While fishing with his girl, Willie tangles with denizens of the deep, including a vast and menacing Poseidon figure and a drunken pirate (Davy Jones), who swills hooch while slamming his peg-leg stump on the deck of his room.
Willie unintentionally hooks King Neptune.
The King of the Sea becomes angry, and adventures on and below the waves ensue.
Lots of sea-creature sight gags, too.