Deep in the heart of landlocked Texas Hill Country, I ride a major wave. For about 30 seconds, before wiping out and being whipsawed head over heels into a churning maelstrom, I briefly understand the glorious rush of surfing.

I also, at the insistence of my 11-year-old, confront my fear of heights and plunge headfirst down a three-story chute at Schlitterbahn Waterpark Resort. That gives me the courage to allow myself to be shot out of the Master Blaster by water jets that catapult our rubber raft six stories into the air, then drop us like a sack of cement flowing off the edge of Niagara Falls.

Ten years ago the best water parks offered little more than a few twisty slides and a faux log sliding down a chute. But four major companies and a dozen or more smaller ones have been on an innovation binge in the past decade.

The parks have all kept the little slides and sprinklers and pools that occupy the toddlers, the grandmas and the generally timid. But across the country, they're increasingly adding attractions on testosterone. Water rides that are roller coasters in disguise. Machines that create waves out of water blasting from pipes at the rate of up to 100,000 gallons a minute. Rides that suck you down dark serpentine tubes and shoot you through white-water rapids.

We've chosen to test the water at Schlitterbahn in New Braunfels, Tex. Sitting nearly smack in the middle between San Antonio and Austin, and less than an hour's drive from either city, Schlitterbahn is arguably the world's largest water park, and is nearly universally considered the best.

More than 40 rides and attractions are spread over 65 acres in two sections of park connected by a tram. A river runs through it, and clumps of shade trees offer relief from the heat. Between rides, you can cool off by standing under showers of water that drop in gentle sprinkles or beat down your back in great pulsating bursts.

The biggest surprise for me is the hill country surrounding the park. My previous Texas experience had been confined to Dallas and Houston, and I didn't get why Texans took such pride in their state. The hill country, with its flowing rivers and historic towns, made me understand.

German immigrants settled New Braunfels and the neighboring town of Gruene in the 1800s. Much of what they built remains, including homes of old German fechwerk -- half timber, half masonry. The small-town charm is heightened by the sight of people carrying black inner tubes around the streets.

The spring-fed Comal River meanders through New Braunfels, and lazing on the river on a summer's day is a major pastime. Those with an adventurous streak that hasn't been fully satiated at the water park head to Gruene, where the rushing Guadalupe River provides white-water adventure.

In the early 1970s, Bob and Billye Henry (Billye was the wife) purchased a small hotel on the Comal River in New Braunfels. In 1979, they built a 60-foot structure intended to look like the Solms Castle in Braunfels, Germany -- home of the original settlers. They attached to the sides of their faux castle four slides, pumped in water from the river and called their family-made creation Schlitterbahn ("slippery road" in German).

Thus was created the world's fourth water park, a concept quickly copied throughout North America.

Today, associations count more than 1,000 water parks in North America. But even when traveling abroad, you're likely to be near one of the 600 or so water parks overseas. They're currently the rage in Eastern Europe and Asia, says Rick Root, president of the World Waterpark Association, and in the past decade, growth overseas has outpaced even the fast development in the States.

Root says it's hard to define a water park -- a simple little slide or two just doesn't cut it anymore. However, size is a major indicator of what you'll find at a given park. He says most indoor water parks are about 50,000 square feet, with outdoor parks starting at about 10 acres. And then you've got the behemoths -- the closest giant to Washington is Water Country USA, which is spread over 43 acres of Williamsburg.

"For many years, a serpentine tube or slide was the ultimate water park experience," says Root. "But over the last 10 years, we've seen a tremendous amount of innovation by suppliers coming up with new rides. And there's no end in sight -- they keep coming up with more."

Schlitterbahn has most of what's out there, and it turns out that a day and a half isn't quite enough time to try it all.

We arrive in the late afternoon and head directly to the room we've booked within the park. We're delighted to find that the motel -- Schlitterbahn also rents condos and houses -- is a simple one-story building with a deck overlooking the Comal. The motel provides free inner tubes in case you want to spend some time away from the park, simply free-floating.

It feels like a rustic hideaway, yet we're just yards from the entrance to the rides. With only four hours to spare before the park's 8 p.m. closing, we rush to line up for a boogie board and head up a stairway to the FlowRider.

This faux surfing experience was invented by a California company called Wave Loch a few years ago. About a dozen or so have been installed around the United States -- the closest to D.C. is at Paramount's Kings Island near Cincinnati -- but it's proved particularly popular overseas. Surfers are riding inland waves in Korea, Japan, China, Saipan, South Africa, Russia, Italy, Ireland, the Netherlands and even Jedda, Saudi Arabia. (For a list of locations, go to

You enter the Schlitterbahn FlowRider by slipping head first on a boogie board down a short chute, where you are quickly confronted with a thin, fast-moving layer of water that builds behind you into a wave. You ride -- either lying flat or on your knees -- until you crash. You know your turn is over when the wave throws you into a rushing pool of water that shoots you down a wide chute.

Only one person at a time can ride the FlowRider, but most of us are amateurs, so the line moves quickly. Every now and then, though, a FlowRider expert has a turn, and that can take a while. We all watch in awe, for example, as a preteen does tricks on his boogie board, gliding up the crest of a wave then jerking his board around 180 degrees to catch a second wave, and sometimes a third and fourth and fifth before wiping out.

My first two tries I'm taking great draughts of water up my nose before I've even had a chance to register that I've been somersaulted off the wave. By my third try, I'm getting the hang of it and wishing I could afford to install a FlowRider in my back yard.

But my daughter has spotted the six-story tower that is the starting point for the Wolfpack Family Raft Ride, the Black Knight Tunnel Ride and the Master Blaster Uphill Water Coaster. The Master Blaster has been voted best water ride in the United States five years in a row. It has the longest lines in the park -- on our weekday evening, the wait was about 20 minutes. (Amusement Business, an industry publication, estimates that the park gets close to a million visitors a year during its late-April to mid-September season.)

It's hard to argue that you're too scared to try when you're in line with kids just out of diapers. So we settle into a raft for two for the Master Blaster. First you fall six stories. Then jets of pulsating water push you back up a roller coaster-like path, only to drop you again in a series of thrills that last for more than 1,000 feet. I imagine it's a lot like being shot out of a water cannon at the circus, only it takes a lot longer. My favorite ride is the Torrent Wave River -- a long circular stretch of water rocked by waves of various sizes. You can ride the waves in a tube or simply be carried around bareback. It's something like playing in the ocean, only the "ocean" in this case endlessly continues circling, instead of washing into shore.

Four hours of climbing stairs and being pummeled with thousands of gallons of water leaves us ravenous, but we take the time to drive three miles to the town of Gruene, along the fast-flowing Guadalupe.

The entire town, settled in 1845, is on the National Register of Historic Places, and a gorgeous Victorian mansion here has been turned into a B&B. There are antiques and handicraft stores, a wine shop with Texas wines to taste and buy, and a General Store that hasn't changed anything but the merchandise in more than 150 years.

A band is playing in the oldest dance hall in Texas, and kids join parents and grandparents for square dancing. Next door, we eat along the river in an old cotton gin, aptly named the Grist Mill.

Two river outfitters are based in Gruene, and we're sorry we didn't allow more time to explore the town and raft a bit of real white water.

We have just one full day for Schlitterbahn, though, and are waiting in line when the doors open at 9:30 a.m. (Even though the park doesn't officially open until 10 a.m., workers come early and let you start riding immediately.) We spend the next eight hours wet. One unique feature at Schlitterbahn is that the park incorporates the river and its spring-fed water into the rides. Since the water doesn't need to be chlorinated, old-fashioned black tire tubes can be used, lending a yesteryear feel to some of the attractions.

We each pick a tire from a huge pile for what is billed as the "world's longest tube chute." This 45-minute ride carries you through about half the park and feeds you into a lazy river or a fast-moving tunnel, depending on which path you choose to take at a fork. The water of the Comal is a constant 70 degrees, so it provides a satisfyingly chilly reprieve from the beating Texas sun.

It turns out that there are dozens of ways to throw people down hillsides and towers. You can make them twist and careen through enclosed spaces and open spaces. You can have them lie down on their backs and race through a luge-like course feet-first. You can place them on thin strips of plastic and send them head first into a shallow or deep pool. You can isolate them in their own little tubes or speed them around in rubber rafts that hold a family.

We plan on staying at the park the full 10 hours it's open. But after eight hours, we're exhausted. We figure we'll rest an hour, hurry back for an hour's worth of thrills, then finish off the day by gently tubing the Comal until dark.

We head to downtown New Braunfels, where we find that our room at the Prince Solms Inn, a Texas heritage landmark, has a big, comfy wrought-iron bed. We won't make it out of the room that night, and we never see the park again -- at least not this trip.

Neither I nor my younger companion will be able to do a full 10 hours, I think, until they create yet one more innovation: waterproof escalators to replace the stairs to the tops of thrill rides.

Ride the waves at Schlitterbahn, one of the world's biggest water parks.