When the Planet Express company takes a fishing trip over the ocean, a colossal-mouth bass ends up dragging the entire ship under the sea. While the crew works on repairs to the ship, Fry falls in love with a beautiful blonde mermaid, and soon has to choose between leaving the Planet Express crew or staying with his new girlfriend in the (now undersea) city of Atlanta, Georgia.
- Arbitrary Skepticism: Fry points out how weird it is that despite having a crustacean alien as a coworker, no one believes that he saw a mermaid. Justified since in the future that Futurama takes place in aliens are commonplace while mermaids are still regarded as mythical.
- Artistic License Biology/Hollywood Evolution: When Bender points out that it would generally take millions of years for humans to evolve into merpeople, and questions how the people of Atlanta could've done so in less than a thousand, Umbriel explains that the leaking caffeine from the Coca-Cola plant had greatly sped up the evolution process.
- Artistic License Physics: The ship is pulled underwater and manages to withstand the pressure all the way to the bottom (they're specifically stated to be at "the exact center of the Atlantic Ocean"). There's a bit of a lampshade hanging here, since when the Professor is asked how many atmospheres of pressure the ship can withstand, he says (with some sarcasm) "Well, it's a spaceship, so anywhere between zero and one." (Futurama loves to play fast and loose with physics in general, so this isn't the worst example of bad science even in this episode.)
- Ass Shove: The Professor's anti-pressure pill, used to help people survive at crushing pressures, is too big to swallow. Good thing it's a suppository. The rest of the crew is put off with the Professor disturbing fine with it that way.
- Bait-and-Switch: When the crew comes across the sunken city and remove some of the seaweed from the name, the audience is being lead to believe that it's Atlantis. It turns out to be Atlanta.
- Bowdlerise: When this episode aired on Cartoon Network's [adult swim] block and TBS's "Too Funny to Sleep" block, the part where the Professor exclaims, "Sweet zombie Jesus!" after seeing the fish jump out of the water is edited. On Adult Swim, the line was "Sweet zombie [mute]" while on "Too Funny to Sleep," the entire line was cut. The line is uncensored on FOX (which usually would cut out any use of the word "Jesus" as an oath, since they did it to Seth MacFarlane's shows), the DVDs, Netflix, and Comedy Central.
- On Channel 4 in the UK, the part where Bender learns that the crew is on international watersnote and calls in a man to make an illicit deal (with Bender telling Fry and the Professor, "Hey, guess what you're accessories to.") was cut.
- Cassandra Truth: Nobody believes Fry saw a mermaid, chalking it up to ocean madness. Even when they find out he was telling the truth, they never apologize for disbelieving him.
- Cut His Heart Out with a Spoon: Hermes hates Nibbler so much he wants to put him in a sack, throw the sack into a river and hurl the river into space.
- Fanservice: Amy in a bikini in the first third of the episode.
- Fishing Episode: The episode begins with Hermes returning with a pet license for Nibbler, only he got a fishing license by mistake. A mandatory fishing license. So the Planet Express crew have to go fishing in the middle of the Atlantic Ocean.
- Fishing for Sole: Leela tries to use a harpoon to fish, but keeps getting boots. Even when she says she caught something twenty times heavier than a boot, she ended up catching a crate of ten pairs of boots.Amy: Oh, so this is where you shop for your boots.
- Giant Novelty Check: After catching the colossal-mouth bass, Prof. Farnsworth is given a giant check for breaking the world record for heaviest fish caught. Bender gladly pockets the check. Then Fry falls from the bass' mouth, dropping its weight below the record, and the mayor takes the check back, planning to give it to "some giant orphans."
- The Last Straw: After Atlanta was relocated to the ocean, it began to sink due to overdevelopment—it was a statue of Ted Turner that put it over the top.
- Literalist Snarking: When the Planet Express gang goes fishing.Leela: I'm afraid you're both out of your league, boys, 'cause you're looking at a woman who owns her own harpoon!
Bender: (laughs) Harpoon, my ass!
Leela: Okay. (stabs Bender in the butt with her harpoon)
- Mermaid Problem: Fry ultimately leaves Umbriel to be with his friends after realizing that, as a human, he won't be able to have sex with her after she explains how sexual intercourse between merpeople works.Umbriel: I'm not your first time am I? I lay my eggs, and then I leave, then you release your fertilizer.
Fry: (racing to catch up with his friends) Why couldn't she have been the other kind of mermaid, with the fish part on top, and the lady part on the bottom?!"
- My Friends... and Zoidberg: In the promotional video, Donovan explains that all the important people left Atlanta when it began to sink: "Ted Turner, Hank Aaron, Jeff Foxworthy, the man who invented Coca-Cola, the magician, and the other gods of our legends... and also Jane Fonda was there" (she and Ted Turner were married at the time the episode aired).
- No Party Like a Donner Party: With the Planet Express ship stuck underwater, Hermes quickly proposes cannibalism and suggests a lunch of lobster Zoidberg...I mean, lobster Newberg...I mean, Doctor Zoidberg.
- Not Helping Your Case: Umbriel tries to explain that Atlanta was more than just a hub for airplanes, showing off all the great sights the city had...topped off with the airport.
- Ocean Madness: What everyone thinks Fry has—be mindful that this is no excuse for ocean rudeness.
- Parody Assistance: Singer Donovan does a parody of his song "Atlantis".
- Putting the Pee in Pool: Occurs in two consecutive scenes. In the first, the mermaid swimming next to Fry remarks, "Did the water just get warmer?", and later, while next to a volcanic vent, she remarks, "Did the water just get cooler?".
- Rule of Funny: Zoidberg's house burns to the ground... underwater. Zoidberg wails "How could this have happened?" and Hermes notes, "That's a very good question." Implicitly claiming responsibility, Bender picks his still-lit cigar out of the ruins and puffs on it eliciting a cry of, "That just raises further questions!"
- What makes that really funny is that they explain everything that happens in that episode with pseudo-science (in fact, most of the episode is things being explained away.) But for that one last thing, there's absolutely no scientific reasoning.
- Seashell Bra: Averted. Umbriel wears a tube-top.
- Skewed Priorities: When the whole ship sinks into the ocean floor, Bender's only problem seems to be that the colossal-mouth bass he tried to catch with Amy's parasol got away.
- Suntan Stencil: Bender takes Amy's parasol, results in her getting a sunburn. Bender assures her he put sunscreen on her back, but only enough to write "Honk if Bender is great".
- Take That!: The episode takes multiple digs at Atlanta.
- Underwater City: Atlanti... er, Atlanta.
- Voodoo Shark: Played for Laughs when Zoidberg's home burns down... underwater. Also provides the current quote for the trope page.Zoidberg: My home! It burned down! How did this happen?
Hermes: That's a very good question.
Bender: [picks up a still smoldering cigar from the ashes] So that's where I left my cigar. (smokes the cigar)
Hermes: That just raises further questions!
- You Have to Believe Me!: Fry can't convince the others that he saw a mermaid.