One of the best elements of the Finding Nemo Submarine Voyage isn't seen or heard by its riders at all. Three Seagulls from the film, perched on a bouy, cry, "Mine! Mine!" every time a submarine passes by.
The birds, many yards from shore, are not immediately obvious to most guests walking by the lagoon. Fans of the film, however, immediately catch the familiar call drifting faintly on the breeze, and stop to investigate.