Fanfic / Drowning in Your Depths

When his crew mutiny under the magically-empowered leadership of his treacherous first mate, fasten him to the mainmast and blow his ship to a watery doom, Bill believes he's finished. But in the depths of the sea, there is other life, and kinder creatures—one even willing to save a life like his, in exchange for an escape from the Implicit Prison of an overly-restrictive home. Together, infamous pirate Captain William Cipher and siren and new First Mate Dipper Pines raise the ruined shipwreck, hunt for Bill's mutinous crew, and set sail for the secrets of their past and their path towards the future. Standing against them are a maniacal traitor, a well-meaning family, Bill's own possibly disturbed mind, and a conspicuously unnamed pirate of the past who ties all of these things together.

Drowning in Your Depths is a Gravity Falls Alternate Universe Fic written by AngstMom formerly updating regularly on Fridays and currently undergoing a massive rewrite.

Warnings for graphic depictions of violence, major character deaths, and explicit sexual content.

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Tropes Appearing in Drowning In Your Depths:

A-N

• Affectionate Nickname: Bill has many for Dipper. Though he often uses Pine Tree (here a joke on Dipper's surname), he also uses Star Fish, Cuddle Fish, and most frequently Angel Fish when he's feeling particularly affectionate or teasy.
• All Myths Are True: Various folkloric figures, creatures, and myths have appeared or been mentioned within the story as if they are fact. Given the infamous superstition of sailors during the Golden Age, this trope blends right in with pirate culture.
• Alternate Universe Fic: A pirate-and-siren style AU, wherein Bill is the pirate and the Dipper the siren.
• Ambiguous Time Period: Zigzagged and subverted. While the story definitely takes place before the industrial era created metal ships, the story's beginning in the Mediterranean initially makes it difficult to place in time and cultural context. Later, as the Mens Scapus heads to the waters off the Spanish Main, more and more era-defining details of the world come into focus: since the Americas are still in the early-middle stages of European colonialism, Caribbean piracy is thriving, and Nassau is being run by pirates who talk as if they've been basing there a while, the era becomes firmly identifiable as The Golden Age of Piracy and, if dared applicable, the year can even be hypothetically narrowed down to sometime after Nassau went from pirate shelter to major political pirate hub, placing the events of the story between 1714 and 1717. However, the story ultimately subverts this as soon as its world's Nassau comes into further detail: despite these clear landmark events, the story gives clear indication immediately afterwards that the world of this Historical Fantasy hasn't actually followed real-world historical events for at least some twenty years prior to the start of the story with the founding of the first Pirate Council—so while The Golden Age of Piracy and the setting of the story culturally parallel, that's the only relation they have.
• Ambiguously Human: Dipper notices during the Blind Eye attack that when Bill snaps, he exudes his own magical "tendrils." This is something impossible for humans—implying that Bill's dangerous snap emotional state, which he calls "the Beast," is a manifestation of Bill having at least a partially inhuman nature.
• Artistic License – History:
  • The cocktail-like dress Dipper is given in Port L'Orient is made of a fabric of such a description that, given its sparkly and slinky nature, either required modern polyesters to be brought back by time travelers just to make it or is worth more than the entirety of the Mens Scapus itself. Or both. And its style isn't exactly contemporary with the 17th and early 18th centuries either; wearing such a dress in Real Life probably would have gotten Dipper written off as a foreign prostitute.
  • Although it's minor, the cast occasionally uses modernisms in their language that make no sense for the setting. For example, Dipper uses the word "blocks" during the pirate council meeting to describe the distance between them and the dozens of armed ships at port. Not only does this terminology not make sense for Dipper to know, but "blocks" only exist in areas that have experienced formal community planning, which didn't even begin to be thought about until about sixty years after the Golden Age of Piracy had ended. This type of anachronism is especially prevalent with language referring to sexuality, sex, and gender; specific words on those taboo subjects at the turn of the 18th century were far fewer in number and very different from the words and contexts used in modernity, the latter being what the story uses.
  • Characters like Rezin make mention of the fact that Dipper is still "a child" and thus shouldn't partake in alcoholic beverages with them. However, until the creation of modern health practices and water cleaning processes, most sources of fresh water were potentially dangerous and infamously prone to contamination, especially in cities which were where most of the behavioral standards like drinking ages were set—and water stored for weeks at sea often wasn't much better. Mixing the water with strong alcohols was the most common way of making it safe to drink. It's therefore very unlikely that pirates would refuse Dipper a drink due to being only 17 during the Golden Age of Piracy, considering he likely would have been drinking alcohol throughout his stay on the Mens Scapus in order to avoid the parasites and pathogens in the barrels of stored drinking water. Unless, you know, he magicked it, but even then the others wouldn't have reacted as such, because the consumption of alcohol would have been a culturally accepted and normal thing and acknowledged as necessary for survival for all sailors regardless of age.
• Attack of the 50-Foot Whatever: A kraken attacks the ship in chapter 24. It turns out to be a manifestation of the Atlantic Ocean itself, stirred up by what appears to be Gideon's bad magic. Once Dipper extracts it, the ocean returns to a more calm state.
• Ballroom Blitz: It's a political meeting alongside a far less pretentious type of party, but the same principle applies. In chapter 18, every pirate crew allied with the Pirate Council convenes in Nassau to socialize and discuss the concerns of the day, and Dipper and Bill attend hoping to find information about Gideon's location and destroy any prestige Gideon has built off of supposedly killing the Demon Atop the Sea. No one is allowed to bring weapons into the gathering, so naturally those that have secretly sided with Gideon reveal they snuck in weapons halfway through. Chaos Ensues.
• Be Careful What You Wish For: When Ford goes off about how irresponsible it was to let Dipper out of the house and starts listing new restrictions to put Dipper under (including magically binding Dipper to the ship), Stan objects, arguing that Ford is going to end up pushing Dipper away. Ford, in a moment of anger and frustration, says he doesn't care. Neither are aware that Dipper is listening, and Dipper indeed runs away from home immediately after.
• Berserk Button: Bill's inner "beast" commonly manifests as out-of-control murderous rage originating as protective anger; the times when it's surfaced have all been in response to threats against those he cares for. Of the three "beast" appearances actually known in any detail, one began when pirates threatened Bill's brother, one was provoked but averted after Robbie attempted to sexually assault Dipper, and the most recent was the result of Blind Ivan back-handing Dipper across the face for daring to speak to him like an equal.
• Bittersweet Ending: It's not the ending of the story, but an ending, specifically a conclusion to a tension and conflict Stan and Ford had been experiencing long before this story began. The two love to travel the surface world and have had many adventures, good and bad, but gave up their traveling years ago to create a steady home in Gravity Falls to raise and protect the newly-orphaned Dipper and Mabel. Though they dreamed of returning and wanted to show Dipper and Mabel the world, they increasingly favored protecting the younger twins over teaching them - with disastrous personal consequences. Stan and Ford finally achieve their dream and get to return to the surface, and even get to show Mabel the sky, the stars, and the world out of the sea - but it's a direct consequence of them driving Dipper away due to their controlling policies and "near constant supervision" that, due to personality and interest differences, disproportionately affected him over Mabel. Their chance to share their interests and experiences above the sea with the younger generation wasn't taken until only Mabel remained for them to share with, the younger twin who actually vocally craved that having fled. Their actions conclude a chapter of their own lives, but set in motion Dipper's main story and the consequences of a conflict that they themselves stirred up twenty years ago.
• Black-and-Grey Morality: Dipper, Bill, and Gideon form a sliding scale of morality from light grey to black:
  • Dipper is kind and generally against killing but limited in his empathy for humans, self-describing to Robbie as "indifferent" to their lives (though he seems to develop out of this the longer he's around humans).
  • Bill is a mentally unstable pirate who slipped into nonchalant murder and thievery, and, despite his beginning to move away from that moral cliff edge, still has no qualms about killing the people he feels he has to for survival. He's characterized like a particularly paranoid and jaded Robin Hood that has wavered around his initially noble intentions.
  • Gideon is a megalomaniac who can control people like puppets and seeks to be the most powerful pirate captain "in all worlds," cheerfully slaughtering any and all in the way of his attaining power. Kept "offscreen" as it were, Gideon is only heard about from sycophantic followers who themselves seek to murder and destroy; the only active presence Gideon's legion has had so far—besides mutinying against Bill—is breaking the no-arms treaty of the pirate council and attempting to kill all of the communities' leaders. This makes him a villain even by the pirates' standards.
• Brought Down to Normal: Downplayed. When Dipper takes on a human form after leaving his Mother Waters, he becomes just as vulnerable at sea as any human, though he still maintains his natural magic.
• The Captain: Bill. Gideon ranks up to this on his own ship after his mutiny at the opening of the story.
• Cool Boat: The Mens Scapus, one of only five like her in the world, three of which have permenantly sank.
• Crossdressing: Dipper is talked into disguising as a woman in Port L'Orient and goes along with it mostly because he really likes the dress.
• Dangerous Eighteenth Birthday: If the implications in Stan's and Ford's conversations are an accurate interpretation of the "prophecy," Mabel's and Dipper's eighteenth birthday heralds the coming of some terrible event that could cause Stan and Ford to lose one of them forever. Notably, their eighteenth birthday occurs soon after this, and is a day of numerous firsts that may turn out to be harbingers of danger: it's both the day Dipper divines Gideon's location, setting up the long-awaited showdown with Gideon's crew, and the day Dipper becomes officially romantically and sexually involved with Bill, who is very likely connected with both the prophecy and the demon "Cipher." It's also the day the crew of the Stan O'War discover Dipper's current destination, setting every side of the main conflict up for collision in the Ionian Sea.
• Dark Secret: Subtle hints throughout the story clue the reader into parts of the past Stan and Ford have not shared yet. These imply a connection that dates back twenty years between Stan and Ford, the demon "Cipher," the Infinity Journal's author, Bill's Disappeared Dad, and the almost-certainly-not-accidental deaths of Mabel's and Dipper's parents and grandparents. The consequences of this dark secret are the implied cause of The Prophecy and Dipper's and Mabel's Dangerous Eighteenth Birthday.
• Dating What Daddy Hates: Ford spent much of Dipper's childhood impressing upon Dipper that humans are dangerous and that pirates are the worst sort of humans. Unbeknownst to Dipper, Ford is also desperately paranoid regarding a person named Cipher. Dipper's first lover is a human pirate captain named William Cipher.
• Deal with the Devil: Deals with Davey Jones and similar entities apparently exist in this world; Bill is accused by the Blind Eye Society of making one at the cost of his soul to survive the sinking of his ship. Subverted in that Dipper claims such deals are uncommon because human souls, unless used up immediately, are often dangerously unstable and more a burden than they're worth; Davey Jones in particular rarely deals for one due to the problems with storage and upkeep. It's probably not a coincidence that the accusation bears similarities with the plot of a certain franchise.
• Decomposite Character: Bill Cipher, the antagonistic demon of the Gravity Falls series, has his character split into what appears to be two separate characters: the more affable Chaotic Neutral characterization most fans attributed to Bill post-Dreamscaperers is given to current Pirate Captain Bill Cipher, secondary protagonist and Dipper's friend and eventual lover. The more malevolent characterization of the second half of the series, complete with making prophecies, threatening the lives of the Pines family, and inspiring paranoid tension in Ford, seems to be embodied by "Cipher," a mysterious demon whom Ford fears that may in fact be connected to Captain Bill Cipher, although it's unclear how right now. This character overhall has the benefit of adding a considerable amount of depth to Bill's character.
• Easy Sex Change: Initially played straight and then subverted. Dipper is male in gender but was born physically female. Among sirens, this is no big deal, especially since Dipper is so talented at magic: having studied siren anatomy, making adjustments magically so that his body matches his gender wasn't too difficult for him. However, this is subverted after Dipper has to drop his personal spells to focus on the extremely complicated spells he has to perform while raising the Mens Scapus and transfiguring both the fish school and himself into humans. This makes Dipper's body default back to female during the transformation, and since he has yet to learn enough about human anatomy to know what to safely change or how, he has yet to change his body's sex back to matching his gender.
• Evil Mentor: Played with. Bill is a murderer and a pirate with scores of lives on his hands, but he does have Dipper's best interests at heart and actually doesn't want to lead Dipper astray of his own morality. Bill teaches Dipper to fight because he knows that Dipper will need it to survive, but Bill is jaded enough about the world and himself to not want Dipper to be like him.
• Extraordinary World, Ordinary Problems: In an offhand remark, Dipper indicates that, contrary to what others may have heard, Davey Jones actually rarely deals for souls due to problems with storage and upkeep. This is particularly ironic, given that, in terms of folklore, Davey Jones is the only demon specifically associated with his own actual storage space (his "Locker," an old seafaring euphemism for the seafloor where dead sailors rest).
• Fear of Thunder: Both Dipper and Mabel are strangely terrified of storms and, in particular, the sounds of thunder that accompanies them. Both associate these booms and crashes with unexplained fear and anxiety and other terrifying sensations like "the sounds made by wood breaking and people screaming, the only sounds they could hear the night-" (Mabel cuts herself off here). Given the extremely questionable validity of Stan's and Ford's story that Mabel's and Dipper's parents and grandfather were killed by killer whales and the implication that they were actually killed by pirates pursuing Stan and Ford, it's possible this fear may actually derive from the sounds of cannon fire and battle as their family was slaughtered, though they were too young to fully remember and understand the situation.
• Friendly Pirate: Gideon and his men aside, most of the pirates in the story are Affably Evil at worst, Just Like Robin Hood at best. The Pirate Council refers to itself as "Organized Piracy" a la the more modern idea of organized crime, and doesn't seem particularly hostile to most. Some of them have been known to aid towns in crisis in exchange for places of safe harbor.
• Funny Schizophrenia:
  • While Bill exists in a time before psychiatrists and thus does not have a formal diagnosis, and while the underlying causes are probably supernatural rather than entirely mundane, many of Bill's symptoms would probably get him diagnosed with some kind of mood or personality disorder under the umbrella of schizophrenia, although rarely does any version of schizophrenia manifest with violence like Bill's. It should not surprise anyone, therefore, that this story averts Funny Schizophrenia hard: rather than causing anyone humor, Bill's apparent mental illness causes him to fear those around him will flee from him should they find out about his issues, and his inability to function in normal society for a consistent duration is the very reason he's a pirate. Bill's very much characterized as a Reluctant Psycho, and while he's incorporated his reputation for fearsome mental instability into his charismatic facade for the sake of his survival, his inability to always be in control of himself is in no way played for laughs.
  • The lack of humor in the situation is actually lampshaded in chapter 18. After Bill suddenly gets out of a long bout of depression and perks up to the point of mischievously poking and prodding Dipper about the ship—a significant and rapid change in mood and behavior, as while personal space has never really been a thing between them, it's usually Dipper who instigates the contact—Dipper jokes that he's finally come to understand Bill, that "when you’re not moping, you’re insane!" Bill immediately flinches, defensively asks “Yeah… I am insane, what’s it to you, kid?” and doesn't relax again until Dipper, aware that he's accidentally caused harm, makes clear that the comment was intended as one of the many teasing quips they exchange between them and that he's glad he's finally getting to see Bill when he's happy.
• Gratuitous Latin: All of the magical spells used by humans and non-humans alike are spoken in Latin for some reason.
• Hearing Voices:
  • Bill hears a voice that constantly sasses and disagrees with him. While this and other unusual behaviors of Bill's mimic some kind of mental illness, it's unclear to what extent these symptoms are mundane or magic. The voice in particular talks like an entity very independent of Bill and self-aware that it "inhabits" him. At one point, it threatens to possess his "vessel" out of frustration; however, it doesn't appear to mean him harm, instead expressing the desire to keep Bill stable, claiming it's only staying with him to keep him from falling apart out of "love," and its major problem appears to be Bill's self-destructive behavior. It also appears to ship Bill and Dipper.
  • It also implied that it "visits" Tad, and that Tad just never said anything about this. If this is true this would confirm the voice's supernatural rather than entirely psychological nature; however, we as of yet have no proof of this claim—if the voice itself is a mundane symptom of Bill's health issues, then any claims such as this could equally be so.
• Hereditary Curse: While it's dubious whether it's a curse, if the implications about the Infinity Journal's writer being Bill's father are true, Bill's inhuman traits are actually something passed down from parent to child. This also opens the possibility that these unstable qualities are the force that drove the journal's writer out of both mind and humanity.
• Historical AU: Gravity Falls takes place in the 2010s, whereas the fic takes place near the tail end of The Golden Age of Piracy, or the 1710s.
• Historical Fantasy: The story basically takes place in The Golden Age of Piracy, except All Myths Are True.
• Humanity Ensues: Dipper (and later, his siren family) uses magic to assume the form of a human and sail on the Mens Scapus as Bill's first mate. The adjustment is difficult. On the other hand, Dipper offers magic to a school of fish if they will transform with him and become the ship's crew, and they, he petulantly notes, seem to have no problem.

• Humans Are Special: Refuted hard. Dipper appreciates many of the experiences of the human world but spends quite a lot of time riffing about the disgusting ways the human body functions and the more nonsensical elements of human society. The aspects of humanity usually deemed "special" with this trope are just as commonly found among non-human characters.
• Humans Through Alien Eyes: Dipper is a Fish out of Water that had never met a human before Bill, and his only knowledge of them comes from his great uncles' stories. This leads to a major Culture Clash as Dipper struggles to interpret the whats, whys, and hows of human life and adapt enough of them to pass for a normal human. This is not helped by the contemporary humans' limiting views on gender identity and sexuality, which Dipper defies through his very existence.
• I Just Want to Be Free: Dipper dearly and sincerely loves his family with all his heart, but can't stand the sudden control complex they've developed over his life—to the point where he willingly fled home with a pirate, the type of human Ford described as "the worst," just to escape the Implicit Prison his family intended his life to become.
• Implicit Prison: Stan and Ford feared a danger they refused to warn Dipper and Mabel about would come and take one of them away forever around their eighteenth birthday, and so issued ever-more controlling policies to try to prevent anything happening to them. Due to differences in personality, life style, and interests, these limitations grossly effected Dipper more than Mabel. While Mabel's daily life appears to have been generally unchanged, Dipper's education was suddenly stopped and he was put under virtual house arrest and "near-constant surveillance" due to his natural curiosity and unwillingness to stay cooped up for long durations. To Dipper, Stan and Ford one day began treating him like a criminal under prison sentence for seemingly no reason. Once Ford pushes this to even further extremes and threatens to magically bind Dipper to the shipwreck they live in, this settles Dipper's mind on the matter. He flees.
• Internal Reveal:
  • Dipper's and Bill's stop at Nassau reveals to the majority of the pirate community that Bill's new first mate is an inhuman being powerful enough to summon god-tier entities unseen for thousands of years. Depending on how many of Gideon's followers escaped and what they learned before they did, Gideon now likely also knows.
  • Mabel's bout of Twin Telepathy in Chapter 21 finally clues the Pines in to the fact that Dipper's disappearance may not be the kidnapping they assumed.
• I Owe You My Life: Played straight with Bill, who feels he owes Dipper for saving him from drowning when the Mens Scapus went down, for fixing his ship, and for giving him the means to reclaim his crew. Played with in terms of Port L'Orient; though Bill saved the town from perpetual zombie invasion, he initially treats the villagers owing him their lives as a joke—however, he does expect basic respect in turn for his deeds, and is genuinely angered and betrayed when certain individuals within the town reveal themselves to be disrespectful towards those under his protection or to have intentions of treachery against him.
• In Medias Res: The story opens with Bill tied to the mainmast of the Mens Scapus as it sinks to the bottom of the Mediterranean Sea.
• Informed Attribute: Dipper and Bill regularly discuss how closed-minded humanity in general is and how hostile they may be to discovering various facets of Dipper's identity, particularly regarding his sexuality and gender—but while this was definitely true during this particular time in history and even true today in many parts of the world, we don't really see a culture-wide discomfort with Dipper as a person within the story; everyone who finds out is generally quite respectful of Dipper's gender identity. After over a dozen chapters, at least four visits to port, and the introduction of a fairly substantial cast of human side-characters, the most we see of this close-mindedness is the misogyny displayed by two members of the Blind Eye Society, and two people can hardly be argued to speak for entire cultures or entire species.
• Innocent Prodigy: Dipper's a bit older than most examples, but fits quite well: he's still rather naive about the world and ignorant as to his own place in it—even as to just how much of a prodigy he is. Along with his prodigal analytical skills, he's extremely naturally gifted with magic.
• Insane Troll Logic:
  • After hearing word that a shipwreck possibly previously crewed by human pirates was raised from the seafloor around the time Dipper disappeared, Ford falls to Theory Tunnelvision, and, from only three pieces of information—pirates possibly in the area, a ship recently sank and then was raised from the seafloor half a day later, and Dipper disappeared around this time—Ford concludes definitively that Dipper is being held prisoner by pirates on that formerly sunken ship. This conclusion completely ignores a lot of the actual evidence surrounding said disappearance, like the fact that it was well known that Dipper was chaffing under the living conditions forced upon him by Ford, and that Dipper clearly came back home in secret right before his disappearance in order to gather materials before leaving again, as if knowingly preparing not to come back. Ford's theory also ignores that while there is evidence that Dipper left of his own volition, there is no evidence whatsoever that Dipper is or ever was anywhere near the sunken ship, or that anyone survived the sinking of the ship, or even if anyone went down with the ship in the first place, let alone that Dipper had somehow been kidnapped by these entirely hypothetical survivors. Given that it's explicitly stated that magic is uncommon and comparatively weak amongst humans and that no human can see the future, it's also just flat-out completely insane to believe without evidence that these hypothetical human pirates stuck at the bottom of the ocean coincidentally were already prepared for successfully battling and capturing an extremely powerful and magical siren during the wrecking of their ship and for somehow restoring their sunken ship to the surface while simultaneously trying not to drown at the bottom of the ocean for eleven hours straight after the story went out of its way to demonstrate how clumsy humans are in the water even when they're not drowning. But what other answer could there be? Even the semi-accuracy of their assumption is astonishing considering how little evidence they used to get to it. The more obvious and evident solution is that Dipper ran away, and if they really wanted to connect him to the sunken ship with no evidence, Occam's Razor would imply that Dipper, the only confirmed magical entity in the area at the time, may have used the recently sunken ship as his escape, especially since he came back and took the magical materials necessary for serious magical work with him; no phantom impervious-to-drowning siren-capturing magic pirates necessary. But instead of seeing the more obvious and likely explanation (one Stan even warned might happen if they confined Dipper too strictly), the Stan twins appear to have heard the word "pirates" and turned their brains off.
  • This has tragic consequences on the Pines family's search for Dipper. Because they assume Dipper is a prisoner and thus that he is likely never allowed above deck or off the ship, they don't bother to ask if anyone's seen him at any of the ports they visit and only have a vague, likely incorrect description of the ship he's thought to be on. This means that even if they go to a port that the Mens Scapus had moored in and talk to people Dipper interacted with personally, they still don't know enough about the situation to even ask the right questions or recognize significant information when they hear it. Until Mabel has her Twin Telepathy vision, their search was functionally dead in the water.
  • Possibly Justified by the later implication that Ford has a history with pirates and believes that the nonhuman pirate he has bad blood with, "Cipher," will somehow come after one or both of the twins around their eighteenth birthday, a date only a month after Dipper's disappearance. Knowing this, it's easier to understand why the word "pirate" in any association with Dipper's disappearance triggered Ford's paranoia and caused him to jump the gun, because under the assumption that Ford's Cipher is responsible, the power and planning required to do all of these ridiculous things intentionally is suddenly feasible. It's still an irrational leap in logic regardless, as there is no evidence that any of the above actually happened or is even connected to Dipper's disappearance, but it's made more understandable by Ford's history and fears.
• It's All About Me: What little we hear of Gideon implies that he basically thinks he's the main character, almost literally considering he assumes the prophecy is about him. Whatever he's searching for, he thinks it will make him the "most powerful captain... in all worlds."
• Journey to the Center of the Mind: Just like in canon, Bill possesses the ability to bring people in and out of the Mindscape and alter their dreams. Unlike canon, his only demonstration of this ability so far is for the purpose of helping Dipper overcome his night terrors.
• Just Like Robin Hood: Bill describes that during his crew's slow transition from tradesmen to pirates, they began targeting and pillaging the corrupt. It's implied they drifted away from those vigilante ideals by the time the story began, given Bill's internal monologue in chapter 1.
• Loveable Rogue: Bill, who is characterized less like an unfeeling monster and more like a Noble Demon.
• Million to One Chance: Former Mens Scapus First Mate Gideon Gleeful was very thorough in his plan of mutiny, turning members of the crew against Bill of their own free will, using his Mind Control bolero over the crew that wouldn't submit, and even arranging an alternative vessel just so he could spitefully have the ship go down with her captain. In Bill's own words, he "left no error." So naturally Gideon kicks off the plot by just happening to pull off his perfect coup literally on top of possibly the only benign creature in the all of the waters they've sailed in with both the willingness and ability to save Bill and his ship.
• Morality Chain: What Dipper is to Bill. Bill's told Dipper outright that he won't be a good example for a "kid siren," but the fact that Dipper actually trusts him to be a good man regardless seems to drive him to watch his actions and emotions more so as not to scare Dipper off. While this trope is downplayed when Bill's in his right mind, it's in full force when Bill's more unstable emotional state emerges during his Rage Breaking Points, as Dipper's mind-altering siren song is the only thing able to entrance Bill enough to neutralize this state.
• Names to Run Away from Really Fast: "The Blackness from the Stars." Luckily, it typically doesn't give a damn about the mortal world, and has ignored every attempt to summon it for thousands of years. Horrifyingly, it doesn't ignore Dipper's.
• Never My Fault: When Stan lets Dipper out of their home for the first time in a month—ostensibly to do chores, but really out of pity for how being cooped up was affecting the boy—Ford becomes angry and lists a whole bunch of new restrictions to put Dipper under, despite Stan's caution that further restrictions will push Dipper away. When Dipper is reported missing just hours after this conversation, Ford immediately insists that Dipper was kidnapped by pirates and denies that Dipper could have left of his own free will.
• No Celebrities Were Harmed: In chapter 18 the crew of the Mens Scapus head to Nassau to convene the Pirate Counsel. As this appears to be during the decade that Nassau was literally run and ruled by pirates (1706-1718) and the story's human culture has so far politically paralleled the real world (except for the fact that All Myths Are True, which is minimally invasive as most of said myths do their best to avoid human attention), it wouldn't have been unexpected for a number of prominent pirates from the age to make cameos in such a counsel. Instead the only two named pirate captains are original characters, and while some others appear vaguely reminiscent of historical figures, no historical identities are specified by name.
• Noble Demon: Bill, possibly literally and very ironically given his role in the show's canon. Bill is a pirate—a murderer, thief, cutthroat and renegade. Yet he has a depth and underlying softness to his character that reveals a certain amount of virtue despite these qualities. A lot of what makes Bill sympathetic despite his occupation is his acceptance and respect for others, regardless of sex, gender, sexuality, race, or species, which is heavily contrasted with the misogyny, racism, homophobia, and general bigotry of the general population. Due to his role and the way his life has gone, he's seen the worst of humanity and is disgusted by humanity's cruelty towards themselves and others, though very self-aware about how terribly cruel he himself has become and can be, and very jaded regarding the concept of innocence. He gradually shifted into the pirate role due to circumstances and necessity, rather than original criminal intent. Bill ultimately comes across as a decent person who ended up a pirate due to necessity for survival and thereafter slowly adapted to the more cruel pirate lifestyle and mentality. On top of this is the heavy implication, given how he describes the change as gradual while talking self-loathingly of his fellow humans and his own behavior, that Bill looked at the people he'd ended up with, looked at how the world saw them, looked at how they and other humans treated each other, and just gave up on the idea of being good.
• No Name Given: The exposition during the Pirate Council is entirely about a specific and controversial pirate who disappeared some twenty years ago and once wrote a prophecy about how the Vagueness Is Coming in a book he left behind. Everyone seems to know who this is but no one ever gives his name, making the conversation about him both extremely unnatural-sounding and extremely difficult to follow. Even the details people shout out about him are contradictory, with some insisting he's a hero who died to warn others and others insisting he turned into a monster—quite literally. It is made fairly evident that there is a connection between this unnamed pirate, Ford's mysterious former friend Cipher, and Bill's disappeared father.
• No Periods, Period: Averted. Dipper, having taken the form of a physically female human, does experience a period, and just adds it to his reasons for why being human is awful.
• No Sense of Personal Space: Sirens in general are like this, according to Dipper. Sirens, being very social creatures who live in relatively cold environments, use physical contact to share heat and maintain a sense of emotional security. Dipper, unused to the concept of personal space, begins the story pretty constantly in physical contact with Bill; Bill eventually opens up enough to reciprocate and even instigate the contact. By the time they become romantically involved, they're a Cuddle Bug Couple.

O-Z

• Our Mermaids Are Different: the Sirens in this story seem to be a fusion of merfolk and siren folklore; though the sirens have the classic Compelling Voice, the sirens are closer to a benevolent merfolk archetype then the predatory nature hinted at by the label "siren"—with most outright avoiding humans and the surface altogether. Also, many seem to mimic the forms of different aquatic species ranging from octopi to sharks. They're also naturally magical creatures and can thus perceive the different kinds of magic in the world through their normal senses. A limited number are capable of wielding magic beyond their voice and senses, though these seem to be few in number.
• Our Sirens Are Different: Dipper is one, as are the rest of the Pines family. Unlike most versions of sirens, Dipper's pod and town do not use their voices to lure humans; in fact, the sirens prefer to live far away from humans and the shore to the point where it's very rare for humans to encounter them. Given the rarity of its use on humans, that Ford is the one who taught the twins, and that sirens make note of which sea species are immune, it's possible the Compelling Voice's intended function may instead be a defensive ability against predators in the ocean.
• The Pirates Who Don't Do Anything:
  • Played with. Characters talk quite a lot about the pirating Bill has committed prior to the story, but due to the focus on hunting Gideon, none of that has so far gone on during the story proper. The characterization of Bill in the first chapter sounds far more like a pirate than the softer character we see him be around Dipper and Rezin.
  • The Pirate Council in the story act more like a gathering of small mafia bosses than pirates: they've formed a paralegal governmental structure applying to all the captains under their allegiance and have power to the point where even the majority of those who aren't under their control do not dare to interfere with their policies; they've also created their own laws and do not abide by those of the official local governments. They are criminals, but they act like a confederacy of organized crime families under the leadership of their captains (the bosses). Neviah, current Praesul of the Council, even refers to their brand of piracy as "Organized piracy." Notably, the "bad" pirates are the ones that rebel against even pirate laws. In Real Life, the European colonies-centric pirates of the Golden Age did have their codes and laws, but they were usually only agreed upon between members of a single crew or temporary fleet as each man's conditions of service. The story possibly justifies this difference between real pirates and the pirates in the story by implying a major disruption in the pirate community changed the course of events during the beginning of the Golden Age and led to the formation of the first version of the pirate council, thereafter creating more a widely applicable code amongst pirates in general.
  • What we hear of Gideon since he mutinied against Bill completely subverts this trope entirely: he's invaded, slaughtered, and looted towns; acquired ships; ordered the attack on (and attempted murders of) the Pirate Council and its allied captains; and seeks to be seen as "the most fearless and powerful captain to sail the seas of this world... of all worlds.”
• Plot-Based Photograph Obfuscation: It's not a photograph, but the stained glass window in the captain's quarters on the Mens Scapus has been mentioned repeatedly in significant character moments, yet each time alludes description beyond a vague connection to "some prophecy." Considering everyone and their grandmother has repeatedly mentioned some ambiguous prophecy, particularly in relation to Dipper and Bill, it's not a stretch of the imagination to conclude that the contents of the stain glass image are plot-relevant and revealing.
• Port Town: Given that most of the story takes place on the sea, a port town features any time the Mens Scapus heads to land. Unless something plot-significant happens while they're in town, it's hardly glanced over—the two major ones named so far have been Port l'Orient (in France) and Nassau (Bahamas). A third unnamed port features in Chapter 17, described only as "off the coast of the Pearl Keys," which would place it east of Nicaragua. Port L'Orient crosses into Not-So-Safe Harbor, given just how much conspiracy and exploitation was going on there. Gravity Falls is kind of an inversion of this - it's a town beneath the sea, rather than beside it; an offhand comment by the Grunkles imply that it does trade secretly with a few select surface communities.
• The Prophecy: Multiple individuals have discussed a "prophecy" at varying points. Bill offhandedly mentions that one is visually depicted on a stained glass window in the captain's quarters, First Scale fondly implies that she knows one relating to Dipper's and Bill's relationship, and Stan and Ford imply knowledge of one during their conversations when searching for Dipper. The only instance of any such prophecy being given in full for the reader is during the Pirate Council meeting at Nassau, in which the Praesul presents two passages supposedly predicting the future that were written by a conspicuously unnamed pirate twenty years ago. It should be noted that though this is called a prophecy, the actual passages, when paired with the name the passages are addressed to, read more like a promise of revenge, or a curse. The prophecy seems to have been written for Ford and to be about some sort of revenge the writer will enact upon his "lass" after a period of eighteen years. It's heavily implied the writer may be Bill's father.
• The Quest: Dipper and Bill agree to travel together to hunt Gideon and rescue the loyal members of Bill's crew. Unlike most versions of this trope, this is heavily implied to be something of a Red Herring plot, as a more important conflict seems to be lingering just on the horizon—that being the origins of Bill's demonic aspect and the curse/warning "Cipher" gave Ford presumably about Mabel or Dipper.
• Rage Breaking Point: Blind Ivan should not have slapped Dipper. Hurting someone Bill considers his Protectorate, especially in such a deliberately demeaning way, guarantees his Soft-Spoken Sadist side will come out.
• Rape, Pillage, and Burn: What Gideon and those who willingly follow him have been doing to everyone they come across. Bill as a pirate is confirmed to have done the "pillage and burn" parts, but it's described in Robin Hood-style so it's unclear if the third ever happened on his watch.
• Red Baron: Though Bill doesn't use it often, he claims he's known as "the Demon atop the Seas," as opposed to Davey Jones, who we learn is the Demon beneath the seas. References to his "demon" nickname are made by characters throughout the story, and become increasingly ironic as the story progresses.
• Red Eyes, Take Warning: Bill's eyes normally have blue irises and white sclera, but when "the Beast" makes a show of things, his sclera turns black and his irises flash between white and red, emphasizing his Ambiguously Human nature.
• Red Herring: Dipper assumes from meeting Bill that some humans have natural, innate magic, and the perspective choices in the first dozen chapters lean towards implying this to be true: Bill's perspective when describing magic at times mirrors Dipper's, implying that magically inclined humans can also sense magic. However, after seeing Bill's "beast" naturally use an instinctive kind of magic to paralyze the Blind Eye Society, we learn that humans do not have innate magic, should not be able to sense magic like Dipper does, and that those humans that use magic have instead learned to manipulate magic around them—and thus, that Bill's magical perceptiveness as described is actually demonstrative of innately inhuman qualities. Because Bill was the only human magic user character prior to this point, the reader is mislead by Dipper's assumptions on how human magic work and Bill's assumption that he is 100% human.
• Reluctant Psycho: On the surface Bill appears to revel in his fearsome and intimidating reputation as the Demon Atop the Seas, but it's heavily implied this trope is more accurate of Bill underneath his veneer of careless suave. We find out during the events at Port L'Orient that not only does Bill have very real mental health issues that have essentially hijacked control of his life at many instances, but that Bill has spent the entirety of the story so far trying to downplay and hide these issues so as not to scare Dipper off.
• Reports of My Death Were Greatly Exaggerated: But not by much! When Bill went down with the sinking Mens Scapus while tied to her mainmast, all present thought his death was so thorough and assured that they spread the word of his death far among the pirate community. As such, pretty much everyone who sees Bill is stunned that he's alive, and their reactions range from hysterical laughter to literally thinking he sold his soul in a bargain with Davey Jones.
• Role Swap AU:
  • In Gravity Falls, Bill is a powerful supernatural creature offering to make deals that further his own ends, while Dipper is a far less powerful mortal that Bill makes a deal with and takes advantage of; Bill is perpetually the one with greater power. In Drowning, Bill is a human? in the process of literally drowning, and Dipper is the ridiculously powerful supernatural creature that saves his life and offers him a ship, crew, and return to the surface—on Dipper's terms and conditions, of course. They haven't swapped dispositions, only power dynamics; Dipper is still compassionate and Bill's still mentally unstable.
  • Similarly, if the implications about Bill's father being both the conspicuously unnamed pirate who wrote the prophecy and a Decomposite Character of canonical Bill Cipher are true, then he and Ford are also this, At the time they appear to have met and collaborated, Ford was a supernatural creature who shared information on magic and the supernatural with his curious human friend, and Bill's father was a rougish human who left behind a journal of dark and mysterious research, whose work is unfinished, whose identity outside of his authorship of the journal is mysterious, and whose ultimate fate is unknown but implied to be grim—which is the opposite of their roles in Gravity Falls (wherein Cipher is the magical mentor and Ford the mysterious unnamed author whose work is both ominous and unfinished). Like Dipper and Bill, however, they've generally kept their canon dispositions.
• The Runaway: Though his family are certain (without very much evidence) that Dipper has been kidnapped, in reality he fled their oppressively controlling home environment.
• Sealed with a Kiss: Averted. Dipper and Bill attempt this to seal their pact to accompany each other through to their goals, but they're interrupted by the Blind Eye's Boarding Party.
• Self-Fulfilling Prophecy: Stan and Ford are terrified of a "prophecy" that they believe foretells that they will "lose" one of the younger twins around their eighteenth birthday (with the subtext implying that this twin will be doomed in some manner), a prophecy heavily implied to somehow involve the Cipher family, given the likelihood that the prophecy was made by Bill's father. This drove them to become increasingly controlling and limiting towards Dipper's and Mabel's freedoms in a manner that disproportionately affected Dipper's interests and activities, leaving Dipper under-educated in the use of his magic, ignorant of the danger possibly looming, and under virtual house arrest and "near-constant surveilance" due to how little Ford trusted him with his own freedom. Ford's frustrated exclamation that he was going to magically imprison Dipper after Dipper is slightly late returning from a chore in the coral fields—the one bit of freedom Dipper had been given in a month—becomes the final straw, driving Dipper to flee from them straight into the companionship of Captain Bill Cipher, whom Dipper coincidentally saved from drowning while he was out. Stan's and Ford's controlling policies that were intended to keep Dipper safe from danger are the very thing that jumpstarted the danger they feared, and further, have left them largely distrusted by Dipper with no way to protect him; they are now desperate to get him back before something likely Cipher-related befalls him.
• Shapeshifter: Dipper's explanation of the magic he uses to alter his body and its limitations imply that he is, on some level, this. Dipper explains that his ability to alter his body is reliant on a knowledge of anatomy regarding the form he wishes to take, which is why he cannot shift into a male human form after his transformation defaults him to female. By this logic Dipper could use magic to take other forms besides human and siren, should he study their anatomy thoroughly enough.
• Shipshape Shipwreck: The story's averting of this is a plot point. Despite only having sunk a few hours prior, the Mens Scapus is in absolutely terrible condition by the time Dipper and Bill return to repair it, with its masts and hull broken, the keel—its foundation—suffering what would normally be permanent damage, and its timber and ropes swollen into conditions that would have been utterly unsalvageable by mundane means. Without rare and powerful magic, it would have been a total loss. Its destruction is so complete that Bill's survival and the raising of the Mens Scapus was thought impossible, and it's only due to a chance Spanner in the Works that the ship and Bill weren't doomed to wreck and watery grave there and then.
• Shout-Out: Blind Ivan assumes that Bill and the Mens Scapus returned from the bottom of the sea via Bill selling his soul to Davey Jones (an idea Dipper finds to be utterly ridiculous).
• Sickeningly Sweethearts: Subverted. Dipper and Bill were already very affectionate before getting together and are very affectionate afterwards, but the only people around to react are the fish crew who tend to think they're adorable—especially Soos, who's an open romantic.
• Sinking Ship Scenario: The In Medias Res Cold Open of the story begins with this, as Bill and the Mens Scapus sink to the bottom of the Mediterranean sea.
• Sirens Are Mermaids: Dipper and his kind are portrayed more similarly to the folklore of merfolk, except with Compelling Voices.
• Slowly Slipping Into Evil: Bill pre-story began his career at sea as a merchant, then turned to vigilante pirating when his apparent mental illness made him too unstable to conform to the right side of the law, and from there is implied to have sunk further and further away from any real moral justification for his actions as he slowly gave up on the idea of human morality altogether, even within himself. Judging by his internal narration in the first few chapters and his shame at his previous actions in later ones, he seems to have been on his way to becoming a Misanthrope Supreme before Dipper began pulling him away from the cliff edge.
• Small Role, Big Impact: Someone named "Cipher" had a very negative encounter with the elder Pines Twins back when they sailed the ocean's surface on the Stan O'War two+ decades ago. If this person is the same as Bill's father and the unnamed pirate who recorded the Siren prophecy, then despite having exactly zero appearances in the story so far, "Cipher" is responsible for at least a good half of the plot.
• Soft-Spoken Sadist: How Bill's "Beast" personality behaves: eerily quiet, unstoppable yet slow, and perpetually, silently, viciously enraged. When we see this personality shift from Bill's perspective, it functions like Bill's normal condescension towards humanity in general multiplied by his sudden spike of hate for those who attack the few he cares for, a suddenly exceedingly violent temper and lust for the suffering of those who have managed to make him snap, and the loss of all consequence-based inhibitions towards extreme behavior—all of which is accompanied by the instinctual realization in that moment that Bill has the power to make them suffer as much as he wants and they can't do anything about it. In his show-stopping appearance chapter, Bill's inner beast is characterized, above all, by an intense, violent stillness, punctuated by the squelch of human organs being forced into places and shapes they shouldn't. Bill in this state of mind is basically the homicidal version of Cold Ham.
• Stick 'em Up: A tree nymph working for Gideon tries to force Dipper at gunpoint to summon a monster, with the intention of forcing Dipper to kill everyone in the room through this. It doesn't work out exactly as he wished.
• Strong Family Resemblance: Bill is noted to have physically taken after his biological mother.
• Summon Magic: One of Dipper's talents, to his varying horror. In chapter 18, Dipper, with a gun pointed at his head, is forced to attempt a summons that will result in the deaths of all those around him. In his attempts to prevent this, Dipper instead recites the spell for summoning a different entity, a dark god that has refused to be summoned for thousands of years, planning for nothing to happen in an attempt to bide time and figure out how to defuse the situation. Instead, the entity he insincerely summoned, the Blackness from the Stars, actually shows up, devours the person pointing a gun at Dipper's head, and this terrifies the rest of the aggressors into fleeing for their lives. Dipper manages to keep his head in the immediate aftermath until the summoning book is destroyed and the danger has been mitigated, but afterwards is utterly shaken by the fact that he killed someone, especially via summoning a being that supposedly never answers.
• Sword and Gun: Bill begins to train Dipper to use these weapons early on in the story, believing he's probably going to need to fight when they confront Gideon.
• The Golden Age of Piracy: The story's most likely time period, though no specific years, dates, or concrete datable historical events are ever mentioned.
• Transformation at the Speed of Plot: For some reason, sirens are forced into human form when outside their "mother waters," an ambiguously-defined but small area of water that apparently excludes the Atlantic Ocean. Aside from contradicting Dipper's previous implications that he actively had to concentrate on the transformation and the many, many logistical questions of how this limitation would even function with sirens as a species (do sirens just drowned if they swim too far from home?), this means that Dipper cannot return to siren form until he returns to these Mother Waters and is therefore at risk of drowning just like any human. Oddly he still has access to his other siren abilities, such as his natural magic and Compelling Voice.
• Transplanted Character Fic: The story is basically the Gravity Falls cast transplanted into an All Myths Are True version of The Golden Age of Piracy.
• Traveling at the Speed of Plot: The two main protagonists do an incredible amount of traveling, none of which they have the actual time for. The Mens Scapus sails from the spot it sunk in the Mediterranean just off the coast of Africa, travels around Spain and Portugal to Port L'Orient on the Northwest coast of France, over to the Pearl Cays off Nicaragua in Central America, and up to Nassau for the meeting with the Pirate Council—all in what Dipper describes as a little over a month. In absolutely ideal sailing conditions at a consistent speed of about 20 knots—the top speed a 1700s vessel could go—it would take approximately 22 days to make it from the Mediterranean to Nassau via this route with absolutely no stops in any of the ports themselves. But the actual average speed of a ship at the time was 4-5 knots—more than four times slower—and the Real Life amount of time it would take to complete this route on a period accurate ship would be between three and five months (if no anomalous delays). Like with the biological impediments to Bill seeing, hearing, and speaking properly under the water, the travel time discrepancy is Lampshaded by Bill, who suspects that the magic Dipper used to fix the ship is also affecting her performance.
• Truth in Television: Nassau really was the pirate capital of the Caribbean for a number of years during the Golden Age of Piracy. Originally an English colony, a long period of ineffective governors, poor leadership, two French and Spanish occupations, and eventual abandonment by British authorities left Nassau in ruin and without a government by 1704. Predictably, this turned Nassau into a den of pirates. The big influx of power, however, didn't come until 1713, after peace was made between the English and Spanish and the war's Naval veterans were suddenly left to starve without work and often without financial compensation for their service. Turning to illegal methods to survive, government-free Nassau was flooded by former privateers and military sailors to the point of forming its own independent Pirate Republic in 1713, with the pirates electing their own leaders from among their number and, through this quasi-political union, managing to bring trade between New and Old Worlds to a near-total halt. The Republic came to an end in early 1718 when the British regained rule over the island and pardoned all who turned themselves in and promised to cease committing piracy; prior to that, the pirates were the government of Nassau and did as they pleased—the only "criminals" enforced against were those who broke the "Code of Conduct" (the pirates' code as defined by whichever pirate was governor at the time, because different captains had different codes).
• Twin Telepathy: Dipper's magic is powerful enough to have an echo effect that carries across to Mabel with enough strength that she can sense his emotions and occasionally what spell he's using. When Dipper divines Gideon's location using a searching spell that extends its power outwards across the entire ocean, it passes over the Stan O'War and Mabel is able to sense Dipper's results, allowing the Pines to figure out that Dipper is headed to the Ionian Sea.
• Underestimating Badassery:
  • Dipper in human form is described as quite small, rather pretty, and physically female despite his male gender identity. Given that this is the Golden Age of Piracy and neither women nor trans individuals were very highly thought of or even well understood, there have been occasions when characters are particularly rude or cruel to Dipper while operating on the assumption that he has no power to do anything about it. They would be wrong.
  • Bill takes the cake on this, having forgotten that Dipper was powerful and had power over him while Dipper was still in siren form. He takes his teasing a bit too far and forgets, due to how innocent and gentle Dipper acts, that Dipper is a powerful ocean predator who's literally the only thing keeping Bill alive at that moment. Dipper grabs Bill's head with both hands, locks eyes, and swiftly corrects him.
• Unskilled, but Strong: Dipper is a magical juggernaut. A largely untrained magical juggernaut, because for some reason Ford decided to stop teaching Dipper before completing his magical education. Bill, at least, suspects this is related to how abnormally powerful Dipper is, although why Ford would think it best not to train someone with that much power is still a mystery.
• Unstoppable Rage: Well, nearly unstoppable. Once Bill's provoked into "Beast" mode, those that provoked him usually end up brutally eviscerated—this is particularly true if the Beast was provoked by attacking someone Bill cares for. After smacking Dipper for daring to stand up to them while being "female," the majority of the Blind Eye Society was only spared because Dipper's Siren Song managed to enchant Bill into ceasing his attack. It's heavily implied that Dipper's magic is much more powerful than the average siren's, so it's unclear if another siren could even pull off such a feat.
• Vagueness Is Coming: The Prophecy written by the unnamed pirate is so ambiguously written that it could be interpreted as anything between a warning, a promise, or a curse. It changes time and person tenses, it changes speakers and perspectives without identifying them, and it never uses a proper noun, just flowery, ambiguous descriptions that may be metaphors or may be literal. There isn't even a consistent subject in the sentence structure, with the pronouns switching from second person to third person and masking exactly where it is in the sentences that the lines change who they're talking about. Who is the poem ordering about? Are they the same "siren" they address at the end, or a different person? Who speaks the quoted curse, and to who? When do the events in the poem even happen—has the first part already occurred, or is this scene under the ocean something that will happen later in the story? The poetic form of the prophecy exacerbates the confusion even further because, with the altered phrasing, the relationship between each line to the others is unclear. For example, the quoted curse isn't definitively attributed—it could be the monster or the spell-spinner speaking, which significantly changes the implications towards the identity of the target. Because of this ambiguity, it's possible to make equally decent arguments for the prophecy's subject being Dipper, Mabel, or even Bill. The poem is so unclear and unhelpful in communicating whatever it is its writer was trying to say that Gideon's followers even believe it's about him, and that it's actually foretelling that Gideon will be the most powerful captain in the multiverse. The obvious truth is that this poem is written only to make sense to someone who already knows the identities of the writer, the "monster," and the intended audience (whomever was supposed to be the unmentioned "you" clearly implied by the writer's various commands towards the reader). But despite the writer's identity having been heavily implied to be Bill's father and a surplus of suspects that could fit both for the "you" and the monster, the identities of those involved are still unclear, leaving the meaning of the poem a code without a key.
• Villain Team-Up: Inverted. Despite murderous pirates and sirens with Compelling Voices usually being the villains of stories, the whole plot of this one is that the pirate and siren that team up are the relative good guys.
• Was Once a Man: It's rumored that the unnamed pirate who founded the first Pirate Council and left behind a cryptic prophecy was somehow turned into a monster. That there is truth behind the rumor is made more likely by the fact that Ford apparently knew a human who did so, and the prophecy this pirate left behind was not only written in a journal identical to Ford's, but also addresses Ford in code.
• Water Is Air:
  • Bill lampshades how strange it is that he can talk and converse with Dipper after Dipper temporarily gives him the ability to breathe underwater—which should have, logically, affected the actual acoustics of their voices and made human-style linguistics almost impossible, as sound waves travel very differently in the denser water than in air and the human ear is not adapted to pick up sounds accurately in those conditions. Similarly, Bill can also see perfectly clearly while submerged in salt water, despite the human eyes not being adapted to the refractive indices of water and despite salt water generally being very painful for the human eyeball. Though it's never confirmed, there's always the out that these effects were tied in with the spell Dipper cast to enable Bill to breathe. It is actually implied that the merfolk's natural magic enables them to speak and sing like humans even under the sea, so the idea that some of these attributes would carry over in the temporary spell isn't that far of a stretch. Of course, the fact that Bill himself likely isn't entirely human and has his own natural magic may also contribute.
  • On the other hand, the story averts this trope in most other ways. Water pressure and temperature are mentioned and become concerns for the human's health (though oddly not nearly as much as they should have been), and the thermal vents on the ocean floor spew realistic heat, mud, chemicals, and nutrients that do mess with the water. Similarly, it's constantly lampshaded that Bill's body is not adequate for any sort of efficient movement underwater, much to his chagrin.
• Where the Hell Is Springfield?:
  • What does Dipper mean by his "mother waters"? Does he just mean salt water, the ocean, the Mediterranean, or a specific part of the sea that he lived in? We learn in Port L'Orient that Bill's ship went down off the North coast of Africa, presumably putting Dipper's siren colony in the Mediterranean. After divining Gideon's location to be in the Ionian sea, the crew are described as eager to end the journey and return to their Mother Waters. Does this mean that the Ionian sea (which is a part of the Meditteranean) is part of their Mother Waters, or is it simply referring to the fact that they will get to return home after catching Gideon? Chapter 24 introduces the Atlantic Ocean as a character, whom Dipper describes as "like his Mother Waters." As this appears to refer to bodies of water, this could mean that Dipper's "Mother Waters" are the Mediterranean itself.
  • We never get solid confirmation of where Bill's ship went down, but Mrs. Valentino says she heard the Mens Scapus wrecked "a ways over to the southern coast, close to Africa." Mrs. Valentino lives on the northern coast of France, implying the "southern coast" refers to the southern coast of France. If Bill sank near Africa but off the southern coast of France, his ship would have sank closer to Tunisia or the Algiers. However, Bill's wreck is relatively close to a hydrothermal vent, which in the Mediterranean are exclusively found off the Aegean Archipelago and the western coast of Italy.
• Wholesome Crossdresser: Dipper dresses as a woman in Port L'Orient as a favor to Robbie, since Robbie wants him to sing with his band but Dipper is wary of humans discovering he's basically transgendered (although no one uses that terminology).
• Wooden Ships and Iron Men: Subverted. You definitely need to have a certain hardness about you to get through battles, but due to a combination of magic and Bill's completely historically unrealistic hygiene standards, life aboard the Mens Scapus is described as just about as comfortable as living on land, if not moreso due to a lack of all the untrustworthy people at port.