- Patchy the Pirate (original airing only)
- Potty the Parrot (original airing only)
- SpongeBob SquarePants
- Gary the Snail
- Squidward Tentacles
- Patrick Star
- Abigail Marge
- Pearl Krabs
- Charles (debut)
- Jellyfish (cameo on sign)
- Seahorse (mentioned)
- Eugene H. Krabs
- Tibor (debut)
- Mermaids (debut)
- Debbie Rechid
- Frankie Billy
- Harold Bill Reginald Scott
- Fred (blue)
- Nancy Suzy Fish
- Nat Peterson
- Tina Fran
- Sheldon J. Plankton
One night in Bikini Bottom, a mysterious fog appears and the voices of mermaids are heard singing. That morning, SpongeBob realizes his alarm clock, Gary's shell, Squidward's clarinet, Patrick's cuff links, and Mr. Krabs are missing. While investigating, SpongeBob, Squidward, and Patrick are sucked into the triangle. They find Mr. Krabs, who tells them that he loves all the piles of "resellable stuff." He realizes that Pearl is left alone at the Krusty Krab with all his money, but she gets transported to the triangle too.
Pearl and Squidward relax, Mr. Krabs looks for change, and SpongeBob and Patrick look for the mermaids. The mermaid quintet only knows how to "surround themselves with cool new stuff" whenever they feel like. They call SpongeBob's dilemma "TNOP," which stands for "totally not our problem." SpongeBob tries to leave with Patrick but the latter is love-struck and decides to stay with the ladies.
SpongeBob leaves and quickly says he was unable to get information upon return, and being noticeably wounded by the Triangle, he simply collapses and is dead. Mr. Krabs realizes SpongeBob desperately needs a Krabby Patty. He finds one close by and feeds it to SpongeBob, who becomes alive and well. He then wonders who makes that Krabby Patty. Suspecting that Plankton might have stolen the formula, Mr. Krabs intends on getting back to the Krusty Krab as soon as possible.
The whole group goes to the mermaids, but they are again refusing to help. Not bothered, Pearl tells her father that she wants to go to the mall, as the confused mermaids questioned this concept. Pearl explains what a mall is and the amazed mermaids want to go too. Once Mr. Krabs remarks on this, SpongeBob has an idea and hypothesizes that if the mermaids sing their song backwards, it will also reverse the effects of the vacuum. With this, the mermaids begin to sing backwards and this causes everyone to get sucked back to Bikini Bottom along with the items. Pearl and her new mermaid friends run to the mall while everyone else looks into the pile to find all of their missing things. While everyone is reclaiming their property, Mr. Krabs wants to see whether Plankton is actually trying to steal the formula again. He finds the old sailor fish Charles who SpongeBob met earlier, cooking the Patties on the grill. It is revealed he decided to help out the restaurant while the staff were gone and has caught Plankton in a jar as he was trying to steal the formula himself. Mr. Krabs is relieved to know that his recipe was safe and sound. Patrick then finds his cuff links and puts it on his tuxedo. He leaves out and says to the driver "Home, Reginald" and then steps inside the limo and drives off.
SpongeBob tells Patrick he dropped his cummerbund as the episode ends.
|( ‣ ) Associated production music|
|( • ) Original music|
|( ◦ ) SpongeBob music|
‣ Out of the Crypt - Harry Lubin [Title card]
‣ Unknown Track 84 - Opening
‣ Lap Steel - Nicolas Carr [the next morning]
‣ Vibe Sting - Nicolas Carr ["Hey, where's my alarm clock?"]
‣ Dramatic Bridge 1 - Phil Green [Gary's shell missing]
‣ Jovial Pirates Jig - Michael Bolger, Nicolas Carr [at the Krusty Krab]
‣ ? ["Reporting for duty, Mr. Krabs."]
‣ Vibe Sting - Nicolas Carr [Krabs' office is empty]
‣ Sailor's Sting 6 - Michael Bolger, Nicolas Carr [SpongeBob looking for Mr. Krabs]
‣ The Great White - Gregor F. Narholz [sea captain talks about Bikini Bottom Triangle]
‣ Unknown Track 84 - Mermaids' song
‣ Drama Link (g) - Hubert Clifford [SpongeBob and Squidward scream as they ascend]
‣ Steel Sting (f) - Jeremy Wakefield [Squidward in a gumball machine]
‣ Steel Sting (a) - Jeremy Wakefield [SpongeBob eating gumball]
‣ The Great White - Gregor F. Narholz [SpongeBob and Squidward in the Bikini Bottom Triangle]
‣ Blue Tide - Sage Guyton, Jeremy Wakefield ["Mr. Krabs is gone."]
‣ Hawaiian Beauty - Lionel Wendling [Krabs being massaged]
‣ Befuddled Gent - Phil Green [Krabs explains]
‣ Unknown Track 84 - Mermaids' song again
‣ From the Dead - Ronald Hanmer [Avalanche of stuff]
‣ Steel Link (b) - Jeremy Wakefield ["Patrick!"]
‣ Woe is Me! - Richard Myhill ["Oh, me sweet little girl, all alone..."]
‣ Lovely Scenery (c) - Mladen Franko ["...with me cash register!"]
‣ Tipsy Turvy - Phil Green ["Get me out of this trash heap!"]
‣ Marvellous Singers - Marc Durst [mermaids revealed]
‣ Unknown Track 84 - Mermaids start to sing
‣ Lite Conversation - Nicolas Carr, Barry Anthony ["Um, can I help you?"]
‣ Harpsichord Classical Bits - Barry Anthony ["Little one? How dare you, sir."]
‣ Hawaiian Cocktail - Richard Myhill [SpongeBob passes out]
‣ Harpsichord Classical Bits - Barry Anthony [Dime falls into Krabs' pants]
‣ Hawaiian Cocktail - Richard Myhill ["SpongeBob? SpongeBob, boy-o! SpongeBob, can you hear me?"]
‣ Dramatic Impact 5 - Ivor Slaney ["Your Krabby Patty meter's on empty!"]
‣ Unknown Track 84 - Mermaids' song again
‣ Harp Ding - Nicolas Carr ["...Krabby Patty!"]
‣ Unknown Track 37 - Nicolas Carr [fanfare]
‣ Short Rising Tension Bits - Nicolas Carr, Sage Guyton, Jeremy Wakefield ["Wait a minute, I didn't make that Krabby Patty!"]
‣ Vibe Q Sting - Nicolas Carr ["So... how do we get out of here?"]
‣ Daily Chores Jig - Michael Bolger, Nicolas Carr ["Well, I think you don't know how to talk to the ladies."]
‣ Steel Licks (d) - Jeremy Wakefield ["So there's really no way out of this place?"]
‣ Befuddled Gent - Phil Green [Pearl explains what a mall is]
‣ Unknown Track 84 - Mermaids' song backwards
‣ Grass Skirt Chase - Sage Guyton, Jeremy Wakefield [vacuum reversed]
‣ Magic Potion 1 [#95] - Harry Bluestone, Emil Cadkin [Pearl and mermaids go to the mall]
‣ Hawaiian Party - Peter Dennis ["Hello, miserable life, I'm back."]
‣ Attack - Anthony Hymas [Krabs goes into the kitchen]
‣ Salty Krab Jig - Michael Bolger, Nicolas Carr [sea captain cooking patties]
‣ Curtain-Raiser - Alan Braden [Patrick finds his cufflinks]
- This episode is available on the Legends of Bikini Bottom, Complete Seventh Season, and Next 100 Episodes DVDs.
- To promote the premiere of this episode, the Nickelodeon website featured a story from Patchy about the mermaids of the Bikini Bottom Triangle. Viewers could ask Patchy questions about his journey on the Nick.com message boards.
- Although this episode premiered in 2011, it was made in 2009 according to the credits.
- The production name for this episode was "Welcome to the Bermuda Triangle," as seen on some of the original character storyboards on Facebook.
- In the Turkish version, TNOP (Totally Not Our Problem) is BHAE (Bizi Hiç Alâkadar Etmez), which translates to "It Does Not Concern Us At All."
- The title card is similar to "The Donut of Shame," but it is not animated.
- This is the second time Patrick falls in love with a mermaid(s).
- Mr. Krabs mentions the Dutchman's Triangle in "SpongeBob SquarePants vs. The Big One."
- A table from the Krusty Krab can be seen after it warps.
- When SpongeBob says "Oh Mr. Krabs!," there is a sign that says "Save the Jellyfish" from "SpongeBob's Last Stand."
- This episode takes place after that episode.
- This episode premiered eight years after the release of Tales from the Deep, Bikini Bottom Bash!, and Deep Sea Sillies and six years after The SpongeBob SquarePants Movie was released in Spain.
- Numerous objects that appear in The Bikini Bottom Triangle are references to past episodes.
- This is the first time that the APM track "Lite Conversation" is used.
- The Bikini Bottom Triangle is an obvious spoof of the Bermuda Triangle.
- When Mr. Krabs says "So it must have been that rotten pipsqueak, Plankton," his left sleeve turns red for a split second.
- After SpongeBob finds Mr. Krabs, they go to the vacuum.
- Before the things come out, Mr. Krabs has only a towel on. When he pops out of the things, he has clothes.
- Charles says "And poof! Your cuff links are gone. Never to return!" to SpongeBob, instead of to Patrick.
- When Pearl is working at the Krusty Krab, Patrick is heard speaking in the background but he is not seen.
- SpongeBob forgot to look for Gary's shell and his alarm clock.
- Squidward also forgot to look for his clarinet, too.
- When Mr. Krabs was worried about Pearl being alone with his cash register, it can be seen next to him.
- Patrick keeps on asking about his cuff links.