SeaWorld Orlando's Clyde & Seamore show closes for revamp.

Lee and Donna Jenkot never tire of SeaWorld's "Clyde and Seamore Take Pirate Island."

The Orlando retirees have watched the sea lions' antics at least 50 times since the nautical-themed show debuted 15 years ago. The goofy gags are always the same, but because the show involves unpredictable animals, Lee Jenkot said, "you never know what's going to happen."

The "Pirate Island" tradition will end next weekend, when SeaWorld's longest-running show comes to a close. A sea-lion show with a new theme will open next year.

As it rewrites the script, SeaWorld faces a common challenge for theme parks: keeping loyal fans happy while making sure attractions don't go stale.

Many visitors develop tremendous loyalty to shows, rides and other theme-park features. Even minor tweaks can set off major complaints. Consumers get especially attached to park attractions because they can't be experienced at home such as a movie or a ball game, said Robert Niles, publisher of ThemeParkInsider.com.

Websites devoted to attractions also fuel fans' interest in their details, Niles noted.

All this loyalty can create a dilemma for the parks, however, because they need to keep appealing to younger visitors.

"If it becomes a classic, you're almost committed in some form to hold on to it. You could update it, but … if you reboot it, you take the chance of upsetting some of the fans that wanted at least the core appeal of the original," said John Gerner, founder of Leisure Business Advisors in Richmond, Va.

SeaWorld Entertainment's director of creative development, Brian Morrow, said executives decided to change Clyde and Seamore's routine because their set needed refurbishment anyway. The theater will be closed while a new set is constructed.

The company has given just a few details about what will replace the 20-minute production. Sea lions Clyde and Seamore will still have starring roles, the act will still rely on jokes, and the show's mischievous otter will stay. But there's no word yet on the future of the pre-show mime, who has made audiences chuckle for decades.

Figuring out the right combination of old and new for theme parks isn't always easy, and some makeovers have been more successful than others.

Take Journey Into Imagination at Walt Disney World's Epcot. The ride closed in 1998, 15 years after its debut, and reopened the following year with the role of Figment the dragon dramatically reduced. Visitors hated the change, and two years later, Imagination shut down for yet another overhaul.

Many don't like the newest version, either. For one thing, they miss a bearded character named Dreamfinder, Niles said.

"Imagineers ... imagine something else for this space, okay?" one review on Yelp suggests.

Disney said it did not have any executives available to discuss the makeover of attractions, and Universal Orlando declined an interview as well.

Niles said Disney had more luck with adding Johnny Depp's Jack Sparrow character to Pirates of the Caribbean. That broadened the ride's appeal, he said, "without turning off any more than the most curmudgeonly old fans." Visitors also generally liked changes to the Haunted Mansion, Niles said. Those included improvements to the hitchhiking ghosts and the addition of a scene with M.C. Escher-style staircases running in various directions.

It's not just rides and shows that earn guests' loyalty. Disney is now refurbishing the Polynesian Resort, one of its original hotels. One upset fan started a petition on change.org to keep the lobby waterfall that Disney announced it would remove, and about 2,500 people have signed it.

Universal, which is almost 20 years younger than Walt Disney World, has made some adjustments, such as a makeover of a Beetlejuice musical show that has received mixed reviews.

But in general, when Universal decides it's time for a change, "they tend to wipe it out rather than do anything incremental with it," Niles said. "They're not about nostalgia the way Disney is."

At SeaWorld, executives say they expect a busy week as fans with fond memories of the Clyde and Seamore pirate show try to catch it one last time.

Still, some visitors said it might be time for some tweaking. They include Joanne Gallagher, a British tourist who saw the show this week with her 10-year-old daughter, Lucy Cook. Both mother and daughter loved the sea lions themselves. They didn't care as much for the script, which includes gags such as a trainer holding up a fish and exclaiming, "Holy mackerel!"

"It's not the best show I've seen," Gallagher said.

spedicini@tribune.com or 407-420-5240