The idea for a Little Mermaid dark ride has been in the so-called blue-sky stages of creative brainstorming at Walt Disney Imagineering since the movie premiered in 1989 -- from rough artist sketches to scale-model mock-ups to fully realized concepts.
After 22 years in the making, Little Mermaid: Ariel's Undersea Adventure will officially open Friday at Disney California Adventure.
"The attraction has been worked on quite a bit since the film came out," said Lisa Girolami, Imagineering's senior show producer for the new ride. "We just needed to wait until the technology was able to catch up and really deliver the ride we wanted."
Photos: Concept art for the Little Mermaid dark ride
Over the years, the ride went through several iterations, including a version shown in the 2006 DVD release of the movie that featured an overhead ride system similar to Peter Pan's Flight atDisneyland. (Ultimately, Imagineering went with a Haunted Mansion "Doom Buggy"-style ride vehicle.)
At each stage of development, Imagineers cut songs ("Les Poissons"), characters (Ariel's mermaid sisters) and story lines (the father-daughter relationship of Triton and Ariel) to focus the 5 1/2-minute ride on Ariel's journey.
"In the end, seven of the 11 scenes were restaged, including the last two scenes, which were changed the most," said Larry Nikolai, Imagineering's show designer and creative director for the ride. "The last scene we added was Ursula's defeat."
Related: Scene-by-scene preview of the Little Mermaid dark ride
From the very beginning, Imagineers knew the movie's Oscar-winning soundtrack would play a central role in the ride.
"What we did was stay true to the songs in the film because we knew those would immediately resonate with the guests," said John Dennis, who served as music director for the ride. "The orchestral score is inspired by the film using the same musical vernacular. Those themes still bring goose bumps when I hear them played."
The challenge was relying on the music to tell the familiar story, with Scuttle the seagull providing only a brief prologue and epilogue.
"We had to distill each song down to the moment that delivered best on storytelling," said Dennis, who often had to snip musical loops down to 20 seconds. "A lot of times we had just enough time to deliver a verse and the chorus."
Where the music forced Imagineers to compress time, the ride's audio-animatronics presented a similar challenge in the form of limited space. To make Ariel's fingers and hands move, technicians had to run animatronic wiring through her waif-like wrist.
"She's probably the most complicated audio-animatronic character we've ever done," said Girolami, who started with Imagineering in the mid-1980s. "She's this tiny little thing. You don't have a lot of room with her."
At 9 inches tall with a head the size of a golf ball, Sebastian the singing crab proved even more daunting. Imagineers installed tiny rear-projection systems in his eyes to make the animatronic character seem more lifelike.
"The eyes are the most important thing on a character. That's what people are always drawn to," said Nikolai, who worked on Splash Mountain atDisneyland and the Monsters Inc. dark ride at California Adventure. "His eyes can do anything we want him to do. They can blink, change expression and look all around."
But the restrictions of time and space are what drive Imagineers, Disney's creative arm. Even if it takes 22 years.
"We never say never," said Girolami, who has worked in the movie industry and as a novelist. "That's what's exciting about working at Imagineering. We're always saying, 'That's never been done before, but we're going to do it.'"
An identical version of the ride, called Under the Sea: Journey of the Little Mermaid, is expected to open in 2013 at the Magic Kingdom in Florida.