A character performs an impressive dive into a lake, swimming pool, or other body of water. The audience is amazed at the diver's prowess... so why are they staring and covering their children's eyes?
Hilarity Ensues when the diver notices their swimsuit floating leisurely on the pool's surface.
According to Rich Hall, this embarrassing phenomenon is known as detruncus and may happen to either a man or a woman. Women are more likely to lose their tops, but not always.
A subtrope of Wardrobe Malfunction. Related to Gone Swimming, Clothes Stolen. Invokes Naked People Are Funny when used for comedy.
- An ad for the Boy Scouts shows this happening to a kid, with the premise being that if he had joined the Boy Scouts, he would have learned how to tie knots properly and prevent this from happening.
- Happens to a young boy in a Camelback Lodge and Indoor Waterpark commercial. His trunks come off and the embarrassed lad has to endure his little sister laughing at him while his surprised mother holds up his wayward trunks.
- Happens to Homer Simpson in a CC's potato chips commercial.
- In a Cinsay ad a man dives into a pool and loses his trunks in front of a number of women. He eventually manages to get a new pair of trunks, but not before an older woman enjoys a peek.
- In a Coke commercial, a tossed bottle of soda goes too far. Two people want it and dive into the water to race for it. Though the young man gets the bottle, the mischievous girl gets his trunks!!
- Two conniving girls relieve an unfortunate lad of his trunks in this part of a Dairy Lea ad.
- In a Digicel commercial a man loses his swim trunks after diving in a pool and a woman takes them. Luckily some swimsuit-clad women give him a towel to cover up. Unluckily the towel snags on a fence and he exposes himself.
- In another Digicel commercial a woman in a pink bikini heads down a water slide only to emerge with her top floating nearby.
- Waves are a bikini top's worst nightmare in this Elma Chips commercial.
- Happens to Smilin' Bob in one Enzyte commercial . Because of what Enzyte claimed to be ("natural male enhancement"), Bob was only too happy to put on a show.
- Happens to a woman's bikini in this Fruttare ad.
- This Havaianas commerical shows a man diving in a pool and losing his speedo. A bikini-clad woman snatches up his small suit and he is forced to cover his private areas with his sandals.
- Happens to an unfortunate young swimmer in a Hitachi DVDCam commercial, allowing the camera's operator to show off its features by quickly deleting the shot.
- A Hope cigarette commercial features a pool scene, which starts off with one bikini-clad girl diving into the pool. Seconds later, her top is shown floating on the water, and at the end of the commercial, same girl is shown, in the pool, covering her bare chest with her arms, with a dismayed look on her face, and then ducking into the water. Humorously played in the same commercial with a guy, who also dives into the pool, and his Dodgy Toupee comes off.
- A variation of this happens in an Irn-Bru commercial. A diver tries to impress two girls at a pool by going off the diving board. However, his speedo snags on the diving board and he falls into and climbs out of the pool in the nude!
- In a Kelloggs cereal ad a pool boy loses his trunks thanks to the pool's drain.
- In this commercial for the Jewish social network Koolanoo, a young woman dives into a pool in front of several young men, causing her bikini top to immediately fall off. As they watch her climb back out in slow motion, one notices that she's wearing a Star of David necklace just like he is, and appears behind her just in time to protect her modesty with his hands.
- Happens twice in this Nova Schin ad. First a man loses his speedo when another man drinks lighter beer much to his disgust. Then multiple women lose their bikini tops when a different man drinks Nova Schin beer much to both his and the women's enjoyment.
- There was an old Snickers commercial where this happened to a surfer.
- A woman realizes it is not a smart idea to wear a strapless one-piece while swimming in this Special K commercial.
- In this Sprite ad, a young man finds it's not very smart to go down a waterslide head first!
- A Team Loush commercial involving an unfortunate young lad losing his trunks.
- In the Angel Blade: Punish! OAV 2, Ayame, a Highly Visible Hottie Ninja, jumps from a diving board on a 99-meter-tall tower. Naturally, she dives into the pool unharmed... except that she loses her bikini in the water, to the great delight of the men around. And yes, in this case, both pieces of the swimsuit come off — it is a Hentai series.
- In Arad Senki Slapup Party, Ryunmei's top ends up coming off while she's playing a game of volleyball. Humorously, the same thing later happens to Baron and Cabensis when they lose their swim trunks to a sea monster.
- In the first Fairy Tail OVA, Makarov loses his speedo, much to the horror of the boys spying on the pool.
- Yuno's bikini top gets washed away at a water park in Future Diary, and she ends up covering her front by clinging to the back of her love interest Yukiteru until the staff can retrieve it for her... but knowing Yuno, she may have done it on purpose as part of her plan to make him fall in love with her.
- Crayon Shin-chan have this happening to both Misae and Hiroshi, in two different manga stories. The former have the upper of her two-piece washed off on a beach, the latter lose his swimming trunks in an indoor pool, both instances resulting in Shin-Chan, Himawari and the one remaining parent pretending they have no idea who's that streaker running towards them.
- A girl knows she is a Butt-Monkey when she has Super Drowning Skills and, during her first day of school, she still ends up thrown into a pool while wearing a one-piece School Swimsuit... which somehow is slippery enough to leave her completely nude. Ryuubi from Ikki Tousen discovers this the hard way.
- Lupin III'':
- Happens to Lupin in The Castle of Cagliostro. He dives underwater after one of the Count's aqua-suited goons. As he swims in pursuit through a tunnel, his boxers start to slip. At the end of the chase, he drags the unfortunate goon back into the tunnel... then reaches out to snatch his boxers before they can float away.
- A chilling example happens in the series, where a woman dives into a pool ahead of Fujiko. Unfortunately for her, an assassin targeting the gang had filled the pool with sharks; the floating bikini top serves as a Dead Hat Shot.
- If you see Machiko-sensei (from Miss Machiko) in a bathing suit, it will inevitably slip off.
- During the Beach Episode chapter of Monthly Girls' Nozaki-kun, Seo steals the drawstrings of Nozaki, Mikoshiba, and Wakamatsu's swim trunks to "create more excitement", and the three boys promptly lose their shorts in the water.
- Happens to Gai in Rock Lee's Springtime of Youth. Lee himself thinks it was Sakura, and he shoves the trunks in her face.
- Happens in School Rumble. Nara thought that it had happened to Tenma and went to retrieve it for her... but it was actually Harima's.
- Tsuda fantasizes that this might happen to Aria in the Beach Episode of Seitokai Yakuindomo. What actually happens exceeds his expectations.
- SHUFFLE!: The first half of episode 9 involves the whole cast enjoying themselves at the beach, including Asa getting her bikini top washed away by a large wave.
- Tamamo-chanís a Fox!: In the second Beach Episode Osaki loses her bikini top after jumping off the diving board, since she's a messenger of Inari the local fishing industry gets a divine blessing after someone finds it.
- This happens once to Princess Allura in Voltron (a.k.a. Princess Fala of GoLion). A high dive while wearing a bikini leads to her top surfacing before she did.
- In an Archie Comics story, Veronica was upset that Archie was paying more attention to his fishing than her, so she grabbed a spare swim suit, hooked it to Archie's line, and told him he hooked her suit (the one she was wearing). Then she let him reel it in and told him he'd pulled it off of her. The rest of the story involved Archie trying to find something for her to cover up with.
- Invoked in the Beach Issue of Mazing Man. Guido gets a bunch of girls in bikinis to go into the water with him and flap their arms, because at least one of their tops will come off. It happens all right — to the ugly chick. Cue In-Universe Squick.
- The cover◊ for the Spirou compilation #309, with characters from the French-Canadian comic Les Nombrils, features such an incident, with Jenny's top staying afloat above her while she's at the bottom of the swimming pool.
- Seen in a strip of Le Petit Spirou. Spirou and his friend Cassius are at the beach, waiting to get into the water by counting the waves. On cue, the 75th is bigger than the others, stripping the girls from their class as well as their Hot Teacher from their swimsuits — at which point the boys jump in with diving mask and snorkel to see underwater.
- The November 24, 1992 strip has Jon Arbuckle lose his swimming trunks after jumping into the water at the beach. Other beach-goers from off-panel shriek at the sight of Jon sans swimming trunks, with Garfield remarking that he hates the beach, but it does have its moments.
- In the October 28, 2022 strip, Garfield watches a movie where a sea monster emerges from the water, only to go back in out of embarrassment over losing his swimsuit.
- Happens to a teenage April in one For Better or for Worse comic on a beach outing.
- In It's Always Bunny in Mustafu, Mirko's swimsuit strap breaks during swim training with Izuku. It slips down to her waist giving him quite the eyeful.
- In the short Invader Zim fic "What Goes Around", Dib and Zim get into a fight while on a school field trip to a lake. Tossed into the lake, Dib instinctively lashes out to grab something that he can use for support, and unfortunately grabs Gaz's bikini top where she's standing next to where he landed. His weight causes it snap right off, causing Gaz to flee in embarrassment.
- Buster Keaton loses his oversized rental suit in a public pool in The Cameraman.
- Done in Diary of a Wimpy Kid: Dog Days. Greg loses his swimsuit on the diving board, and in order to spite him, a little girl throws it on a post close to the entrance. Greg is forced to stake out in the pool without anyone seeing him, including his swimsuit wearing crush and a girl with goggles. He eventually manages to get an extra suit... a pair of pink short-shorts.
- Home Alone 2: Lost in New York: When Kevin cannonballs into the hotel pool, wearing swimtrunks that were meant for his dad.
- The Little Rascals movie in 1994 had this happen to Alfalfa, but he was swimming in his underwear. And to make matters worse, Darla and Waldo saw everything from the hot tub!
Darla: Alfalfa! This is a side of you I've never seen before!
- In The Surfer King, this happens to a girl when two guys tell the guy operating a surf simulating ride to turn it up. It causes her bottoms to come off, but she fails to notice and walks away.
- Some mischievous boys slip a hook into the back of a rival's speedo in Swim Team so that when he jumps into the water his speedo rips off.
- It happens to Brandy twice in The To Do List First she loses her bikini top at the public pool after coming down a water slide, much to the excitement of the crowd. She loses it a second time after coming down another water slide while swimming with her crush.
- A variant occurs in the Big Time Rush episode "Big Time Reality", in which Kendall's swim trunks drop after he gets out of the pool. While he pulls them up before anyone can see him, he quickly realizes that one of the cameras installed at the pool due to the band's producer commissioning for them to become the subjects of a reality show was behind him at the time and he spends the rest of the episode trying to get the footage destroyed.
- On British reality TV show Coach Trip, the contestants were taken to the Olympic pool in Barcelona to learn the basics of high-diving. Proceedings came to an embarrassed halt when a buxom young girl from Sunderland performed an impressive dive - losing her bikini bottoms on contact with the water. This was captured for posterity and screened to the nation at five in the evening, albeit with pixellation.
- Even Stevens: Louis was trying to show his dad that he could be serious in a swimming contest.
- On Fear Factor, three female contestants lost their bikini bottoms during a water challenge.
- In the Pool Episode of Masked Rider, Patsy angrily shoves Herbie into the pool. Herbie comes back up and asks "What's so funny?" when everyone laughs at him, not noticing his swim trunks are floating nearby.
- In the Mr. Bean episode "The Curse of Mr. Bean", the title character, after finally gaining enough courage to perform a high dive at a pool (or, rather, trying the patience of the boys waiting immediately behind him for long enough that they effectively force him over the edge), loses his swimsuit as he hits the water, and is unable to stop a young child from curiously scooping it out of the pool with a snorkel. Then the lifeguards blow the whistle to clear the pool; he is able to duck under the water (coming up for air every few seconds) until the lifeguards leave, and then makes his way to the changing room, only to discover the pool was being cleared for a female swim team's practice session...
- In this episode of Pobre Rico a guy jumps into the pool and loses his trunks much to the humor of his attractive bikini wearing neighbor!
- On Shake it Up we get this exchange:
CeCe: Remember when we were at camp and I wanted to race those canoes?
Rocky: They were very unstable.
CeCe: No, I'm very unstable! I tipped over the canoe, cut my lip, and my top came off!
Rocky: CeCe, you were ten. Nobody even knew you were a girl.
CeCe: I KNEW!
- Subverted in a Beach Episode of Who's the Boss?. Angela is rescued from the surf and wrapped in a towel. When Tony comes to see if she is alright, someone from the crowd hands her her top, and Tony assumes that this trope is in play. Turns out that not only did she remove it herself, but several people from the crowd actually saw her do it, much to her surprise and embarrassment.
- The Worst Year of My Life, Again: Alex loses his broadshorts and the bathers he was wearing under them in the waterslide on the last day of summer. Due to the loop year, this happens twice.
- In the Beach Episode of Zoey 101, Dustin loses his trunks. He's so embarrassed that he refuses to leave the water, and by the end of the day he's sick and miserable.
- Back in 1969, Gerard Cox sang "Broekje in de Branding", a Dutch song which translates as "Bottoms in the Surf". It's about some lost bikini bottoms, and that there must be some helpless woman in the water somewhere.
- In Data East's Playboy 35th Anniversary pinball, a woman in the swimming pool covers her breasts with her hands after losing the top of her bikini. Because the Playboy Mansion is no place for indecent exposure...
- Real Bout Fatal Fury: Blue Mary may fall into water after she knocks her opponent out. When she comes back to the surface, she frantically covers her chest, as her top came off underwater.
- In Persona 4 Golden, during a trip to the beach, Teddie tries to cause this to happen to one of the girls. However, the actual slippery swimsuit ends up being Kanji's.
- Valkyria Chronicles II has a scene where Aliasse drags Juliana into the pool and due to not watching where she's grabbing, accidentally removes her bikini top. Avan and Zeri stare in awe, while Cosette compliments Juliana's "form". Naturally, Juliana is pissed.
- Layla of Eerie Cuties once loses her top to a treacherous wave. Too bad (for onlookers) it's at night and too dark to see anything... except for the resident werecat.
- In Grrl Power, Sydney makes Harem lose her bikini top in the pool after pranking her with Halo's recently discovered air-generating orb.
- This strip of Kevin & Kell has Rudy losing his swimming trunks after swimming in the water and drying off by shaking.
- In this Transmission strip, Howard and Jeanette decide to race each other down a water slide, and learn the hard way why you don't go down head-first when they both reach the bottom before their suits do.
- Played with and averted in As Told by Ginger: A group of high school girls conspire to remove Courtney's bikini top at a pool party and reveal not just her body, but also the fact that she stuffed her top to appear more adult. Averted when the main characters find out and counter-plan to help cover up Courtney and retrieve her bikini top before anyone sees much.
- Big City Greens: In the episode "Swimming Fool", Hilarity Ensues when Bill's trunks get sucked into the jets of a jacuzzi pool, leaving him naked and unable to leave in fear of getting spotted.
- A variation in the ChalkZone episode "The Gift of Good Intentions" happens Rudy gives his dad a pair of Bermuda swim trunks from Chalkzone for his birthday, and then has to rush to the public pool to stop this from happening to his dad since his swim shorts are made of chalk and will dissolve in the water.
- Mentioned in an episode of Clifford's Puppy Days, where Nina says her swimsuit fell off during a dive because it was too big.
- Numbuh One loses his trunks in the Codename: Kids Next Door episode "Operation: B.U.T.T.", resulting in an avalanche of jokes about how big his butt is.
- Dexter's Laboratory: After spending all day trying to avoid being pushed in, Dexter eagerly jumps into the pool. Unfortunately. his swimsuit falls off right before he gets out of the water.
- Occurs in an episode of Dilbert but not to a member of the main cast. An important business client recalls the story of his biggest shame, jumping into a lake when he was a kid, losing his trunks and being forced to walk out of the lake completely nude while all of his friends and family were watching, earning him the nickname "acorn" which haunts him for the rest of his life. Acorn just coincidentally happens to be the name of the new business idea they created for him, however.
- In The Fairly OddParents! episode "Emotion Commotion!", the embarrassment of losing his swimsuit in front of his crush causes Timmy to wish he had no emotions.
- In the Family Guy episode "From Method to Madness", Peter rescues a man from drowning after he was sucked out to sea by the riptide, and he gets pulled out no worse for wear sans being butt-naked. However, it's not until the man invites Peter and his family over for dinner that we learn he didn't lose his bathing suit at all; he and his family are nudists.
- Happens to Lucius on Jimmy Two-Shoes, because he loaded his swimsuit with stolen pirate gold.
- Discussed in the King of the Hill episode "Four-Wave Intersection:" There was an urban legend of a kid who lost his swim trunks in the water park's giant slide. Or rather, according to the rumor, a kid went down, and the only part of him that anybody saw after was his swim suit.
- In the Popeye short "Alona of the Sarong Seas", this happens first to Olive, then to Popeye and Bluto.
- Rated "A" for Awesome: Happens to Les in one episode where he loses his baggy trunks at the local water park. As he is sneaking around naked trying to get them back, the trunks get jammed in one of the water jets and threaten to cause an explosion. Made even funnier by the fact that this happened after he criticised Lars for wearing a tight thong.
- In the Scaredy Squirrel episode "Mr. Perfect Balsa", Paddy's swim briefs slide off in the pool after Scaredy pulls a prank on him.
- Stōked: Emma loses both halves of her bikini after a particularly spectacular wipe-out in "All We Are Saying is Give Reef a Chance", leaving her naked as other surfers look on.
- Total Drama:
- On the episode "Haute Camp-Ture" of Total Drama Island, Izzy emerges from the pool having found a bikini bottom. Katie then points out that it's her own bikini bottom. She quickly dives back under the water, exposing her lower half in the process.
- Owen loses his trunks during the first ever challenge on Total Drama Island, and during the opening animation of Total Drama World Tour.
- This trope is the primary reason that surfers tend to wear wetsuits.
- Actress Jayne Mansfield orchestrated her discovery this way. She untied her bikini top as she was diving into the pool at the launch party for the Jane Russell film Underwater! She emerged topless and feigning embarrassment, upstaging Jane Russell at her own event. As the pool was surrounded by reporters and photographers, she made quite a splash and got a contract with a major studio within a week.
- Katy Perry once went on a water-slide at Raging Waters park in California, and accidentally mooned everyone at the water park. The paparazzi were on hand, of course. Perry wrote on Twitter on August 13, 2012, "Let's be fair, I really think I deserve a season pass for that ass. Oh, and some flip flops."
- This once happened to Kirsten Dunst on a beach.