Walk, Don't Swim

"Captain Barbossa: Gents... take a walk!

Captain Jack: ...Not to the boats?"

- Pirates of the Caribbean

A character is too dense to have any buoyancy, so they deal with bodies of water by walking across the bottom rather than swimming. This is a common strategy with characters who can breathe underwater, or creatures like zombies, golems, or robots who don't need to breathe at all. Of course, immunity to drowning isn't strictly necessary to walk underwater, but it helps.

Often happens in video games, where this saves the programmers from having to code for swimming behavior, while averting Super Drowning Skills. Just make the character move slower and jump higher, give them an Oxygen Meter, and voila! underwater physics.

If this is done by Fish People who should be capable of swimming, for no reason other than ignorance of the third dimension, see Water Is Air. See Walk On Water for an even more impressive version.

Anime & Manga

 * Referenced in Ghost in the Shell with regard to the Major's hobby of SCUBA diving. Batou comments that he's never heard of a diving cyborg before, and for good reason: a buoyancy compensator failure would result in guaranteed death. Cybernetic bodies are far too heavy to permit unassisted swimming at all, and a cyborg stuck on the bottom thus would run out of oxygen long before he/she would be able to walk back to shore.
 * Ikaros did this in Sora no Otoshimono.

Comicbooks

 * In X-Men, this is Juggernaut's default way of crossing water.
 * Colossus would do this too, as his "organic steel" body doesn't need to breathe. As he walked away from a plane crash on one occasion, things got troublesome when the island the team was headed to disabled all mutant powers...
 * In the Astro City "Tarnished Angel" story arc, the Reformed but Rejected Chrome Champion Steeljack falls into the river. He manages to hyperventilate himself and walks across the riverbed to shore.
 * Clumsy Carp can do this at will (and apparently hold his breath indefinitely) in BC
 * In Concrete, Ron Lithgow, the title character has noted that if he fell into a deep and large body of water, he would sink to the bottom without a big floatation device and/or special swimming equipment and his only chance of survival would be to walk on the bottom to a swallow area before he drowns. Fortunately, he can hold his breath for an hour, so he has more time to do that than any human.

Film - Live Action

 * Pirates of the Caribbean: The Curse of the Black Pearl: The undead pirates walk along the ocean floor to reach Commodore Norrington's ships undetected.
 * Earlier in the film, Jack and Will commandeer a skiff, turn it upside down and trap air inside it, and walk along the bottom of the harbor.
 * This part was busted.
 * In The Crimson Pirate, Captain Vallo, his sidekick Ojo and The Professor use the upside-down trick to walk to shore after being chained to a dingy without rows or sails.
 * Early in Highlander, Connor is thrown into a lake by Ramirez. He (Connor) can't swim, but can't die, either, so this happens.
 * The zombies from Land of the Dead.
 * Data does this in Star Trek Insurrection.
 * Apparently, a deleted scene from Friday the 13 th Part VIII: Jason Takes Manhattan would've shown Jason doing this.

Literature

 * Golems in the Discworld, being automata, can do this. When Boxed Crook Moist von Lipwig is assigned one as his parole officer in Going Postal, he is reminded that even fleeing to a different continent would not help him, as it would be able to walk any body of water eventually. In addition, said parole officer previously spent several decades at the bottom of a well manning a pump, and another golem spent several thousand years at the bottom of the ocean before it was recovered, but neither of them did much walking in that time.
 * Zombies do the same, as Windle Poons just walks ashore after attempting to drown himself, and Reg Shoe contemplates walking all the way back to Ankh-Morpork along the bottom of the sea if their ship is sunk.
 * Larry Niven and Steven Barnes' novel Dream Park. When the party escapes pursuing zombies by taking a small boat, the zombies walk into the water after them. The players forget that zombies don't need to breathe, and the zombies walk along the bottom and eventually grab one of the party members and drag her underwater.
 * Mentioned in both The Zombie Survival Guide and World War Z as a reason to be careful around water during a zombie outbreak. It's also a reason to be vigilant after an outbreak, because you never know when a zombie might stumble out of the ocean and spark a new infection.
 * In Caves of Ice, a force of Necrons manage to wade through several levels worth of caves (of ice) that have been flooded with pure promethium (i.e., tank and flamethrower fuel). This does not help them in the slightest when it explodes.
 * Dortmunder and Kelp plan to do this in an attempt to retrieve a cache of stolen cash from under a lake in Drowned Hopes by Donald Westlake. It fails as they discover the inherent bouyancy of the human body.

Live Action TV

 * In one Gilligans Island~ episode, an experimental robot lands on the island. He can't swim due to his weight, but the castaways discover that he's completely watertight, so they program him to walk to civilization and carry their message of rescue. The robot manages to complete the long trek, but fails to deliver the message because the lucky rabbit's foot Gilligan placed inside the robot played havoc with the magnetic tape on which the castaways had recorded their message.
 * One Terminator: The Sarah Connor Chronicles episode revealed that terminators are too dense to swim. It's not as much of a Weaksauce Weakness as it seems, because it's only useful if the terminator doesn't have a gun and you are near deep water, and even then you only gain the time it takes for the terminator to sink to the bottom and walk out.
 * In one episode of Star Trek the Next Generation when they think android officer Data has died, his friend Geordi remenisces about a time when the engineering crew went swimming in a planet's ocean, and Data tried to dive in and join them. whereupon his metal body immediately sank to the bottom and he had to walk several miles back to land.

Toys

 * Many videos and advertisements for Bionicle's Mahri Nui storyline showed the characters walking around on the ocean floor, however, the books, comics and serials showed them swimming.

Tabletop Games

 * Paranoia adventure Vapors Don't Shoot Back. When the PCs fight Black-U-BRD-5 aboard his pirate ship in the reservoir, it's possible for his robots to be knocked overboard. If they're still operational they can walk along the bottom and climb up a shaft back onto the deck.
 * Basic Dungeons and Dragons adventure CM2 Death's Ride. During the siege of Gollim, a force of undead walk across the bottom of the nearby river and make a surprise attack on the town.
 * Also a tactic of constructs, especially inevitables, who don't tire, don't breathe, and suffer few ill effects from water. (Maybe not iron golems, though.)
 * Warforged from the Eberron setting are explicitly stated to be able to do this. However, since they are made of about 30% darkwood, they can still swim if they try.
 * An undead serial killer, Aldern Foxglove, does this in an early Pathfinder adventure.

Video Games

 * Street Fighter: Among the many feats of Badassitude of Akuma is the ability to walk unfazed along the bottom of the ocean. Which he then jumps off of and splits a submarine passing by in two with his feet.
 * Sonic the Hedgehog can't swim at all--developer Yuji Naka gave him this limitation under the mistaken belief that real-life hedgehogs couldn't swim. So, depending on the game, Sonic either runs underwater or has Super Drowning Skills.
 * Since Sonic 3 in the series, Tails is an odd mix of this and being able to swim quite freely (as a rough analogue to his ability to fly above water). However he tires fast and then sinks. Knuckles also can "glide" underwater.
 * Sonic Adventure 2 and a few of the later 2D installments give Knuckles the ability to swim along the top of the water. In SA2 he can dive, in the 2D games he simply switches to the standard sink-and-walk.
 * In Sonic Colors, Sonic finally learns to swim... sort of. He still sinks like a rock and runs underwater, but he's capable of Double Jumping infinitely while underwater, which is basically swimming in all but name.
 * He loses it in Sonic Generations despite it taking place not long after Colours. The Wisps might be involved in that infinite double jump - except for the white wisps they DO allow him to breathe underwater (and Frenzy moves much quicker when underwater compared to on dry land, to boot!)
 * Mega Man, because he's a robot, natch. He did learn to swim for Mega Man 8.
 * Mega Man ZX has the main characters, when in their 'base' forms (without Biometal) float up to the surface of the water. Otherwise, this trope is played straight.
 * Soma Cruz does the same thing until he gets the ability to play this trope partially straight - like the Sonic Colors example above, he and some other Castlevania protagonists can double-jump infinitely in water.
 * Cave Story: the protagonist and Curly Brace, also robots. (Except for when swept along by a current.)
 * Subject Delta in Bio Shock 2 is permanently fused to his armored Big Daddy diving suit and therefore can walk on the sea floor indefinitely, but is far too heavy to swim.
 * See also: every other Big Daddy, on all counts.
 * Mario in Super Mario 64 when he has the metal suit power up.
 * Super Mario Bros the Lost Levels featured Koopas that can walk underwater.
 * Also Link in The Legend of Zelda when wearing the Iron Boots.
 * Also an ability of Zora Link in Majora's Mask. Zora Link is perfectly capable of traditional swimming; walking underwater is purely optional.
 * Samus in every Metroid game since Super Metroid. The Gravity Suit, which is supposed to allow free movement in water, combines Walk, Don't Swim with Water Is Air. Presumably the suit is still too heavy to permit actual swimming, or it would be improbably difficult to swim straight with one arm significantly larger and heavier than the other. Regardless, Samus's suit means she doesn't have to worry about oxygen, so being underwater is just annoying until you get the upgrade.
 * Metroid Prime 2 gives the player a propeller along with the Gravity Suit, allowing the player to hover a limited distance underwater.
 * In The Secret of Monkey Island, Guybrush is tossed in the sea tied to an idol, and is able to walk around at the bottom. He can also do this in The Curse of Monkey Island (as an Easter Egg) and in Tales of Monkey Island.
 * Snake, in the first Metal Gear Solid and in its remake, The Twin Snakes.
 * In the second game, there is a swimming section where you have to manually open a couple doors. If you stop before opening the door you can walk around on the floor, albeit very slowly.
 * Master Chief, when jumping into the coolant pools during the "Keyes" sequence in Halo. Or if you drive into the ocean on the beach level (no reason to, but hey, you can do it). Justified, as the MJOLNIR armor is stated to weigh well over a ton. The same mechanic is shown in cutscene in Halo 2, in which MC jumps into Delta Halo's "ocean" to avoid a Covenant plasma attack and goes straight to the bottom.
 * Ironically averted with his ragdoll in Halo 3. Nothing like watching more than a ton of solid steel armor float down the river.
 * Played straight in the actual gameplay (when Master Cheif is alive). Jumping into deep water make you sink and kills you instantly (likely for gameplay reasons; Master Cheif should be able to survive it, but since there's no actual way to get yourself out of the deep body of water, you just die). There are some places where the water is deep enough to immerse yourself, but not deep enough to kill you. It can make for handy cover.
 * Creatures who wind up in water in the latter two games in the main trilogy will typically wander around on the bottom until they drown, although there are third-party objects available that will allow certain creatures to swim.
 * The player character in An Untitled Story can't swim, but he sure is buoyant underwater. Said player character is a flightless bird-like creature (but not a penguin).
 * In Nethack you can walk across the bottom of water if you're wearing an amulet of magical breathing. However, each turn spent underwater has a chance of rusting your iron equipment, diluting your potions, and erasing your scrolls via washing out their ink (unless you ); plus, the water current pushes you around. Since there's multiple other ways of crossing water, this is usually reserved as a last resort.
 * Space Station Silicon Valley: Some of the animals you take control of do this.
 * You can alternate between this and normal swimming in Alundra 2.
 * Things with a [NOBREATHE] tag in Dwarf Fortress walk around on the bottom of water-filled areas with a speed penalty instead of swimming. In Adventure Mode, you can choose to wade through water below a certain depth, but have to swim if a z-level is filled with water to the top.
 * In Battle for Wesnoth, skeletons are the only non-flying, non-swimming unit to be able to enter Deep Water terrain, though only slowly and with very poor dodge rates. They also have the "submerge" special ability, which makes them difficult to see when they are in deep water.
 * In X-COM: Terror from the Deep, every unit in an underwater mission walks on the sea bed, except for Tentaculats and Hallucinoids.
 * In Trine, the Knight is the only protagonist who walks underwater instead of swimming. Not too surprising, what with being clad in full suit of plate armor.
 * Warrior Kings has two super units, the Archangel and Abbaddon, doing this.

Webcomics

 * Jones from Gunnerkrigg Court walked from a boat to the shore, rather than trusting her weight to a rickety pier.
 * The opening of Last Blood has a zombified nazi who was buried at sea walking out onto a beach to begin the outbreak.

Western Animation

 * In the episode "Serpent's Pass" of Avatar: The Last Airbender, the Gaang go underwater in a giant air pocket to cross a gap in the Serpent's Pass. It would have worked, too, if not for the giant serpent.
 * In one episode of The Simpsons, Homer gets pulled out to sea by a rip tide and can't swim back. He tries to sink to the bottom and walk back, but gets exhausted after a few steps.
 * In another episode, Principal Skinner presumable crosses a river this way chasing Bart after Bart skipped school.
 * In Superman the Animated Series, Metallo is seen doing this after apparently sinking to his doom.

Real Life

 * This is what tanks do to tread water barriers. One of the reasons Germany had an edge over Soviet Union during the beginning of WW 2 was that the Soviets wanted their light tanks to swim, rendering them too lightly armored to be of any use, while Germans made their tanks able to go underwater and thus able to cross rivers while retaining their combat capabilities.
 * This is how hippos move. They are actually very unadapted to actual swimming, so they walk on the river bottom. QI explains.