The gang visits a marine theme park, which practically resembles Sea World on the cheap -- your run-of-the-mill stage show, an exhibit of the world's greatest maritime disasters, a souvenir stand with tired employees hawking bubble guns, and a trained shark show -- using mechanical sharks. The Rugrats, as usual, run away to the park's centrepiece -- a ship that houses the park's aquarium. This, of course, leads the Rugrats to believe that the ship is sinking, so they find ways to float the already dry-docked boat.