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.
- 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.
- 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.
- 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.
- 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.