The Nephews, Webby, and Doofus attempt to earn a Junior Woodchuck badge in sailing while a sea monster is preying on Scrooge's shipping fleet.
This episode contains examples of the following tropes:
- Canon Foreigner: Black Pete appears in this episode, although he didn't in the comics.
- The Cavalry Arrives Late: Coast Guard Captain Tan arrives to arrest the pirates just after they get defeated without his help. Of course, given his characterization throughout the episode, this isn't too much of a surprise.
- Chekhov's Skill: Webby says that her only merit badge is for swimming. When Launchpad nearly drowns, she's able to swim out to him with a life preserver.
- A Father to His Men: Captain Mallard gets upset about how his first mate was apparently eaten by the sea serpent and also asks if the rest of the crew are alright after they abandon ship.
- Foreshadowing:
- Early in the episode, Webby notices that none of Launchpad's merit badges are for swimming. Later, she has to save him from drowning.
- First Mate Quackerbill's habit of saying "Arrr" provides some subtle foreshadowing about how he's a modern-day pirate.
- Good All Along: Dogface Pete is introduced unloading cargo from Scrooge's sunken ship (gloating about how it is legal salvage), has a suspicious conversation with Captain Mallard about a plan they have going on, and is modeled after a recurring Disney villain. However, Pete really is an honest businessman working with Mallard to hunt down the serpent that's been sinking ships. He's also horrified by Scrooge's apparent death and shows happiness when he turns up alive.
- Harpoon Gun: Dogface Pete fires at the sea serpent with a harpoon gun he found on a past salvage job.
- Hunter of Monsters: Captain Mallard, Dogface Pete, and two other sailors set out with a harpoon gun to pursue the sea serpent that destroyed Pete's salvage warehouse and Mallard's ship (eating Mallard's first mate, Quackerbill, in the process). Working with the heroes, they discover that the whole thing is a "Scooby-Doo" Hoax run by a Faking the Dead Quackerbill.
- Jerk with a Heart of Gold: Dogface Pete turns out to be this. His abrasive and proud personality makes him Scrooge’s main suspect for being the mastermind behind the sea serpent, but it is then revealed Dogface Pete is actually a moral and downright heroic sailor.
- Mechanical Monster: The sea monster turns out to be a crane/submarine combo covered by a costume.
- Our Hero Is Dead: The first act ends with Scrooge apparently being eaten by the sea monster. He turns out to be alive and well shortly before the end of the second act, being held hostage by the villains.
- Reasonable Authority Figure: Captain Mallard is essentially the leader of sailors and leads the investigation on the sea serpent. He also does his best to keep the peace; when Dogface Pete is hauling in some of Scrooge’s cargo, Mallard explains to an angry Scrooge how it is Pete’s property due to laws of the sea, then sternly scolds Dogface Pete for being rude to Scrooge.
- Red Herring: This episode's incarnation of Black Pete is a key suspect behind the phony sea monster, but he not only turns out to be innocent but is actually a hero!
- "Scooby-Doo" Hoax: The sea monster is actually a disguised crane attached to a submarine. The villains were using it so they could steal the cargo without suspicion, which worked until Scrooge showed up.
- Thousand-Yard Stare: Captain Mallard's second mate is seen staring ahead with a stunned, quivering expression after a sea monster apparently eats First Mate Quackerbill.
- Undying Loyalty: Most of the boys drop out of the tug of war between their boat and the sea serpent when they see Scrooge in the water. Launchpad soon realizes he's not going to win this one and orders Doofus to go over with the others. The young duck refuses to let him continue alone.
- What Happened to the Mouse?: Captain Mallard and Dogface Pete disappear after the submarine's sea serpent cover is torn off. The episode still has two or three minutes left, but they aren't shown reacting to Launchpad's near-death experience or the arrest of the pirates.
- Would Hurt a Child: The pirates operating the sea serpent submarine plot to sink the ship Scrooge's nephews and Webby are using to look for Scrooge and joke about it.
