Aquatic videogame levels have been a staple of Nintendo games since Super Mario Bros., but can be seen in other games as well. Typical underwater enemies are sharks, octopuses, squid, urchins, electric eels, jellyfish (and sometimes Electric Jellyfish), clams, and some common fish like basses, rays, and mackerels with basic swimming patterns to serve as underwater goombas if the former options are a little too threatening. Expect some Underwater Ruins every now and again for decoration.
Human heroes, such as Mario, often swim fully clothed, without being weighed down or otherwise impeded — it's as if Water Is Air.
Of course, there are three problems with the underwater level: one, swimming, two, slower movement, and three, drowning. (Or not.) Down the Drain levels are especially prone to special water-based hazards and hindrances, as detailed on that page.
Compare Shark Tunnel. These can enter That One Level territory, depending on how difficult it is to swim or how small the Oxygen Meter is.
Named for the Oscar-winning song from The Little Mermaid, which coincidentally also had its own video games, appropriately taking place in this setting.
Single-Level Examples:
- In What Remains of Edith Finch, when Molly turns into a shark and chases down the seal. Also, to a lesser degree, the scene when Gregory is drowning in the bathtub, he imagines himself swimming in the sea.
- Scattered through the Caribbean Sea in Assassin's Creed IV: Black Flag are designated zones where Edward can swim in search of treasure and collectibles. He has to keep an eye on his Oxygen Meter as well as the sharks lurking around.
- Bomberman Generation: Oceans, the first part of World 2 is an entirely aquatic level set beneath the sea.
- Frogger's Journey: The Forgotten Relic: One level in Atlantis is underwater. Since Frogger can't swim, he can't go down into it until he obtains a scuba gear upgrade for OPART. Once he's down there, he has to have the scuba gear equipped to one of his action slots at all times, and the water slows him down quite a bit.
- Water levels abound in almost every The Legend of Zelda games:
- The Legend of Zelda: Ocarina of Time has its incarnation of Lake Hylia, since Link will eventually be able to dive to the bottom with the Zora Tunic (for Super Not-Drowning Skills) and the Iron Boots (to safely sink to the bottom). Beneath it is the famously difficult Water Temple, which teems with lots of water and the many ways Link has to take advantage of it: Raising or lowering its level at certain designated spots, cyclic water currents, aquatic whirlpools that act as bottomless pits, a large waterfall he has to climb through with Hookshot-based platforms, and aquatic enemies. Time after time you have to go in circles, Hookshotting every which way to collect keys, adjust water levels, and avoid enemies with indestructible shells. All of this is made more taxing by the need to pause the game constantly to switch between the Iron Boots (to sink) and the Kokiri Boots (to resurface). Then the battle with Dark Link will take a large amount of HP out of you, though it can be replaced by MP loss if you have Din's Fire, and both can 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). Finally, 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 Master Quest re-release for the Nintendo GameCube (which otherwise upped the difficulty in all levels), embedded in the Nintendo 3DS remake as a New Game Plus, makes the dungeon less difficult by providing Link the Longshot (the dungeon's flagship item) and the Boss Key much earlier, which means that the rest of the dungeon revolves around simply finding a regular key to open the door that leads to the last pathway (where the Boss Key is used to open the boss door). The Nintendo 3DS remake has the Water Temple as the only dungeon with substantial changes beyond the obvious cosmetic changes, such as color-coding the paths that you need to follow to change the water level, and making the Iron Boots a button-based item (a property borrowed from its The Wind Waker and Twilight Princess versions), eliminating the menu-switching problem.
- The Legend of Zelda: Majora's Mask has the entire ocean province known as the Great Bay (excluding the land parts that fall under Palmtree Panic or Eternal Engine instead). In particular, there's a section known as the Pinnacle Rock, in which Zora Link is guided by a seahorse (whom he previously freed) through a maze of murky water where a wrong step sends him back to the beginning (in a similar fashion to The Lost Woods in most Zelda games); it is there where Link has to find the Zora Eggs that weren't stolen by the Gerudo pirates (but are guarded by giant sea snakes), and optionally the seahorse's lover. Retrieving those Zora Eggs as well as those located in the Pirates' Fortress helps them hatch on their own and teach Link the melody that grants access to the Great Bay Temple (which is primarily Eternal Engine but also revolves about manipulating water, specifically trying to get the water to keep flowing through to a central point of the dungeon). Killing all sea snakes and reuniting the two seahorses will yield Link a Heart Piece.
- The Legend of Zelda: Oracle Games: Oracle Of Ages has a few to go around: for starters, an actual seafloor as part of the overworld, with the Zora town leading to the Womb Level inside of Jabu-Jabu. There's also the Mermaid's Cave and the Ancient Tomb, though the majority of the latter dungeon is Big Boo's Haunt, with a few touches of Lethal Lava Land and Slippy-Slidey Ice World, considering it is located on a remote island littered with whirlpools and currents that could send Link to a watery grave. The former two dungeons also have Underwater Boss Battles taking place.
- This is actually averted for The Legend of Zelda: The Wind Waker and The Legend of Zelda: 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.
- The Legend of Zelda: Twilight Princess makes diving beneath Lake Hylia possible by way of the Zora Armor (to freely swim underwater and do so with unlimited oxygen) and the Iron Boots. Beneath it is the Lakebed Temple, in which Link has to transport water from one room to another by rotating the large staircase present in the central hall. The boss is Morpheel, which is located at the absolute bottom of the dungeon (and all of Hyrule in the game).
- The Legend of Zelda: Spirit Tracks: Being the distant sequel to Wind Waker and Phantom Hourglass, the game has the Ocean Realm, which does have a large section underwater (the Ocean Floor) where Link's train can navigate without any issues (except for some enemies like the Octomines and two evil trains). However, the dungeon accessed within (the Ocean Temple), while being underwater as well, is somehow devoid of water in its rooms (even as a cosmetic element).
- The Legend of Zelda: Skyward Sword: Lake Floria, a large body of water southeast of Faron Woods that goes through a lush, colorful coral cavern where the Parella race lives. Link can use his then-recently earned Dragon Scale to swim across it while keeping an eye on his Oxygen Meter (there are bubbles that replenish it, and at one point he'll find a dry spot where a Goddess Cube can be activated). The lake is protected by Faron, who was attacked by Ghirahim and has to be healed with sacred water from Skyview Temple. After Link helps her, she'll open the path to the then-next dungeon, Ancient Cistern.
- Primal has a full-blown underwater level. Jen is given the Undine form to work and fight underwater while swimming. In an inversion of Super Drowning Skills, 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 Ōkami 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.
- Blaster Master's Stage 5, in addition to having a That One Boss, 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 how much he is looking forward to this area, and that Gunvolt has his own problems.
- DeepDive from An Untitled Story. A vertical shaft of water. Your oxygen is limited, but there are several air sources and Oxygen Meter expansions to survive.
- The Metroidvania Castlevania games often have a water level. Castlevania: Circle of the Moon's is mostly only shallow puddles of water, and Castlevania: Portrait of Ruin 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. Order of Ecclesia has two such levels.
- Alundra has the optional dungeon Fairy Pond which takes place mostly underwater and houses one of the best swords in the game in it.
- Half of the NES game Jaws is fighting sealife underwater. Other half has you sailing your boat between two ports purchasing power ups.
- Jables's Adventure has a few underwater areas, featuring fish enemies, a mermaid, and a SCUBA-diving bear.
- The Teenage Mutant Ninja Turtles game for NES had the dam stage where you had to disarm eight bombs underwater.
- A Valley Without Wind 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 Black Whales, the better.
- 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 Sunken Cavern, an Unexpected Shmup Level where Mermaid Shantae must shoot down or avoid Tinkerbats with Scuba gear, killer fishes, and underwater mines.
- Agent Armstrong has several levels where the titular hero must infiltrate the syndicate's underwater base, avoiding sea mines while planting charges to destroy the syndicate's depot ships and bathyspheres.
- Jungle Hunt has one level where the hero attacks crocodiles while swimming.
- The submarine levels in various Metal Slug 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 quite difficult until you manage to work your way around the many projectiles. Click to see the level.
- In Spider-Man and the X-Men in Arcade's Revenge, 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 Nintendo Hard in the game.
- Tomb Raider
- Tomb Raider II has several levels that are set in and around a sunken ship. It's somewhat distressing when you start the first such level, because there's no warning, and you have to figure out on-the-fly what to do next and how to find some air.
- Tomb Raider III: The Lost Artifact includes a fairly complex level set in and around an undersea research base.
- Chronicles has a section of the game set in a submarine, and the sea around it.
- Tomb Raider: Underworld 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.
- Captain America and the Avengers has Scene 3: "Challenge from the Bottom of the Sea," which is only part underwater.
- The boss fight with Porcupffer in Mario Pinball Land takes place underwater.
- The final fight in Virtua Fighter 2 was underwater, slowing your movement.
- Battle Corps has an underwater stage, which your Chicken Walker have no trouble navigating thanks to sealable air-vents. Enemies can still explode when killed, with bubbles rising to the surface when they blow.
- Call of Duty:
- The second and third games in the Modern Warfare series both have missions that start out underwater. While the one in 2 is just a glorified cutscene before it moves to action above water, the one in 3 does require some gameplay.
- The "Into the Deep" mission in Call of Duty: Ghosts.
- The "Pelagic II" and "Deep Sea" missions in Perfect Dark.
- Most of ULTRAKILL's Wrath layer is underwater or on land very close to water, with the "Sea" in this case being the River Styx but so full of corpses that it's now the Ocean Styx.
- There are a few maritime-based Fighting Fantasy adventures where at certain points, you'll end up exploring underwater areas for lengthy amounts of time.
- Seas of Blood, where you are the pirate. You get to explore the Seas of Allansia and brave various underwater hazards.
- Bloodbones, after you're forced to Walk the Plank, will have you fighting sharks, krakens, and trying to reach dry land while exploring underwater caverns.
- Stormslayer has a segment where you'll need to explore the oceans, by drinking a Magic Potion that turns you into a Fish Man.
- The climax of 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 MapleStory.
- Kingdom of Loathing 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.
- Mario Party not only has underwater minigames, but also boards themed around this setting. In all cases, the characters can breathe just fine despite being underwater (in fact, they don't even swim):
- Mario Party:
- In the minigame Deep Sea Divers, the characters are split into two teams. In each team, one player dives underwater to reach a treasure chest and tie it with a string to the boat where the other character awaits; next, the character on the boat has to move around the surface to pull the chest into the surface to open it and claim the coins within. The bigger chests are heavier, taking longer to carry to the surface.
- In the minigame Treasure Divers, players have to swim underwater to grab chests and take them to the surface to claim their coins. Unlike in Deep Sea Divers, the players are on their own, and must avoid the aquatic enemies lurking in the area (namely Bloopers and Sushi); if a character is hit while carrying a chest, they'll end up releasing it, forcing them to grab the chest once again.
- Mario Party 3: Deep Bloober Sea is a lush, lively underwater landscape inhabited by luminescent flora, seahorses and jellyfish in the northern half; and by standard Cheep Cheeps and Bloopers in the southern half (the two halves of the board are partially divided by a rift in the middle ground). A very large anglerfish lies in the board's northwest corner; if a player lands on any of the nearby Event Spaces, the anglerfish will try to swallow them (which can be prevented by repeatedly tapping A); if the anglerfish succeeds, then the player will be launched to a direction pointed by a red arrow (placed where the anglerfish's alluring lamp would be).
- Mario Party 5: Undersea Dream is a colorful underwater biome divided in two major halves: The west side featuring a pearlclamp, a seashell and a large sunken ship; and the east side that constitutes a large network of coral reefs and houses a friendly whale who can shoot a character into a tile close to the current Star for sale (whether the character lands in front of it or behind is chosen randomly). Landing on the Event Space in the ship summons a dolphin that gives the player a ride to another part of the board.
- Mario Party 7: The minigame Be My Chum has three characters swimming within the area of a coral reef next to a stranded submarine, while the fourth player is in a small cove in the surface using the Mic to summon several enemies (most of them aquatic) to eliminate the rivals upon contact. The solo player wins if all three rivals are defeated, but the trio will win if at least one of them resists during 30 seconds.
- Mario Party 9: Blooper Beach has a few segments where the players go underwater.
- The Sunken Treasure Captain Event places the players on diving platforms at the ocean floor, where they have each collected a cluster of Mini Stars. In order to keep them, players must move enough spaces to return to the surface within three Dice Block rolls. There are three Dice Blocks; a Normal Dice Block, a 1-2-3 Block, and a 4-5-6 Block, and the Captain chooses the order in which players will roll the Blocks. Adding extra tension are Unlucky Spaces that cause anyone who lands on them to be attacked by Fishbones that will take five Mini-Stars away. Any players that reach the surface will get to keep the Mini-Stars they held onto.
- The Cheep Cheep Shot boss minigame has the players swimming underwater to take on a giant Cheep Cheep that swims around and tries to tackle the players. Along the way, players have to collect green Koopa Shells before aiming and firing them at the Cheep Cheep to score points.
- Mario Party 10:
- Whimsical Waters is a board taking place in an underwater lagoon, with Team Mario using a submarine to navigate, while Bowser has to swim through. Along the way, sights include houses made from giant spiral shells, coral reefs, and sunken ships. The characters periodically encounter a Dragoneel that offers them chances to pick a sunken treasure box for a chance to win valuable items. The characters' voices are also distorted, to reflect that they're speaking in an underwater setting.
- Blooper Blastoff puts players in Blooper-shaped submarines at the ocean floor. The objective is to be the first to use the submarine's thruster to propel yourself to the surface, all the while avoiding Torpedo Teds, as well as water currents coming out of Warp Pipes.
- Mario Party:
- Sonic Shuffle has this in Emerald Coast. Sonic and his friends have to pay attention to their oxygen meters while underwater, as the number decreases with every turn taken. If the meter reaches 0, they will drown and lose a turn. Landing on bubble spaces refills the oxygen meter.
- Banjo-Tooie: Jolly Roger's Lagoon starts out as a Gangplank Galleon level, but once Mumbo enchants the water, Banjo and Kazooie will be able to swim indefinitely, allowing them to explore a gigantic aquatic world, with ruins from Atlantis, sunken ships and a mechanical fish they can enter (it is there where they find Jolly Roger's lover, Merry Maggie Malpass, previously swallowed by the fish but alive and unharmed).
- Two levels in Crash Bandicoot 3: Warped have Crash explore underwater areas. He's using a diving gear in them because he's otherwise unable to survive underwater (in other levels, water drowns him instantly).
- Donkey Kong has several examples. Given the Kongs' species, none of them should be able to swim in the first place:
- Donkey Kong Country: Most worlds in the franchise's platform games, starting with this one, have aquatic levels where the playable Kongs have to swim while avoiding several Aquatic Mooks, though they can also summon Enguarde so they can traverse the waters more swiftly. The levels have a maze-like design, so it's easy to get lost unless the player pays attention to where they're going.
- Donkey Kong Country 2: Diddy's Kong Quest has Glimmer's Galleon, with almost every other water level being a mix of land and water gameplay.
- Donkey Kong Country 3: Dixie Kong's Double Trouble!: Cotton-Top Cove is set in a coral reef, and is full of lakes and waterfalls. Some levels take place underwater (one of which is notable for having the Kongs feed a predatory fish with other enemies so it doesn't chew them instead), while others are in front of the waterfalls and are climbed by using special blast barrels (rocket-style barrels with jets in one case, and Kong-guided barrels in another). The boss is Squirt, a monster in a rocky wall behind a waterfall that attacks by spitting a stream of water that aims to push Ellie into the pits below.
- Donkey Kong 64: The (huge) underwater portions of Gloomy Galleon, in which Lanky can transform into Enguarde the Swordfish to swim more efficiently. The sunken ships are explorable, though they're so dark that they need light from a nearby creature. There's also a large treasure chest Tiny can access by shrinking and entering through the keyhole; getting there is necessary to retrieve some pearls for a mermaid.
- Donkey Kong Jungle Beat was the first game Donkey can fight off enemies underwater without any animal buddies.
- Donkey Kong Country Returns surprisingly lacks any underwater levels (the only aquatic levels overall are those of World 2, which is Palmtree Panic), but Donkey Kong Country: Tropical Freeze has a whole world of nothing but water levels. Features include sunken mechanisms that can be activated by passing through luminous buttons, an underwater maze where the Kongs have to open chest with color-coded keys in a specific sequence, a giant squid they have to run away from (which also appeared in the previous game), and underwater currents that make navigation difficult.
- This setting is a staple of the Super Mario Bros. series:
- Super Mario Bros. is the first to feature a swimming Mario, doing so in the second level of World 2. Notably, the Minus World is also an underwater level, and it cannot be completed. Super Mario Bros.: The Lost Levels waits until World 3-2.
- Super Mario Bros. 2 is the only mainline game in the series to show a notable aversion of the trope, since Mario and his friends are unable to swim in the waters of Subcon. There are still aquatic levels (Worlds 3-1 and 5-1), but in them they have to avoid falling to the bottom of the (very tall in the former, very wide in the latter) waterfall.
- Super Mario Bros. 3 has a frog suit that allows Mario or Luigi to swim faster. Makes World 3, a water-based level, much easier.
- Super Mario Land has the last level of Muda Kingdom. Mario uses the Marine Pop (a submarine) to navigate through what's now an underwater shmup level.
- Underwater levels are rare in Super Mario World, though whenever Mario or Luigi enter one they can continue riding Yoshi if he's riding him.
- Super Mario Land 2: 6 Golden Coins has two such areas: the Hippo Zone (an interlude level which can lead to the Space Zone), and the Turtle Zone (a proper aquatic world).
- The occasional water level is found in all New Super Mario Bros. games, especially in each installment's designated Palmtree Panic world. In two of the games, the Penguin Suit is present for Mario and his friends to swim smoothly underwater, and its ice properties allow them to freeze enemies as well.
- This is one of the settings present in Super Mario Maker and Super Mario Maker 2, and is available in all game styles. In the latter game, in Night mode, the whole level is pitch black except for the characters' immediate surroundings and some luminous items and enemies (grabbing a Super Star will temporarily illuminate much of the screen).
- "Lots O'Fish" and "Lots O'Jellyfish" on page five of Yoshi's Story. The Page itself is known as "Ocean", but the other two levels in it are above-ground Palm Tree Panic areas.
- Super Mario 64 features three worlds of this kind (Jolly Roger's Bay, Dire Dire Docks and Wet-Dry World), and is the first to include an Oxygen Meter (and water with magical healing properties), since your health meter and air meter are the same. The water's level can be adjusted in Wet-Dry World.
- Super Mario Sunshine 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.
- Super Mario Galaxy has a whole seven worlds/areas with aspects of this setting (including two of the fifteen major worlds, Beach Bowl Galaxy and Sea Slide Galaxy), with the usual water based enemies that go with it. Super Mario Galaxy 2 has Cosmic Cove Galaxy and Slimy Spring Galaxy.
- Super Mario 3D Land and its sequel Super Mario 3D World have the occasional underwater stage, with Land being the first 3D Mario game to not have an oxygen meter.
- Super Mario Odyssey has the underwater body of Seaside Kingdom and nearly all of Lake Kingdom. In both levels, Mario can possess Cheep Cheeps thanks to Cappy, allowing him to swim indefinitely without having to worry about oxygen.
- Wario Land has had a few of these settings.
- The first game, Wario Land: Super Mario Land 3 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).
- Wario Land: Shake It! has various underwater submarine shooter type levels (Wavy Waters and Creep Blue Sea being examples).
- Most Mega Man games have one of these; while the blue bomber didn't swim except in Mega Man 8 (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, not that it was of any help. Mega Man Star Force 2 has Mess Cove.
- Rayman:
- Rayman 2: The Great Escape has a level with some sequences under the sea. In one of them, you have to free a whale that will guide you and leave air bubbles for you (which will be eaten by piranhas if you're not fast enough to catch them).
- Rayman 3: Hoodlum Havoc has another level under the sea, culminating in the Mechasquid boss encounter.
- Rayman Origins 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.
- Act One of Planet Undertow from Ristar involves Ristar swimming underwater and battling various sea creatures. Act Two of the same stage has some Underwater Ruins elements, and the boss of Act Three is Ohsat, a hammerhead shark.
- Sonic the Hedgehog:
- While many games contain water, Sonic 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 Hydrocity and later games, he can skip the whole swimming thing and just run across the water.
- As opposed to Sonic's Super Drowning Skills, Tails, Knuckles and Rouge can swim, and Knux can even get an artificial breather in Sonic Adventure 2 to dive as long as he wants (and walk on the floor).
- In Sonic Advance 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 nightmares thanks to the drowning music.
- Some actual examples include the Underwater Ruins levels such as Hydrocity, but Coral Cave in Sonic Rush Adventure mixes it up with Underground Level and Minecart Madness.
- Labyrinth Zone in the original Sonic the Hedgehog. One Game Mod of it, Sonic the Hedgehog Megamix, 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.
- Sonic the Hedgehog 2:
- Aquatic Ruin from the Genesis version, of the Underwater Ruins 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 increases the difficulty.
- Aqua Lake in the Game Gear and Sega Master System versions. Unlike later games, Sonic doesn't run on the water's surface, instead bouncing over it like a skimming stone.
- Wild Water Ways in SegaSonic the Hedgehog.
- Tidal Tempest in Sonic CD.
- Aqua Planet in Sonic Chaos 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.
- Hydrocity from Sonic the Hedgehog 3, also of the Underwater Ruins 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 Plant in Sonic Triple Trouble which borders on being Down the Drain as you spend almost the entire second act underwater.
- The Labyrinth of the Sea from Sonic Labyrinth.
- Blue Marine in Sonic Blast.
- Sonic Adventure has this mainly in Sonic's Lost World, but almost all the Big stages feature water. Makes sense, considering he's fishing.
- Aquatic Relix Zone in Sonic Pocket Adventure.
- Dry Lagoon and Aquatic Mine from Sonic Adventure 2 combine this with Underwater Ruins and Ruins for Ruins' Sake. 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 Sonic Advance Trilogy gets these as well. Ice Mountain in 1 and Twinkle Snow in 3 are both combined with Slippy-Slidey Ice World (Dimps likes this combination). Ocean Base in 3 is an Underwater Base, 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.
- Water Palace from Sonic Rush.
- Rush Adventure has Coral Cave that was mentioned above, but it also has Pirates Island, another Underwater Ruins level, only with more anchors, dolphins, and weaponry. In addition, among the many vehicles that Sonic and crew use to get around the world map is a submarine called the Deep Typhoon.
- Lost Labyrinth from Sonic the Hedgehog 4 Episode 1 is this mixed with Underwater Ruins. There is also Sylvania Castle (same sort of thing) and White Park's third act (the rest is Slippy-Slidey Ice World and Amusement Park) in Episode 2.
- Aquarium Park Zone from Sonic Colors.
- Sonic Generations has some. The HD version features Chemical Plant, which is upgraded to become somewhat more watery than the original's, complete with water rising sections. It also has Seaside Hill, which wasn't a water level in the first place but was retooled to be Underwater Ruins for Classic Sonic. The 3DS version features the reappearance of Water Palace.
- Metroid:
- A recurring powerup in the series is the Gravity Suit, a purple-colored armor that allows Samus to walk underwater while negating the damping effects of water. It is helpful in the underwater areas of Maridia in Super Metroid, Sector 4 (AQA) in Metroid Fusion, the Sunken Frigate in Metroid Prime, the flooded rooms of Area 5 in Metroid: Samus Returns, and Burenia in Metroid Dread. Another feature is that the suit reduces the damage received from enemies.
- Torvus Undertemple in Metroid Prime 2: Echoes is a flooded facility. In absence of the Gravity Suit in this game, Samus uses the Gravity Boost (an add-on for the Dark Suit that allows Samus to hover underwater temporarily) instead to move better. Interestingly, though the room where the powerup is found is guarded by Alpha Blogg, the battle against it only starts after Samus claims it.
- Metroid: Other M doesn't have a dedicated water sector, but Sector 1 and Sector 3 have significant portions of underwater sections. The oddity is that you have the Gravity Suit that allows you to move underwater unhindered, but it isn't authorised until extremely late into the game.
- Bug!:
- The original game has Quaria, which serves as the fourth world. This world is filled with many fish enemies, fire-spitting moray eels (yes, underwater), crabs, starfish and clams. Oh, and the obligatory giant octopus/squid, which served as the boss.
- Bug Too! has "Swatterworld", which serves as the fifth world. This world is filled with enemies with stealth puns, such as Sea Monkeys (a cross between a monkey and a fish), hammerhead sharks (a shark with a hammer on its head), and saw-nosed sharks (a shark a with chainsaw attached to its face).
- Athena has the World of Sea, where Athena can use a necklace to transform herself into a mermaid.
- In Commander Keen Episode 4: Secret of the Oracle, the Well of Wishes is an underwater level where you can't jump or shoot, only swim. Its waters are home to numerous mines and the one and only Dopefish. Water in other places simply kills you at a touch.
- Spyro the Dragon: Spyro had Super Drowning Skills, so the first game doesn't use water. However, subsequent games give him the ability to swim and send him to levels that are mainly water.
- Little Nemo: The Dream Master has the fourth level, Night Sea.
- 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 Sly Spy, the protagonist dons a scuba suit to go underwater for the fourth and seventh stages, which feature Thunderball-style harpoon combat.
- 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.
- Barney's Hide & Seek Game on the Sega Genesis has the fourth level which Barney himself says is "Under the Sea".
- Kirby:
- Kirby 64: The Crystal Shards: The latter half of Aqua Star takes place in underwater caves and canyons.
- Kirby & the Amazing Mirror: Area 6, Olive Ocean, has large sections where Kirby must swim against the currents to reach the area's Underwater Boss Battle.
- Overload Ocean in Kirby: Planet Robobot which is also industrialized given the game's theme.
- The Southern Resort in Klonoa 2: Dream Champ Tournament features 3 of these levels (one of which is also an Auto-Scrolling Level), and since Klonoa can't swim, he's loaned a mechanized diving suit that lets him traverse them. While he can jump higher and farther underwater, he can't run as fast.
- Tiny Toon Adventures games:
- In the 1991 NES Licensed Game 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 play as Plucky, due to his enhanced swimming abilities.
- Several levels in 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 summoning Little Beeper.
- The 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 boss of the stage is Scratchy in a submarine.
- The sixth level of The Flintstones: The Rescue Of Dino & Hoppy 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 Snake Pass is set mostly underwater.
- In Theta vs Pi 7 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.
- The 4th stage of GRIS is generally water-thamed, and a large part of it is spent by swimming underwater.
- The Inlet from Deep Duck Trouble, where Donald Duck dons scuba gear to seek out the Golden Fang.
- In the Pinocchio Licensed Game, the sixth level takes place on the bottom of the sea, where Pinocchio searches for Monstro the Whale. Collecting clams keeps Pinocchio weighted to the sea floor, but they only last for a short time, so it's important to collect as many as possible. Pinocchio can also use sea anemones and manta rays to get across dangerous areas.
- Looney Tunes games:
- In Looney Tunes (1992), the second half of Stage 1 involves Daffy Duck diving underwater to recover the sunken treasure, battling sea creatures, a bathing suit-clad Yosemite Sam, and a mechanical anglerfish that serves as the end-of-stage boss. Daffy also cannot drown the entire time he's underwater.
- In Daffy Duck: The Marvin Missions, the second level, "20,000 Martians Under the Sea", takes place on Planet Aquarion-4, a majority of which is underwater.
- In Gem Smashers, the first world, Poseidonia, takes place underwater. The boss of the stage is an anglerfish.
- Repton Around the World includes the Oceans scenario, considered to be the game's most difficult.
- Outer Wilds has this under the ocean planet Giant's Deep, once you manage to get through the currents.
- Super Indie Karts 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.
- Snowboard Kids 2 has Turtle Islane (no relation to the 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.
- Mario Kart:
- Mario Kart 7: Ever since this game introduced underwater racing as a mechanic, many aquatic courses are either completely this theme, such as Cheep Cheep Lagoon in Mushroom Cup; become this theme as a returning course, such as Koopa Cape in Lightning Cup going from Shark Tunnel to this; or have this theme mixed with another theme, such as Wario Shipyard in Star Cup mixing Gangplank Galleon with it.
- Mario Kart 8: Dolphin Shoals in Star Cup takes place in a pristine river filled with colorful coral reefs and inhabited by Cheep Cheeps, friendly dolphins and a giant Unagi. There's also Water Park in Mushroom Cup, an Amusement Park based on aquatic attractions where drivers go through many flooded parts. Some of the retro courses also receive underwater segments like in Mario Kart 7, such as DS Cheep Cheep Beach, GCN Sherbet Land, and DS Wario Stadium (and more of them were added in 8 Deluxe with its downloadable Expansion Pack).
- Mario Kart Tour: Piranha Plant Cove is an archipelago featuring underwater ruins, and the drivers go through them across the course's three variants (the third one is unique for taking place entirely underwater, a first for the series).
- Bikini Bottom Blowout from Nicktoons Racing, which is based on Spongebob Squarepants.
- Kingdom Hearts: Atlantica in the first game, which is a world based on The Little Mermaid, the Trope Namer. Unfortunately, many players didn't like the level because of its unintuitive control scheme, so the developers attempted to fix it for Kingdom Hearts II by replacing it with a rhythm game (whose fan reception was even worse). It's absent altogether in Kingdom Hearts III. However, "The Caribbean" does have some underwater segments on various islands, including a boss fight with the Lightning Angler that must be completed to open a new path.
- XenoGears: Sargasso Point is an underwater cavern the party travels to with their Gears which serves as the hiding place for the final gate blocking the path to Solaris.
- Final Fantasy:
- Final Fantasy VI has the Serpent Trench, in which 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 Inexplicable Treasure Chests.
- There is no specific underwater level in Final Fantasy X 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 Marvel Ultimate Alliance The difficulty of operating underwater is technobabbled 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.
- Mega Man Battle Network:
- Mega Man Battle Network 4: In Aqua Man's chapter, Mega Man has to traverse through the net when it becomes flooded, requiring the use of an Oxygen Meter.
- Mega Man Battle Network 5: The Ship Level has underwater segments with a limited air meter while diving. Mega Man can recover air by touching bubbles or walking up ramps leading back to the surface, while some obstacles will drain the meter faster. An empty air meter thankfully doesn't lead to any immediately dire consequences, just constant Damage Over Time while out of combat.
- The final quest on Manaan in Star Wars: Knights of the Old Republic 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 That One Level.
- Wizardry 8 has the Bayjin Shallows and Mount Gigas Water Caves. Despite preventing fire magic from working, the water areas are not the resident Scrappy Level. That title is reserved for Bayjin, the Palmtree Panic level you're trekking underwater to get to.
- In Pokémon Ruby and Sapphire, 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 Pokémon Black and White, 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 Fossil Fighters. The player walks fully-clothed along the bottom of the ocean, looking for fossils. There are also sharks when the area is first unlocked.
- 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 kissing robotic mermen who breathe the air into them.
- Appears in some games in the Might and Magic 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 Elemental Plane of Water in VIII. Much closer to ordinary areas, as 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.
- Dokapon Kingdom has the Sunken Shrine, where you find the Ancient Technology to turn yourself into a Robo Knight.
- In 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.
- Super Mario Bros.:
- In Mario & Luigi: Superstar Saga the floor of Oho Ocean is one of the ares explored in the game.
- Blubble Lake has underwater areas in Mario & Luigi: Bowser's Inside Story.
- The Tile Pool in Super Paper Mario.
- The Witcher 3: Wild Hunt has various bodies of water that you can dive in to finish a quest or search for loot.
- Child of Light has the Palace of the Sun under the Cynbel Sea.
- Etrian Odyssey III: The Drowned City: The Undersea Grotto serves as the game's second dungeon. The player's characters can breathe normally, so oxygen is not an issue. However, they do have to deal with one-way currents, both when navigating through passageways and when avoiding the local FOE; at one point, they can place a special orb in a certain spot to turn off the currents. It returns in Etrian Odyssey Nexus as a Nostalgia Level, retaining many of its original features (as well as the same boss). However, it also adds a special Fetch Quest where the character has to look for certain sunken scrolls that document the history of Lemuria. In fact, due to not being able to turn off the sea currents until reaching a certain point in the third floor, they have to backtrack to the second floor to get a previously-inaccessible scroll.
- Monster Hunter:
- Monster Hunter 3 (Tri) has the northern zones of Deserted Island (where monsters like Royal Ludroth, Gobul and Lagiacrus can be found and fought), as well as the boss-dedicated Underwater Ruins (home of Ceadeus, the Final Boss of the single-player campaign). The game's expanded version, 3 Ultimate, adds the Tainted Sea (where the multiplayer Final Boss, Dire Miralis, lies), as well as new aquatic monsters for the existing areas (Goldbeard Ceadeus, Ivory and Abyssal Lagiacrus, and series veterans Plesioth and Green Plesioth). While the Deserted Island appears in Portable 3rd and Generations as well, it averts this trope in them because it's no longer possible to swim due to a lack of underwater gameplay (for this same reason, the Flooded Forest appears dry in the former game as well as Monster Hunter: Rise, with the justification that it's summer).
- Monster Hunter: World has a very interesting example in the Coral Highlands, a region of the New World that looks like an underwater level, but without the water. The landmasses in the Coral Highlands resemble deep-sea coral, and jellyfish-like lifeforms can be seen drifting through the air.
- In Dead Moon for the TurboGrafx-16, the fifth stage takes place inside a mysterious lake. It ends with a Boss Battle against a Darius-like giant fish.
- The second world of Dragon Blaze 2000 is set entirely underwater, and filled with aquatic-based enemies including sharks, jellyfishes, squids, and enemy submarines whose designs are based on marine life.
- DownWell has this for the Aquifer area.
- Star Fox 64 has Aquas, which switches out the space fighter for a submarine. The original Star Fox doesn't have an underwater level per se, but Sector Y takes Space Is an Ocean to ridiculous levels. Star Fox Command features the return of Aquas, plus has the Big Bad's Very Definitely Final Base in the acidic oceans of Venom, which the heroes can't enter without a MacGuffin.
- 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 Final Boss under those conditions in the ninth and last level, albeit your ship doesn't suffer from any ill effects whatsoever underwater.
- One mission in MechWarrior 2: Ghost Bear's Legacy involved attacking an enemy base underwater. You cannot customize your mech, and the 95-ton Executioner handles underwater about as well as you think it would. The visibility is very poor, making you nearly blind at anything beyond knife-fight range (but 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 That One Level.
- One field in Backyard Baseball is the Aquadome, which is completely underwater. Yet the characters can still breathe...
- Mario Golf: World Tour has an undersea golf course, of all things. It's not domed or anything, the characters actually golf underwater.
- One of the mini-games in Tiny Toon Adventures: 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 oxygen meters to mind to avoid drowning, which means occasionally having to rise to the surface or breathe in air bubbles.
- 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:
- Doraemon
- Most of Doraemon: Nobita and the Castle of the Undersea Devil takes place under the Atlantic Ocean, which Nobita and friends can survive in thanks to Doraemon's gadgets. Lampshaded when Shizuka asks if she can take a bath (being a habit of hers), Doraemon reminds her that they're underwater.
- Doraemon: Nobita's Great Battle of the Mermaid King have the gang going underwater again, this time thanks to gaining mermaid forms, with most of their adventure happening beneath the oceans.
- Season 16 of Happy Heroes takes place in the ocean, where the Supermen are sent to protect the mermaid princess Ling Er, who is involved in a prophecy about her turning into sea foam, causing the ocean and the planet to enter a crisis.
- The Pleasant Goat and Big Big Wolf season Adventures in the Sea is about the goats going underwater to find the pieces of the Ocean Star and put it back together.
- In Swordquest, the Waterworld realm is this combined with Slippy-Slidey Ice World.
- The bulk of The Little Mermaid takes place underwater.
- The Little Mermaid III: Ariel's Beginning: Save for the prologue sequence that highlights Queen Athena's death, and a brief moment towards the end, there is not a single scene in the movie that plays out on land.
- Finding Nemo was almost entirely set underwater, the characters being fish and all.
- Barbie: The Pearl Princess takes place entirely underwater, as everyone is either a fish or a mermaid/merman.
- The Fighting Fantasy gamebook Demons of the Deep is set almost entirely underwater. You gain a set of magical gills right at the start of the adventure by landing on a magic pentagram which can last for twelve hours.
- Frank Herbert's The Dragon In The Sea (aka Under Pressure).
- Frederik Pohl and Jack Williamson's Undersea Trilogy.
- Jules Verne's 20,000 Leagues Under the Sea (Older Than Radio.)
- The latter portions of J. R. R. Tolkien's Roverandom take place here.
- Raymond Z. Gallun's "Davey Jones' Ambassador" (1935) features an entire civilization of octopus-like sapients dwelling miles beneath the sea and using Organic Technology to compensate for their lack of fire and processes dependent upon high temperatures.
- SeaQuest DSV is basically a Space Opera series set underwater, with an advanced submarine exploring the ocean. And then aliens take them to another planet.
- The song "Where Is My Mind?" by The Pixies from Surfer Rosa was inspired by scuba diving.
- In a Bar, Under the Sea by 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.
- Barracora is set around a mysterious underwater city populated by unusual humanoid mermaids and their barracuda.
- "The Abyss" table of Psycho Pinball takes place entirely underwater.
- Fathom takes place beneath a deadly Bermuda lagoon.
- Mermaid Adventures by Third Eye Games.
- BIONICLE: The 2007 Story Arc took place completely underwater, as the Macguffin - the Mask Of Life - had sunk there after the events of the previous storyline; the Toa Inika were expecting to go down, find it, and come back; instead they found an entire Sunken City of stranded Matoran, a bevy of escaped criminals who'd been mutated into sea-creature like forms and led by six ancient warlords, said criminals' Back from the Dead prison warden, and the previously presumed-dead Makuta. Unlike most examples of this trope, the Marhi Nui arc really played up the terror and the alienness of the ocean floor.
- Disney Theme Parks: The Subs ride, later Finding Nemo attraction, and The Little Mermaid dark ride.
- The Hunt for Red October games for the NES and SNES, where you play as the Red October.
- Aquaria is a Metroidvania indie-darling game that takes place entirely in an undersea world.
- BioShock:
- BioShock 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.
- BioShock 2 adds underwater sections, but you can't use any weapons, you have infinite air, and no enemies appear while outside of the Underwater City.
- Death in the Water (and it's sequel) is an underwater FPS, with your enemies being hostile aquatic creatures from sharks to lionfishes to octopuses. The second game ends with you fighting a Krakken-like boss.
- Dive II Hunt, a game which involves a known character from the Ivalice Alliance, Sorbet, scuba diving under the sea and obviously, to be the best hunter.
- The Ecco the Dolphin series is spent underwater. And it's completely justified, because you are playing as a dolphin. Strangely enough, it works, despite the occasional Scrappy Level and Those Several Bosses.
- Endless Ocean
- flOw: Implied, by the internal names for its enemies all being named after fish, and the watery blue environment.
- Any Spongebob Squarepants game, obviously. However, it gets weird in the Nicktoons Unite! series where they have to explain how humans can breathe underwater. The first game technobabbles away with 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 Dummied Out 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.
- The Legendary Starfy
- The submarine shooting game In the Hunt. Well, except the final level, which was an enemy base.
- The Little Mermaid (the Licensed Game) 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 Jaws Unleashed, excluding the trip to sea park and the tunnels of Environplus' undersea facility.
- SOMA 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.
- Swim, Ikachan! takes place in a sea cave cut off from undersea civilization by earthquakes and run by the tyrannical Ironhead.
- Bubble Dizzy, in which Dizzy has to float towards the surface by jumping on rising bubbles that pop after a few seconds.
- The Aquanox series and their predecessor Archimedean Dynasty take place after a nuclear conflict caused the Earth to become heavily irradiated and forced its inhabitants to thrive under the oceans.
- Most of Fox Eye's games take place in underwater levels and of course has an Oxygen Meter that either serves as the player character's health bar, connect itself to the health bar, or be completely separate from it. Given the nature of these games, it's to appeal to the creator's desires of underwater fantasies. One of their games, Sacrifice Girl, for example, takes place entirely underwater and is a combination of Survival Horror / Metroidvania that requires a lot of strategic traversing to avoid the many traps as well as the Super-Persistent Predator that gives chase to the player character.
- Super Solvers 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.
- Subnautica is almost completely underwater, except for two islands and the wreck of the Aurora.
- XCOM Terror From The Deep is set mostly on the ocean floor. It is the Seaquest to X-COM's Star Trek.
- Rock Bottom by TomSka.
- Polinices is a Speculative Biology project that focuses on the many Starfish Aliens in the big global ocean of the eponymous planet. Fittingly, many of the lifeforms are asymmetrical and/or colonial organisms somewhat similar to real life undersea life on Earth such as hydrozoans and coral. While Polinices has an above-water supercontinent, intense solar radiation leaves it uninhabitable.
- NOC +10: When coordinates are given, they reveal that the videos are being broadcast from within the Mariana Trench, revealing this series to be the result of experiments in an undersea laboratory.
- Van Beuren Studios:
- 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.
- ReBoot has a game that was entirely underwater. It was used to introduce Andraia.
- Jabberjaw took place in an era where mankind had developed civilizations underwater.
- Sea Princesses takes place in the underwater world of Salacia, home of numerous kingdoms named after sea creatures.
- SpongeBob SquarePants takes place in the fictional underwater city of Bikini Bottom. This is supported by the main cast being aquatic animals (minus Sandy Cheeks, a squirrel from Texas who wears a bulky diving suit outside of her dome).