If you?re not attracting adults, you may be missing out on an important and growing market.

When it comes to vacations, parents and children often have very different ideas about what?s fun. For kids, the fun of a waterpark resort is careening down a twisting water slide or splashing around in a play pool. But what?s in it for grown-ups?

?Wouldn?t it be nice if we all went on vacation and we all came back relaxed?? asks Treadwell Jones, aquatics manager at Larkin Aquatics in Kansas City, Mo.

As the waterpark resort market matures, a growing number of facility owners are beginning to wonder the same thing. So rather than just offering exhilarating rides and wet summer fun, more and more of them are playing up more European resort-like amenities with adult appeal.

While Americans will always gravitate to bright, happy, child-friendly surroundings, the phenomenon of an adult escape that?s less Disney and more Vegas is expected to be the wave of the future.

European standard

In Europe, where the waterpark resort has been in existence for more than 30 years, that kind of resort is already de rigueur. The popular Center Parcs resorts include tropical domes with waterparks, restaurants, grocery stores and child-care facilities. The facilities also offer horseback riding, tennis, archery, wall climbing, tanning beds and day spas.

?They started with the health concern being first and entered the indoor waterpark world from the fitness and health angle,? says Judith Leblein Josephs, operations analyst at Water Technology Inc., headquartered in Beaver Dam, Wis.

Europeans have long retreated to these destinations with or without the kids. In Sweden, one waterpark offers Friday nights for couples only, no children allowed. The park offers fine dining, clothing-optional swimming and massages on these nights, Josephs says.

Such daring offerings might never make it in the United States, but the idea of catering to adults could, especially for stressed-out parents looking for a break from kiddie fun.

?Europeans are more sensitive,? Jones says. ?In Europe, you come to relax, but in the States, there?s no quiet room.?

There?s also little in the way of services aimed at adults, says Jeff Coy, president of JLC Hospitality Consulting in Rochester, Minn. ?Our version is just so entertainment-oriented over here,? he says. ?But we?re going to hang onto that, and add things to become more service-oriented.?

Adult market

More adult-friendly resorts also offer another potentially lucrative advantage: attracting adults without children.

With their year-round appeal, indoor waterpark resorts are in the enviable position of being able to capitalize on this new market as well as the traditional family market. No wonder they are growing at a faster rate than the outdoor waterpark market, which is reaching its maturity, according to Coy.

But the market will have to adapt to maintain its momentum.

?The trick is how to keep someone in an aquatics facility for more than four hours,? says Jones. ?Once you?ve gone down the lazy river and watched your kids get exhausted, what?s next??

Offer a more subtle, sophisticated look, for starters, experts suggest. Like Las Vegas, waterpark theming is becoming increasingly popular, and increasingly adult.

Andrew Mowatt notes that this trend is moving America toward the European model. ?Developers are using the natural environment and making the overall planning, design and building more sophisticated than it?s ever been,? says the vice president of resort sales at Whitewater West Industries Ltd. in Richmond, British Columbia, Canada.

Grown-up results

Even individual rides are being affected, Josephs says. For example, today?s lazy rivers offer separate channels: a wilder one for adventure seekers and a quiet one for those looking for relaxation. Similarly, the rest of the waterpark resort can cater to different needs of different people those looking for a wilder adventure, and those wanting a quiet getaway.

Other changes are evident as well. Just as parks now come dressed in themes, they also come accessorized with games and amenities geared toward making parents happy.

A prime example is the addition of day spas to waterpark resorts. Here, women and men can spend a day being pampered from head to toe.

Places such as the Chula Vista Theme Resort in the Wisconsin Dells offers such adult havens. While the kids are playing in the waterpark, parents can enjoy a day at the spa. They can finish the relaxation in a warm hot tub while keeping an eye on their kids, either in family-style or an adult-only variety.

Fitness is another key grown-up amenity gaining the attention of more and more parks. At these resorts, adult guests can participate in yoga and aerobics, or work out in the fitness center with a personal trainer. Fitness buffs appreciate bodies of water that allow them to exercise against a current.

Golf, tennis and other sports also are offered at some of the full-service resorts that are expanding their recreation and entertainment, Coy says.

In the end, Americans will continue seeking the thrills of traditional waterparks, but they?ll also look for a balance between that excitement and relaxation entertainment. Waterpark resorts just need to figure out what that means for U.S. audiences, experts say.

?I?ve been saying we should try to fit this European model of service and comfort,? Josephs says. ?We will still have the fun and family atmosphere, but we will start to incorporate more services for the adults.?