with a diving helmet in various underwater ruins type areas.
** ''VideoGame/SuperMarioGalaxy'' has a whole seven worlds/areas with aspects of this setting, with the usual water based enemies that go with it.
** ''VideoGame/SuperMario3DLand'' and its sequel ''VideoGame/SuperMario3DWorld'' have the occasional underwater stage, with ''Land'' being the first 3D Mario game to not have an oxygen meter.
** In ''VideoGame/MarioAndLuigiSuperstarSaga'', the brothers can walk on the ocean floor and use their hand powers (fire and electricity) underwater.
* Most ''Franchise/MegaMan'' games have one of these; while the blue bomber didn't swim except in ''VideoGame/MegaMan8'' (almost-sentient robots must be quite heavy, he did have a Rush upgrade for it in some games though), being underwater made you jump higher, [[SpikesOfDoom not that it was of any help.]] ''VideoGame/MegaManStarForce 2'' has Mess Cove.
* Undertow in ''VideoGame/{{Ristar}}''.
* ''Franchise/SonicTheHedgehog'':
** While many games contain water, Sonic [[SuperDrowningSkills can't swim]], and instead runs along the floor, breathing air from bubbles made by underwater plants. Though if he gets up enough speed in [[VideoGame/Sonic3AndKnuckles Hydrocity]] and later games, he can skip the whole swimming thing and just ''run across the water''.
** As opposed to Sonic's SuperDrowningSkills, Tails, Knuckles and Rouge can swim, and Knux can even get an artificial breather in ''VideoGame/SonicAdventure2'' to dive as long as he wants (and walk on the floor).
** In ''VideoGame/SonicAdvance 3'', Knuckles can swim on top of the water and optionally dive, while Sonic with Cream as his partner has an eternal air bubble on his head when they go into water. The worst part of the water levels were [[NightmareFuel/SonicTheHedgehog nightmares]] thanks to [[CriticalAnnoyance the drowning music]].
** Some actual examples include the UnderwaterRuins levels such as Hydrocity, but Coral Cave in ''VideoGame/{{Sonic Rush|Series}} Adventure'' [[HailfirePeaks mixes it up]] with UndergroundLevel and MinecartMadness.
** Aquatic Relix Zone in ''VideoGame/SonicPocketAdventure''.
** Aquarium Park Zone from ''VideoGame/SonicColors''.
** ''VideoGame/SonicAdventure'' has this mainly in Sonic's Lost World, but almost all the Big stages feature water. Makes sense, considering he's fishing.
** Dry Lagoon and Aquatic Mine from ''VideoGame/SonicAdventure2'' combine this with UnderwaterRuins and RuinsForRuinsSake. Cannon's Core at the end of the game has a massive underwater section that Knuckles must traverse. Hope you got the Air Necklace!
** The Labyrinth of the Sea from ''VideoGame/SonicLabyrinth''.
** Labyrinth Zone in the original ''VideoGame/{{Sonic the Hedgehog|1}}''. One GameMod of it, ''VideoGame/SonicTheHedgehogMegamix'', upgrades it to Misty Maze Zone. Scrap Brain Act 3 also applies, being that it's a more difficult recolour of Labyrinth Zone. It was originally intended to be a sewer system of some sort, but time constraints forced the team to make essentially "Labyrinth Zone Act 4", so it looks a bit out of place.
** Aquatic Ruin from ''VideoGame/SonicTheHedgehog2'', of the UnderwaterRuins variety. More infamously is Chemical Plant however, not for being a full water level, but for the last quarter to have a rising section of pink water that was a major DifficultySpike to players back in the day.
** Hydrocity from ''VideoGame/SonicTheHedgehog3'', also of the UnderwaterRuins variety. Sonic 3 has a ''lot'' of water though, to the point that almost all the zones in the ''Sonic 3'' half of the game feature it to some extent.
** Tidal Tempest in ''VideoGame/SonicCD''.
** Tidal Plant in ''VideoGame/SonicTripleTrouble'' which borders on being DownTheDrain as you spend almost the entire second act underwater.
** Aqua Lake in the UsefulNotes/GameGear version of Sonic 2. Unlike later games, Sonic doesn't run on the water's surface, instead bouncing over it like a skimming stone.
** Aqua Planet in ''VideoGame/SonicChaos'' is different from the other examples in that despite it's name the level doesn't have very much water, it's pretty easy to avoid for the most part, and you're not too likely to drown. This is to the point that many of the series' stages that ''aren't'' dedicated water levels have more water.
** Lost Labyrinth from ''VideoGame/SonicTheHedgehog4'' is this mixed with ''UnderwaterRuins''. There is also Sylvania Castle (same sort of thing) and White Park's third act (the rest is SlippySlideyIceWorld and AmusementPark).
** Water Palace from ''VideoGame/SonicRush''. ''Rush Adventure'' has Coral Cave that was mentioned above, but it also has Pirates Island, another UnderwaterRuins level, only with more anchors, dolphins, and [[RemilitarizedZone weaponry]].
** Blue Marine in ''VideoGame/SonicBlast''.
** Wild Water Ways in ''VideoGame/SegaSonicTheHedgehog''.
** The ''VideoGame/SonicAdvanceTrilogy'' gets these as well. Ice Mountain in ''1'' and Twinkle Snow in ''3'' are both combined with SlippySlideyIceWorld (Dimps likes this combination). Ocean Base in ''3'' is an UnderwaterBase, but features significantly less water. ''Advance 2'' has two pools of water in the first act and that's it, making it a rare 2D Sonic game to not have a dedicated water level.
** ''VideoGame/SonicGenerations'' has some. The HD version features [[VideoGame/SonicTheHedgehog2 Chemical Plant]], which is upgraded to become somewhat more watery than the original's, complete with water rising sections. It also has [[VideoGame/SonicHeroes Seaside Hill]], which wasn't a water level in the first place but was retooled to be UnderwaterRuins for Classic Sonic. The 3DS version features the reappearance of [[VideoGame/SonicRush Water Palace]].
* ''Franchise/{{Metroid}}'':
** Maridia in ''VideoGame/SuperMetroid'', and the sunken frigate in ''VideoGame/MetroidPrime''.
** Sector 4 (AQA) in ''VideoGame/MetroidFusion'', and the Torvus Undertemple in ''VideoGame/MetroidPrime2Echoes.''
** ''VideoGame/MetroidOtherM'' doesn't have a dedicated water sector, but [[JungleJapes Sector 1]] and [[SlippySlideyIceWorld Sector 3]] have significant portions of underwater sections. These are infuriating because you ''have'' the Gravity Suit that allows you to move underwater unhindered, but it isn't authorised until extremely late into the game.
* ''VideoGame/WarioLand'' has had a few of these settings.
** The first has water levels in Sherbet Land and the SS Tea Cup areas, the second has the Ruins Under the Sea and the fourth game has Mystic Lake (not quite the sea, but it has the marine wildlife and features you'd see in an ocean).
** ''VideoGame/WarioLand Shake It'' has various underwater submarine shooter type levels (Wavy Waters and Creep Blue Sea being examples).
* Quaria in ''VideoGame/{{Bug}}!''. Filled with many fish enemies, [[ArtisticLicenseBiology fire-spitting moray eels]] ([[ArtisticLicensePhysics yes, underwater]]), [[GiantEnemyCrab crabs]], [[AsteroidsMonster starfish]] and clams. Oh, and the obligatory giant octopus/squid, which served as the boss.
* ''VideoGame/{{Athena}}'' has the World of Sea, where Athena can use a necklace to transform herself into a mermaid.
* In ''VideoGame/CommanderKeen Episode 4: Secret of the Oracle'', the Well of Wishes was the obligatory underwater level where you can't jump or shoot, and swimming controls are rather awkward. Its waters are home to numerous mines and the one and only Dopefish. Water in other places simply [[SuperDrowningSkills kills you at a touch]].
* In ''VideoGame/SpyroTheDragon'', Spyro had SuperDrowningSkills, so the first game didn't use water. However, subsequent games gave him the ability to swim and sent him to levels that were mainly water, which were usually ''very annoying''.
* ''VideoGame/RaymanOrigins'' had several underwater levels, but they averted the frustrating part with fantastic swimming controls, and you could actually be just as agile as you are on land.
* ''VideoGame/LittleNemoTheDreamMaster'' has the fourth level, Night Sea.
* ''VideoGame/{{Karnov}}'' has Stage 5, where Karnov can move faster underwater with the aid of a diving helmet. Karnov's fireballs, unlike Mario's, are not prevented by immersion.
* In ''VideoGame/SlySpy'', the protagonist dons a scuba suit to go underwater for the fourth and seventh stages, which feature ''Film/{{Thunderball}}''-style harpoon combat.
* ''VideoGame/{{Something}} series'':
** There is a section of swimming in the Lost Path's switch palace exit. It's difficult because of the Phantos.
** The level called Only Water Level in Something is the only pure water level in Something. It's unique because of the blue Angry Sun pursuing Mario at all times.
** Star Ocean in Something Else. It's filled with stars, Cheep-Cheeps, and Electric Jellyfish. Also, some of the stars are Rotodisc sprite-swaps and they want to kill Luigi.
* ''VideoGame/DisneyPrincessEnchantedJourney'' has Ariel's world.
* ''Barney's Hide & Seek Game'' on the UsefulNotes/SegaGenesis has the fourth level which Barney himself says is "Under the Sea".
* The world "In the Drink" in ''VideoGame/MonkeyShines''.
* "Lots O'Fish" and "Lots O'Jellyfish" on page five of ''VideoGame/YoshisStory''.
* Overload Ocean in ''VideoGame/KirbyPlanetRobobot'' which is also industrialized given the game's theme.
* ''WesternAnimation/TinyToonAdventures'' games:
** In the 1991 [[UsefulNotes/NintendoEntertainmentSystem NES]] LicensedGame of the same name, the second act of the second stage takes place underwater. If enough power is stored up in the '''POW''' meter, a spin move can be performed to knock out enemies with an underwater tornado. The level is also much easier if you [[CharacterSelectForcing play as Plucky]], due to his enhanced swimming abilities.
** Several levels in ''[[VideoGame/TinyToonAdventures Buster's Hidden Treasure]]'' take place underwater. While Buster cannot drown, he has no way to attack the sea creature enemies in the water aside from [[SmartBomb summoning Little Beeper]].
* ''The [[WesternAnimation/TheItchyAndScratchyShow Itchy and Scratchy]] Game'' has "The Pusseidon Adventure", which serves as the fourth level of the game. Enemies include oysters that shoot pearls, electric eels, and miniature Scratchy robots donned in scuba gear. The [[UnderwaterBossBattle boss of the stage]] is Scratchy in a submarine.
* The sixth level of ''VideoGame/TheFlintstonesTheRescueOfDinoAndHoppy'' takes place underwater. The level is somewhat easier if Fred collects the "Dive" move from one of the bonus stages.
* Sog Ee's Realm in ''VideoGame/SnakePass'' is set mostly underwater.
* In ''VideoGame/ThetaVsPi7'' there are several underwater levels, most of which are in the sea but one of which is in King Pi�s castle. The challenge is that fish aren't vulnerable to normal attacks so need to be lead to their death or outrun.

[[folder:Puzzle Game]]
* ''VideoGame/{{Repton}} Around the World'' includes the Oceans scenario, considered to be the game's most difficult.


[[folder:Racing Game]]
* ''VideoGame/SuperIndieKarts'' has the Shutshimi track Seaweed Speedway, an underwater track where you see various sea creatures, including a jellyfish that can spin you out when you run into it.
* ''VideoGame/SnowboardKids 2'' has Turtle Islane (no relation to the [[TurtleIsland trope of the same name]]), the second half of which takes place on the seafloor. Unlike most racing game examples, the snowboarders are fully submerged in water. They don't need to breathe air though.
* Ever since ''VideoGame/MarioKart 7'' introduced underwater racing as a mechanic, many courses are either completely this theme, such as Dolphin Shoals or Cheep Cheep Lagoon; become this theme as a returning course, such as [[VideoGame/MarioKartWii Koopa Cape]] going from SharkTunnel to this; or have this theme mixed with another theme, such as Wario Shipyard mixing GangplankGalleon with it or Sherbet Land's SlippySlideyIceWorld allowing you to travel into the frozen lake.

[[folder:Role Playing Game]]
* Atlantica in ''VideoGame/KingdomHeartsI'', which is a world based on ''Disney/TheLittleMermaid'', the {{Trope Namer|s}}. Unfortunately, many players [[ScrappyLevel didn't like the level]] thanks to its unintuitive control scheme, so the developers "fixed" it for [[VideoGame/KingdomHeartsII the sequel]] by replacing it with a (thankfully optional) [[UnexpectedGameplayChange rhythm game]].
* ''VideoGame/FinalFantasyVI'' has the Serpent Trench, in which [[FridgeLogic three party members all cram their heads into one diving helmet]] and ride an underwater current while fighting various aquatic enemies, occasionally stopping at half-submerged caves to raid InexplicableTreasureChests.
* There is no specific underwater level in ''VideoGame/FinalFantasyX'' but the game has three party members able to breathe underwater so various parts of Spira have underwater access such as Besaid Island, Mt Gagazet, Baaj Temple and the Submerged Ruins where your characters are able to fight underwater too.
* The Atlantis mission in ''VideoGame/MarvelUltimateAlliance'' The difficulty of operating underwater is {{technobabble}}d away by the presence of special nanites that allow the heroes to survive and fight even while underwater. Considering characters like Storm, Silver Surfer and Ghost Rider can already do fine underwater, they could have just let everyone else sit out.
* The final quest on Manaan in ''VideoGame/KnightsOfTheOldRepublic'' requires you to walk at the bottom of the ocean in a protective suit that slows you down to turtle-speed, while avoiding the dangerous wildlife. For many players, it counts as ThatOneLevel.
* ''VideoGame/{{Wizardry}} 8'' has the Bayjin Shallows and Mount Gigas Water Caves. Despite preventing fire magic from working, the water areas are ''not'' the resident ScrappyLevel. ''That'' title is reserved for Bayjin, the PalmtreePanic level you're trekking underwater to get to.
* In ''VideoGame/PokemonRubyAndSapphire'', the Dive HM makes it possible to go underwater in certain regions of Hoenn. In fact, this is the only way to reach certain areas, like the entrance to Sootopolis City. Underwater areas also have patches of seaweed home to a small variety of aquatic Pokemon only found there. Dive was absent in Gen IV, but returned in ''VideoGame/PokemonBlackAndWhite'', though it doesn't see nearly as much use. In Ruby & Sapphire's remakes, more is added to the diving areas including a new class of trainers, the Divers, and a greater variety of wild Pokemon.
** One thing worth noting is that while these are the only games that actually let you go ''underwater'', aquatic environments are a part of every game. Instead of diving, you ride your Pokémon across it.
* Bottomsup Bay in ''VideoGame/FossilFighters''. The player walks fully-clothed along the bottom of the ocean, looking for fossils. There are also sharks when the area is first unlocked.
* ''VideoGame/{{Mother 3}}'' has the Sea Floor Dungeon between Tazmily Village and Tanetane Island. Lucas and company can't run underwater, and can only replenish their oxygen meter by [[MakesJustAsMuchSenseInContext kissing robotic mermen who breathe the air into them]].
* Appears in some games in the ''VideoGame/MightAndMagic'' series
** The Shoals in ''VII'', entered late in the game. You can't cast magic, you have to wear wetsuits (which prohibits you from wearing or using ''any'' other kind of equipment, except for Blasters) and the mechanism for getting you there means you can't prepare yourself for it by casting buffs before you enter. On the plus side, there's no problem with swimming (it works like flying, except you sink - slowly - if you stop), and the sharks infesting the area are weak enough that by the time you reach the Shoals, the only reason they are something of a threat is the aforementioned limitations on magic and equipment.
** The [[ElementalPlane Elemental Plane of Water]] in ''VIII''. Much closer to ordinary areas, as [[SuperNotDrowningSkills no wetsuit (with accompanying restrictions) is needed this time]] (the game doesn't explain why, though it might be because it is an elemental plane rather than a mundane underwater area) but there's a greater variety in foes, some of which have ranged attacks. The swimming mechanics are the same, though.
* ''VideoGame/DokaponKingdom'' has the Sunken Shrine, where you find the Ancient Technology to turn yourself into a Robo Knight.
* In ''VideoGame/{{Robopon}}'', if you have any fishlike Robopon you can dive under the water to an interconnected undersea labyrinth. It also has one of the best tunes in the game.
* In ''VideoGame/MarioAndLuigiSuperstarSaga'' the floor of Oho Ocean is one of the ares explored in the game.
* Blubble Lake has underwater areas in ''VideoGame/MarioAndLuigiBowsersInsideStory''.
* The Tile Pool in ''VideoGame/SuperPaperMario''.
* ''VideoGame/ChildOfLight'' has the [[TheVeryDefinitelyFinalDungeon Palace of the Sun]] under the Cynbel Sea.

[[folder:Shoot 'em Up]]
* In ''Dead Moon'' for the UsefulNotes/TurboGrafx16, the fifth stage takes place inside a mysterious lake. It ends with a BossBattle against a ''VideoGame/{{Darius}}''-like giant fish.
* ''VideoGame/{{DownWell}}'' has this for the Aquifer area.
* ''VideoGame/StarFox64'' has Aquas, which [[UnexpectedGameplayChange switches out the space fighter for a submarine]]. The original ''VideoGame/{{Star Fox|1}}'' doesn't have an underwater level per se, but Sector Y takes SpaceIsAnOcean to ridiculous levels.
** ''VideoGame/StarFoxCommand'' features the return of Aquas, plus has the BigBad's [[VeryDefinitelyFinalDungeon Very Definitely Final Base]] in the [[HollywoodAcid acidic oceans]] of [[NamesToRunAwayFromReallyFast Venom]], which the heroes can't enter without a MacGuffin.
* ''VideoGame/{{Stargunner}}'' has two levels in the first and fourth (the latter being the last) episodes that take place underwater, though you can shimmy up to the surface if you wanted to. The next seven levels after the second in the last episode, however, take place entirely under the sea; yes, you even face the FinalBoss under those conditions in the ninth and last level, albeit your ship doesn't suffer from any ill effects whatsoever underwater.

[[folder:Simulation Game]]
* One mission in ''[[VideoGame/{{Mechwarrior}} MechWarrior 2: Ghost Bear's Legacy]]'' involved attacking an enemy base underwater. You cannot customize your mech, and the 95-ton Executioner handles underwater [[InterfaceScrew about as well as you think it would]]. The visibility is very poor, making you nearly blind at anything beyond knife-fight range (but [[TheComputerIsACheatingBastard the AI can see you just fine]]). The only weapons you have are powerful but slow-moving [=PPCs=] and even slower-moving torpedoes, and you face hordes of enemy mechs. But the worst thing is that if you take a ''single'' hit to internal structure, even if it's not a critical hit, that entire section of your mech will be destroyed by flooding. So if your torso section loses its armor, it's game over. This is also ThatOneLevel.

[[folder:Sports Game]]
* One field in ''[[VideoGame/BackyardSports Backyard Baseball]]'' is the Aquadome, which is completely underwater. Yet the characters can still breathe...
* One of the mini-games in ''WesternAnimation/TinyToonAdventures: Wild and Wacky Sports'' involves Buster and his friends diving for treasures under the sea, whilst avoiding the Hammerhead Shark. Buster and his friends have [[OxygenMeter oxygen meters]] to mind to avoid drowning, which means occasionally having to rise to the surface or [[OxygenatedUnderwaterBubbles breathe in air bubbles]].

[[folder:Turn Based Strategy]]
* ''VideoGame/{{Piratez}}'': Some missions take place underwater, where you can swim in 3D and find some treasure! (Also die horribly from a Deep One's ballista, because you can't see underwater anywhere as well as actual underwater races.)
!!Entire games/works that take place Under the Sea:
[[folder:Comic Books]]
* In ''ComicBook/{{Swordquest}}'', the Waterworld realm is this combined with SlippySlideyIceWorld.

* ''Disney/TheLittleMermaidIII'' took place entirely underwater.
* ''WesternAnimation/FindingNemo'' was almost entirely set underwater, the characters being fish and all.
* ''WesternAnimation/BarbieThePearlPrincess'' takes place entirely underwater, as everyone is either a fish or a mermaid/merman.

* Creator/FrankHerbert's ''Literature/TheDragonInTheSea'' (aka ''Under Pressure'').
* Creator/FrederikPohl and Creator/JackWilliamson's ''Literature/UnderseaTrilogy''.
* Creator/JulesVerne's ''Literature/TwentyThousandLeaguesUnderTheSea'' (OlderThanRadio.)
* The latter portions of Creator/JRRTolkien's ''Literature/{{Roverandom}}'' take place here.
* [[Creator/RaymondZGallun Raymond Z. Gallun]]'s "Davey Jones' Ambassador" (1935) features an entire civilization of [[EverythingsSquishierWithCephalopods octopus-like]] sapients dwelling miles beneath the sea and using OrganicTechnology to compensate for their lack of fire and processes dependent upon high temperatures.

[[folder:Live-Action Television]]
* ''Series/SeaQuestDSV'' is basically a SpaceOpera series set underwater, with an advanced submarine exploring the ocean. [[spoiler: And then aliens take them to another planet.]]

* The song "Where Is My Mind?" by Music/ThePixies from ''Music/SurferRosa'' was inspired by scuba diving.
* ''Music/InABarUnderTheSea'' by Music/{{dEUS}} refers to being under the sea in the album title, as well as the protagonist in "Disappointed In The Sun" who dives in the sea to go to an underwater bar.

* ''Pinball/{{Barracora}}'' is set around a mysterious underwater city populated by unusual humanoid mermaids and their barracuda.
* "The Abyss" table of ''VideoGame/PsychoPinball'' takes place entirely underwater.
* ''Pinball/{{Fathom}}'' takes place beneath a deadly Bermuda lagoon.

[[folder:Tabletop Game]]
* ''TabletopGame/MermaidAdventures'' by Third Eye Games.

[[folder:Theme Parks]]
* Ride/DisneyThemeParks: The Subs ride, later ''WesternAnimation/FindingNemo'' attraction, and ''Disney/TheLittleMermaid'' dark ride.

[[folder:Video Games]]
* ''VideoGame/TheHuntForRedOctober'' games for the NES and SNES, where you play as the Red October.
* ''VideoGame/{{Aquaria}}'' is a {{Metroidvania}} indie-darling game that takes place entirely in an undersea world.
* ''VideoGame/BioShock'':
** ''VideoGame/{{BioShock|1}}'' takes place in a city at the bottom of the ocean. Amusingly, there's absolutely no swimming sections. The only time you actually travel in the ocean are the level-transitioning bathyspheres, which are automatic.
** ''VideoGame/BioShock2'' adds underwater sections, but you can't use any weapons, you have infinite air, and no enemies appear while outside of the UnderwaterCity.
* ''VideoGame/{{SOMA}}'' uses a similar element to Bioshock2, but more time is spent underwater than inside the various sites of Pathos-II, and there's the occasional hostile robot that you need to avoid. You still have infinite air, though. At one point, you even have to search a sunken ship while avoiding a teleporting monster.
* The ''VideoGame/EccoTheDolphin'' series is spent underwater. And it's completely justified, because you are playing as a dolphin. Strangely enough, it works, despite the occasional ScrappyLevel and [[ThatOneBoss Those Several Bosses]].
* ''VideoGame/EndlessOcean''
* Any ''WesternAnimation/SpongebobSquarepants'' game, obviously. However, it gets weird in the ''VideoGame/NicktoonsUnite'' series where they have to explain how humans can breathe underwater. The first game technobabbles away with [[WesternAnimation/TheAdventuresOfJimmyNeutronBoyGenius Jimmy Neutron]]'s air gums and ''Attack of the Toybots'' skirts the issue by having Bikini Bottom as a tutorial level played only as [=SpongeBob=] (though DummiedOut voice clips suggest that it would have been a regular level playable with anyone) but ''Globs of Doom'' is an offender in choosing to give no explanation.
* ''VideoGame/DiveIIHunt'', a game which involves a known character from the ''Franchise/IvaliceAlliance'', Sorbet, scuba diving under the sea and obviously, to be the best hunter.
* ''VideoGame/TheLegendaryStarfy''
* The submarine shooting game ''VideoGame/InTheHunt''. Well, except the final level, which was an enemy base.
* ''VideoGame/TheLittleMermaid'' (the LicensedGame) sets all its levels underwater. Ariel doesn't turn back into a human and walk on dry land until the ending, which ironically is the only part of the game playing "Under the Sea" aside from the title screen.
* The whole of ''VideoGame/JawsUnleashed'', excluding the trip to sea park and the tunnels of Environplus' undersea facility.
* ''VideoGame/XCOMTerrorFromTheDeep'' is set mostly on the ocean floor. It is the Seaquest to ''X-COM''[='s=] Star Trek.
* ''VideoGame/SwimIkachan'' takes place in a sea cave cut off from undersea civilization by earthquakes and run by the tyrannical Ironhead.
* ''[[VideoGame/{{Dizzy}} Bubble Dizzy]]'', in which Dizzy has to float towards the surface by jumping on rising bubbles that pop after a few seconds.
* The ''VideoGame/{{Aquanox}}'' series and their predecessor ''VideoGame/ArchimedeanDynasty'' take place [[AfterTheEnd after a nuclear conflict caused the Earth to become heavily irradiated and forced its inhabitants to thrive under the oceans]].
* ''Rescue from Atlantis''
* Most of Creator/FoxEye's games take place in underwater levels and of course has an OxygenMeter that either serves as the player character's health bar, connect itself to the health bar, or be completely separate from it. [[SignatureStyle Given the nature of these games]], [[AuthorAppeal it's to appeal to the creator's desires of underwater fantasies]]. One of their games, ''VideoGame/SacrificeGirl'', for example, takes place entirely underwater and is a combination of SurvivalHorror / {{Metroidvania}} that requires a lot of strategic traversing to avoid the many traps as well as the SuperPersistentPredator that gives chase to the player character.
* ''VideoGame/SuperSolvers'' titles ''Treasure Cove'' and ''Operation Neptune'' take place underwater. ''Treasure Cove'' is mostly the player character scuba-diving in shallow waters around an island, while ''Operation Neptune'' takes a submarine to the bottom of a trench.
* ''{{VideoGame/Subnautica}}'' is almost completely underwater, except for [[WaveMotionGun two]] [[FloatingIsland islands]] and the wreck of the Aurora.

[[folder:Western Animation]]
* Creator/VanBeurenStudios:
** Most of the Tom & Jerry cartoon "The Rocketeers" is set underwater, after Tom and Jerry's attempt to fly off on a rocket goes haywire.
** "The Haunted Ship", starring Waffles the Cat and Don the Dog, is also set almost entirely underwater.
* ''WesternAnimation/ReBoot'' has a game that was entirely underwater. It was used to introduce Andraia.
* ''WesternAnimation/{{Jabberjaw}}'' took place in an era where mankind had developed civilizations underwater.
* ''WesternAnimation/SeaPrincesses'' takes place in the underwater world of Salacia, home of numerous kingdoms named after sea creatures.