The Rangers discover a sunken pirate ship and a huge cargo of gold, along with a crew of rats who have forgotten about the life above the surface.
Vexed with Dale's messiness, the rest of the Rescue Rangers order him to clean up all the litter. As a displeased Dale is throwing all the litter in the dustbin, he accidentally slips and falls into it. Unfortunately, the garbage man arrives at that precise moment to pick up the trash. The Rangers give chase to the garbage truck, but a little accident causes them to fall into the truck with Dale.
The Rangers end up in a large pile of garbage that is being towed out to sea by a barge. While they are still trying to figure out a way to return back home, a pirate barrel emerges from the sea right beside them. It fires a large net that catches a big pile of garbage along with Chip and Dale. The barrel and its haul disappear underwater, much to the horror of Gadget, Monterey Jack and Zipper.
The barrel tows the garbage, and Chip and Dale with it, to a sunken ship on the ocean floor. There the two chipmunks meet the Pi-Rats and their captain, Jolly Rogers. The Pi-Rats invite Chip and Dale to join them. Dale is all too eager to agree while Chip has his reservations. The Pi-Rats even allow Chip and Dale to join in their game of treasure hunt, after which they reveal their true intentions and lock the two Rescue Rangers in an old bird cage.
Above the surface of the ocean, Gadget manages to construct a submarine using bits and pieces from some of the floating garbage that fell from the barge. She, Monterey Jack and Zipper then pilot the sub to the sunken Pi-Rat ship to rescue their two teammates. En route they run into Billy the Squid who obliterates the sub. The three intrepid Rangers escape Billy's stalking tentacles and swim into the sunken ship.
The trio soon locate Chip and Dale and their captors. Monterey Jack dons a disguise and pretends to be the Pi-Rats' captain, Long Lost Lafitte. He then orders the Pi-Rats to release Chip and Dale and also instructs them to guard the treasure until he returns again. Everything was going according to plan until Young Ned, the real Lafitte's cabin boy brings a big wedge of cheese for his captain. Monterey Jack loses all control and rushes headlong towards the cheese, shedding his disguise and revealing his true identity to the Pi-Rats.
The Pi-Rats now tie up all the Rescue Rangers and make them walk the plank which is located right above Billy the Squid. The rangers, however, mount a daring escape and flee with the Pi-Rats in hot pursuit. Gadget then theorizes that if the treasure was unloaded from the ship, it would float back to the surface. While Monterey Jack and Zipper keep the Pi-Rats occupied, Gadget, Chip and Dale use a cannon to blast the treasure free from the ship and it floats upright to the surface.
The Pi-Rats are so happy to be able to sail above the sea as opposed to living under it that they end all hostilities with the Rescue Rangers. As the Pi-Rats set off to have real adventures, the Rescue Rangers board the barrel and start to make their way home, but not before Dale gives the Pi-Rats a 21-gun garbage salute.
- Corey Burton as Dale, Zipper, 'Arvey
- Peter Cullen as Monterey Jack, Young Ned
- Jim Cummings as Jolly Rogers
- Tress MacNeille as Chip, Gadget Hackwrench
- This episode was adapted as the first part of the "King of Beasts Caper" story arc in the Chip 'n Dale Rescue Rangers comic book by Disney Comics.
- This is the first appearance of Jolly Rogers and his Pi-Rats; they would appear again (slightly altered), in the episode "Chipwrecked Shipmunks".
- Long Lost Lafitte is named after Jean Lafitte, a famous 19th century French pirate.
- Several shots in this episode were used for the opening
- The shot of Chip, Gadget, Monterey Jack and Zip going over a park hill and through the fence on a skate
- The shot of Chip and Dale climbing to the top of mountains of garbage and looking around
- The shot of Chip kicking Dale into a parrot skeleton and the skull landing on Chip's head
- The shot of Jolly Rogers forcing Chip, Dale, Gadget and Monterey Jack to walk the plank
- The shot of Zipper looking startled
- The shot of Zipper slingshotting himself into several pirates
- The shot of the pirates firing at the Rescue Rangers
- The shot of Dale standing in front of a cannon and Chip pushing him out of the way