[[quoteright:150:http://static.tvtropes.org/pmwiki/pub/images/Riptide-book-alt-cover_8797.JPG]]
[[caption-width-right:150:Watch your step]]
''Riptide'' is an 1998 adventure novel by [[Literature/AgentPendergast Douglas Preston and Lincoln Child]] inspired by the real-life Oak Island Money Pit; a possible buried treasure horde off the coast of Nova Scotia that has resisted two hundred years of excavation attempts through lethally dangerous floods and cave-ins.

Set off the coast of Stormhaven, Maine and targeting the fictional Ragged Island Water Pit, the novel focuses on Dr. Malin Hatch, whose family has owned the seemingly worthless island for several generations after his grandfather became the latest in a centuries-long line of treasure hunters to bankrupt themselves attempting, and failing, to recover its now-legendary horde.

The novel begins in 1971 when a seven-year-old Hatch is traumatized by an unsupervised trip he and his twelve-year-old brother Johnny take to the island while their parents are away, involving a venture into a freshly exposed secret tunnel and the horrors it leads to. The rest of the book takes place twenty-five years later as the adult Hatch is approached by the weathered "recovery specialist"(professional treasure hunter) Captain Neidelman. With a fleet of ships, cutting-edge technology and twenty million dollars in capital, the captain is invested in recovering the 400-year-old treasure once and for all. Nearly half the profit will be Hatch's.... if he can face the nightmares of his childhood long enough to claim it.

There is more to worry about than tragic memories however, as the expedition unfolds and they discover the dark secrets of the Water Pit's designer(an Renaissance architect with a penchant for genius codes, imprisoned by the gruesome pirate who stole the treasure horde in the first place) and encounter disturbing historical references to "St. Michael's Sword", a mysterious artifact cursed with the power to "kill anyone who looks at it"....

Not to be confused with the 1960s Australian TV series or the 1980s [[Creator/StephenJCannell American TV series]].

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!!This novel provides examples of:

* AMinorKidroduction: The story starts with Dr. Hatch as a boy exploring the island with his brother.
* ArtifactOfDeath: St. Michael's Sword. [[spoiler: A sword forged from a meteor that's so radioactive it can kill everyone within a few square miles if taken out of its lead casket]].
* BadVibrations
* BigEater: Kerry seems to live on ice cream sandwiches.
* BoobyTrap: Oh boy....
* BreakTheBadass: [[spoiler: Happens to Hatch during the entire climax; implied to have happened to Neidelman in the past.]]
* ChekhovsGun: [[spoiler: the Geiger counter.]]
* ChekhovsGunman: [[spoiler: Reverend Clay is just a nuisance of a bible thumper until he gets stranded on the island so he can save Hatch and Bonterre.]]
* CollapsingLair: [[spoiler: Macallan designed the Pit to collapse in on itself and down into the depths of the piercement dome.]]
* CuriosityKilledTheCast
* {{Curse}}: The treasure is rumored to carry a horrible curse on it that claims the lives of those who try to retrieve it.
* DeathTrap: All over the Pit's design.
* DoorOfDoom: Hatch's brother died when he set off a booby trap in a secret tunnel under the Water Pit.
* DungeonBypass: Attempted highly unsuccessfully by previous would-be excavators of the Water Pit.
* DurableDeathtrap: Justified.
* FireAndBrimstoneHell: What Clay preaches is waiting for those who lust for the treasure.
* HeroicSacrifice: [[spoiler: Reverend Clay exposes himself to a lethal dose of radiation to save Hatch and Bonterre from the same fate.]]
* HeroicSafeMode: Hatch has little memory of escaping from the shore tunnel as a seven-year-old.
* {{Mangst}}: Hatch throughout the whole book, [[spoiler: secretly Neidelman, as Hatch learns]].
* MatchlightDangerRevelation
* MeaningfulEcho: "''Ye who luste after the key to the Treasure Pitt shall find instead the key to the next world, and your carcase shall rot close to the Hell where your soule hat gone.''" [[spoiler: Bonterre repeats these lines from the journal (which had seemed like a moral warning when first deciphered) after the treasure and the island collapse into the depths of the piercement dome.]]
* NeverFoundTheBody: Johnny Hatch, among others who were claimed by the Water Pit. [[spoiler: Not finding his body drove his father nearly mad until he died on the island still searching for his boy.]]
* PirateBooty: The largest horde of it in history, so they say.
* PitTrap: Unintentional ones all over the island.
* SacrificialLamb: [[spoiler: Kerry Wopner]].
* SciFiWritersHaveNoSenseOfScale: An odd example: [[spoiler: When they finally penetrate the treasure chamber, it's described as an iron room "about ten feet square". Nevermind that Ockham's treasure is described as having rendered his fleet of ships sluggish earlier in the novel and containing(among many other things) ninety million gold talents stolen from Spain, but the vast and elaborate contents of the chamber itself are listed in the same paragraph, and they sound like far more than would fit in the average person's living room. It's almost like it was meant to be meters or yards square, at the least]].
* ThisWayToCertainDeath: "''First will ye lie; Cursed shall ye cry; Worst must ye die''"
* [[spoiler: ThunderboltIron]]: [[spoiler: St. Michael's Sword was forged from iridium from a meteorite.]]
* UndeadAuthor: Averted. Red Ned Ockham's entire crew mysteriously died or disappeared and it's up to the main characters to figure out what happened on their own.
* VeryLooselyBasedOnATrueStory: Based on the Oak Island Money Pit. The real one still has never been successfully excavated.
* ZillionDollarBill: The treasure itself is estimated at over $2 billion
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