Underwear Swimsuit

Lincoln: Anyone got any extra swimsuits we can borrow?
Artie: Nah, but we're all dudes here. Just go in your skivvies.

— The Loud House, "Pasture Bedtime"

A character wants to go for a swim, but for some reason doesn't have a swimsuit with them (maybe they forgot, the idea to go swimming was made up on the fly, or they don't even have one at all). They also don't feel like Skinny Dipping. The solution; just have them use their underwear as an alternative.

A character can also be forced to resort to this if they suddenly find themselves in need to go into water, like when they have to rescue someone or to get out of danger, and swimming fully clothed would be impractical or even dangerous. There are also cultures where their bathing suit or swimsuit would basically be the same thing (e.g. Fundoshi).

Of course, the downside of this is that the character has to wait for their underwear to dry up afterwards before they can dress up again, but it's better than nothing. There are also some other problems that can arise from this; first, unlike swimsuits, underwear was not exactly designed for the purpose of swimming. Also, although they cover up the exact same parts of the body, so there's no difference in what other people can and can't see, wearing just underwear is still considered somewhat of a taboo (especially for female characters) while swimsuits are perfectly acceptable. As such, it can lead to an embarrassing situation if the character is caught swimming by someone they'd rather not be seen by while wearing just their underwear, even if they wouldn't feel embarrassed if that same person saw them swim wearing a swimsuit. In particular if the underwear in question is of the Goofy Print kind.

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Examples:

Advertising

• Captain Morgan's "To Life, Love & Loot": Apparently a showdown between two 17th-century gunships can be averted by the eponymous captain stripping down to his underdrawers and doing a 720 off the plank.
• Coke light... have a great break: An impromptu dip by a handsome holy man finds a woman observing his reverse-striptease before realizing the truth and embarrassingly accepting his blessing of forgiveness.

Anime & Manga

• Akame ga Kill!: When Akame and Tatsumi go hunt for fish, the former strips down to her underwear so she can swim and catch the fish personally.
• Akazukin Chacha: Episode 23, the students of Urara School have to participate in a race to a mountaintop, and the first obstacle is crossing a lake. Riiya's solution is to simply strip to his boxers, tie his clothes on top of his head, and swim across.
• Dinosaur King: In one episode of the anime, Ursula is lounging on a beach, making Zander and Ed wait on her in their underwear. She tells them people will think that they're in their bathing suits, but even they know that won't work because of the looks they're getting from everyone else.
• Dragon Ball Z: In the Garlic Jr. Saga episode "The Heavens Tremble", Gohan strips to his underwear to catch a fish in the river. Then Krillin and his new girlfriend Maron drop by. While Gohan doesn't mind them seeing him like this, it does earn him a remark from Maron who wonders if he always hangs around in his underwear. Goku himself also does this later on in the Cell Saga while searching for a Dragon Ball underwater.
• Fisherman Sanpei (the anime that Sanpei The Fisher Boy was adapted from), main character Sanpei Mihira frequently swims in his undies in order to catch fish.
• Gintama in Chapter 322 Shigeshige swims in his tighty-whities, the only type of underwear he wears.
• Lupin III:
  • In general, Goemon often swims in his Fundoshi due to his traditional Samurai ways.
  • In The Castle of Cagliostro, Lupin and Zenigata are forced into swimming in their underwear to escape from the dungeons of the castle. Lupin actually loses his boxers while chasing a fleeing minion underwater.
• Mobile Suit Gundam has Amuro stuck on the titular "Cucuruz Doan's Island" in only his undershirt and boxer shorts. He takes the former off to go for an exploratory swim.
• Pokémon: The Original Series: In the Christmas Episode Holiday Hi-Jynx, when the protagonists are on their way to the North Pole, but their water Pokémon get too tired to continue pulling the raft, Ash strips down to his boxers and jumps into the water to take over. He quickly tires out as well.
• Happens practically every time the girls of Are You Lost? need to be in the water. It's expected since the girls are all trapped on a deserted island thanks to a plane crash and all the clothing they have are the school uniforms they are wearing.
• The show Salary Man Kintaro has Kintaro and his boss try to save a family as their car nearly falls off a cliff, Kintaro is completely naked and his boss strips to his Fundoshi.

Asian Animation

• The Lamput episode "Skinny at the Pool" features an accidental version of this trope. Slim Doc, yet again attempting to catch Lamput, leaps over the wall of a barbed-wire topped pool wall, accidentally ripping off his uniform. This causes him to look like he's wearing a speedo, thus getting him mistaken for a contestant at a swimming race.

Comic Books

• In one issue of Archie, one girl was showing off a sexy new two-piece bikini that she found in Veronica's bedroom. Veronica informed her that it wasn't a bikini, it was her underwear, to which the girl immediately freaked out because she was wearing a bra and panties at the pool (the joke being, of course, there's no difference between a two-piece bikini and underwear.)
• Junior Braves of the Apocalypse: One of the activities for a camping trip is swimming, since some of the campers lack swimsuits, one of the older counselors suggests swimming naked, however his age contributes to his lack of understanding of how creepy it sounds to suggest that to children. The Braves without swimsuits decide to swim in their shorts or underwear
• Suske en Wiske: In De Vonkende Vuurman, when Lambik and Sidonia learn that the villains tried to dispose of Suske and Wiske by throwing them in a pond tied to a train rail, Lambik quickly strips to his underwear and dives into the water to find them. He fails, but fortunately because they already escaped thanks to a Deus ex Machina.
• In one issue of The Scrameustache, Khena needed to dive into the water to retrieve a belt. Not having a swimsuit with him, he undressed to his briefs and plunged into the water.

Comic Strips

• AJ & Magnus: Happens on the cover for Everyday Adventures.
• Crabgrass: Kevin and Miles swim in their underwear in one comic. It leads to an embarrassing situation for the two when Kevin's sister Krystal steals their clothes.

Fan Works

• In the PJ Masks fanfic Interesting Times, in chapter 18, Greg and Connor go swimming in the pond in Greg's section of HQ. They realize too late they left their swimsuits at home (normally they keep them in a locker in HQ, but they took them home last time to be washed), so Greg suggests they try swimming in their undies instead, to which Connor agrees.

Films — Animation

• Atlantis: The Lost Empire: When Kida and Milo prepare to dive underwater to investigate a mural, Milo strips to his boxers to swim, while Kida removes her sarong (which leaves Milo momentarily Distracted by the Sexy).
• Porco Rosso: Fio takes a swim in her undies to relieve stress after the encounter with the pirates in Porco's cove.
• Summer Days with Coo: While in the countryside, Koichi and Coo come across a river. Coo goes for a swim, and Koichi strips down to his undies to join him.
• The Little Mermaid II: Return to the Sea: Ariel's daughter Melody often sneaks out of the castle to swim and pick seashells clad in her underclothes, comprising of a white chemise with a small green bow on its chest and a pair of white pantalettes. That being said, this film takes place at a time in which swimsuits weren't invented yet.

Films — Live-Action

• Boyhood: At one point in the movie, Mason and his father take a swim in their undies.
• Castaways: Cara and Emily were washed up with only the clothes they had on to the island. After this, they swim multiple times in their underclothes due to this.
• Domino: During a pool party, everyone wears swimsuits except for Choco, who goes in his briefs.
• It (2017): There's a scene where The Losers swim in their underwear at the quarry. No explanation is given however why they resort to this instead of wearing swimsuits.
• The Little Rascals (1994): Alfalfa escapes from Butch and Woim at Darla's ballet recital, and is left in just his underwear and socks after removing his ballerina disguise. The two bullies chase Alfalfa to Waldo's mansion but are held back by the butler. As Alfalfa goes out the back, he is then pursued by a doberman and as he leaps into the pool to escape the dog, his his underwear comes off, leaving him naked, right in front of Waldo and Darla.
  Darla: Alfalfa! This is a side of you I've never seen before!
• Machuca: During swimming lessons at the collegio, the proletarian kids that recently enrolled thanks to Father McEnroe's programm have to swim in their underwear since unlike the rich students, they don't have swimsuits.
• Ondine: When the title character teaches Annie to swim, they both go into the water in their underwear.
• Pirates of the Caribbean: Dead Men Tell No Tales: Her frustration with the incompetent men around her reaching its peak, Karina unashamedly removes her outer clothing (too much according to Henry Turner and not enough according to our old boy Captain Jack Sparrow) and jumps off the boat to reach shore faster.
• Power Rangers (2017): When they're in the forest near the abandoned mine, Jason witnesses Kimberly strip to her bralette and boyshorts before leaping off a ledge into the lake below. Believing her to be drowning, he attempts to strip as well before she gets out and shows up next to him.
• Terror Birds: The five main protagonists strip down to their underwear to wade across a river.
• Tuck Everlasting: Despite their blossoming romance, sheltered rich girl Winnie Foster is still shocked when free-spirited country boy Jesse Tuck strips down to his Long Johns and jumps into the water. Also despite not knowing how to swim, it doesn't take much persuasion for her to do likewise and join him.

Literature

• Buttons McGinty: In one book, Buttons goes swimming in the ocean after arriving in another dimension. However, he has no trunks, so he swims in his underwear, hoping everyone will think they're trunks.
• Black Turtle: Hot Springs Casualties: a group of boys go swimming in a hot spring that they are not allowed to visit. They briefly consider Skinny Dipping, but decide against it and swim in their underwear. After the swim however, they realize their mother might find out they went swimming if she notices their underwear is wet, so they try to wring out the water as best as they can.
• Dirty Bertie: Defied in the story "Bottom!". Bertie forgets his swim trunks at school. His friend suggests swimming in his underwear, but he says no because they have holes in them and it would be embarrassing even if they didn't.
• Flowers in the Attic: Cathy and Chris do this.
• In one Ghosts of Fear Street book, the protagonist and his best friend are magically given twelve hours of Invisibility, which also affects whatever clothes they're currently wearing. Since the community pool is closed that day, they decide to sneak in and swim like this. Unfortunately, the magic wears off after two adults who work there have already shown up, so they have to grab their clothes and run away before they're caught.
• Harry Potter and the Deathly Hallows: A rather grim example. Upon discovering the Sword of Gryffindor at the bottom of an icy pool, and realizing that the only way to retrieve it is by diving, the titular hero removes multiple layers of winter clothing before attempting the deed in his underwear. Aside from the freezing pain, the enchanted evil locket around his neck nearly strangles him to death, which is only averted by the timely arrival of Ron Weasley (who weeks earlier had abandoned the quest for the horcruxes in a fit of contrary pique).
• Henry And Mudge: Henry, his father and his grandfathers do this in Henry And The Great Grandpas.
• In Rain of the Ghosts, Renee tags along on a boating trip where Rain and Charlie need to investigate supernatural shenanigans. They specifically don't tell her that they plan to snorkel, figuring that she can't join them if she doesn't bring a bathing suit. Unfortunately for them, Renee opts for this trope, Lampshading the fact that it's no more revealing than the bikini she wore earlier in the story.
• Who Sir? Me Sir?: In both the book and the 1985 BBC adaptation, the character 'Nails' has to compete in a swimming competition in his underwear after arriving at the last minute without a swimsuit. This doesn't stop him performing exceptionally well.
• The Wind Eye: At one point Mike and Beth need to take to the water; not having brought swimsuits, they have to make do with their underwear. Unfortunately Beth then has to climb a rocky cliff and her improvised swimwear comes to pieces, leaving her naked. This means she gets mistaken for a succubus in the seventh century, and then arrested for indecent exposure when she returns to the present day.

Live-Action TV

• Alias: Justified in "A Missing Link" where Sydney has to quickly improvise a way to escape out of a hotel room, so she strips to her underwear and does a High-Dive Escape out of the balcony and into the pool below, with none of the guests or hotel staff noticing anything amiss as she then casually struts away from the pool in just her underwear.
• Ascension (Miniseries): In the first scene of the first episode, Lorelei, who's left a party, takes off her dress and goes for a swim in her bra and panties.
• Falcon Beach: one episode, a stressed-out woman stranded on an island with a man decides to go, as she puts it, "branty swimming"; in Bra and Panties.
• iCarly: in "iParty with VICTORiOUS", Gibby and Spencer come upon Kenan Thompson's jacuzzi in his house. After the former suggests the latter to get in, Spencer strips to his underwear before doing so since he doesn't have a swimsuit.
• Outlander: A reversal of the usual aesthetic happens in the series 1 episode "Lallybroch". Attempting to clear a blockage underneath the mill's waterwheel, Jamie Fraser removes everything but his linen undershirt and goes for a dip (apparently underdrawers or Long Johns weren't a priority for men in 18th-century Scotland- that's kilts for ya!).
• Smallville: In "Nicodemus", while under the effect of the Nicodemus flower, Lana attempts to seduce Clark by deliberately stripping down to her underwear and diving into the school's pool to lure him into a Two-Person Pool Party. When he's Above the Influence she seductively climbs out of the pool in her underwear but he manages to ignore that too.
• Yellowjackets:
  • In the 1996 timeline, an elite high school soccer team is flying out to a national competition but their plane crashes and the survivors are stranded in the wilderness. In Episode "The Dollhouse", after three days of waiting to be rescued, they hike away from the crash site in hopes of reaching the lake one of them saw. When they indeed find it, most of them strip to their underwear and jump in. We see them frolicking in the water and enjoying themselves in a little respite from their situation.
  • In the 2021 timeline, Shauna and Adam strip down and jump off a bridge and into a river as part of their illicit (Shauna is unhappily married) affair.

Video Games

• The Legend of Zelda: Breath of the Wild: Link can ditch all his clothing down to a pair of boxers, and swimming in just them gives him slightly faster swim speed than swimming with clothes on (save for the Zora Armor and the Salvager Set.)
• In Super Mario Odyssey, the player can clad Mario in just his boxer shorts and go swimming in them.
• Guild Wars 2: The "Dive Master" achievement calls for donning diving goggles at various places around Tyria and going for a dip. Donning the goggles automatically strips the player-character down to their race's preferred underwear in lieu of a swimsuit.

Visual Novels

• Extracurricular Activities: Early on in the Darius route he'll invite you to swim at a secluded cliff area. He'll strip and invite you to join. Considering what type of game this is it's abundantly clear why you two are there.
• Morenatsu: Happens twice in Tatsuki's route. First Tatsuki swims in his Fundoshi during a swimming competition and later on everyone ends up swimming in their underwear during a camping trip.

Web Comics

• Imaginary Summer: In This comic, Dan decides to try out swimming in his underwear at the local pool, claiming he always wanted to do this, but immediately regrets it when some girls start making fun of him.
• Math, of Grrl Power, claims he arrived this way at poolside because he didn't have time to switch to the appropriate swimwear.
• Long Exposure: Mitch and Jonas end up doing this on one of their dates.

Western Animation

• American Dad!: Happens at the end of the episode Lost Boys.
• Avatar: The Last Airbender: Whenever Team Avatar goes swimming, they always strip down to their underwear because they don't have any access to swimwear as a group of traveling kids attempting to stop a global war. Also, unlike most examples, the usual downside of being stuck in wet clothes doesn't apply because Katara and Aang can bend the water out of their clothes instantly.
• Big City Greens: Cricket does this in the intro and later in the episode "Valentine's Dance" to cool off after embarrassing himself in front of Gabriella.
• Bob's Burgers: Two examples. First, is a minor IRS agent in Aquaticism to prove his devotion to the religion indulges in some Naked Nutter shenanigans by stripping to his undies and getting in a tank full of jellyfish. And then Bob does this in The Ring But Not Scary, he thinks he lost his ring at a waterpark and decides to strip to his tighty-whities to search for it in the water.
• Ed, Edd n Eddy: Ed, being Ed, always swims in his underwear. Given his hygienic standards, it's less of an eccentricity and more of a health risk.
• Johnny Test: In "Johnny Test, 90210" Johnny briefly swims in his underwear while in Porklifornia.
• In the Steven Universe episode "Lars And The Cool Kids" when the titular Cool Kids prepare to swim in Dead Man's Mouth, Buck Dewey appears to have stripped down to his boxer shorts, although he could just be wearing regular shorts underneath his pants.
• The Loud House: In Pasture Bedtime, after ditching Liam so they can secretly go to Girl Jordan's party, Clyde and Lincoln swim in their undies since they didn't have any swimsuits with them. They only do so because there are just boys in the pool while the girls are elsewhere. When the girls return, they try their best not to be seen in their undies. It fails.
• Wacky Races: In "Beat the Clock to Yellow Rock", a ranger at Yellowrock Park stops each passing car to check for bears that hide in them to try to sneak out into the city. As this happens, The Anthill Mob decide to pass the time by swimming in a nearby pond, so they strip down to their underwear. While this happens, a group of bear cubs steal the Mob's clothes to disguise themselves so they can sneak out of the park. The ranger catches onto them, and as he leads them away, the Mob chases after them, telling them to come back with their clothes.

Real Life

• Many British adults who went to single-sex schools will remember you could not get out of swimming lessons by claiming you forgot your swimsuit. Any PE teacher worth their diploma would offer a choice: swim in your underwear or swim naked.

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