What is zorbing?

For Dwayne van der Sluis and Andrew Akers, the idea of walking on water held endless fascination. That's why the two friends set out to develop a floating ball that could hold a standing person on water. At the time, such balls were already in production, but they had to be inflated and deflated as the passenger entered and exited, which took time and effort. Van der Sluis and Akers thought they knew how to solve the problem -- design a ball within a ball.­

The idea for the double ball was that the air would remain pocketed between the inner and outer balls, and the rider would climb inside the inner one. This way, the ball stayed inflated at all times. Van der Sluis and Akers built a prototype, which they patented and trademarked as the zorb.

As the partners hoped, the ball enabled passengers to walk on water. But there were other pitfalls. On the open water, in the lightweight ball, the person had little control over the ball's movement or direction.

So, what to do with the plastic sphere? Well, strap someone inside of it and then roll it down a hill, of course. Since New Zealand was known around the world for offbeat extreme sports developments, such as bungee jumping, the zorb might attract a following, the zorb inventors thought.

Akers and van der Sluis picked up two additional partners, and a business was born. The men insisted on proper training and maintenance to guarantee safety and integrity. For this reason, they chose to franchise zorb operators rather than sell the zorbs outright.

In 2000, van der Sluis made the decision to return to his original career as a software engineer, and left the company. Six years later, Akers, citing differences with one of the other partners, left the company as well. Despite these business distractions, the company has continued to add franchises.

In the U.S., you can go zorbing in the Smoky Mountains of Tennessee. You can also go zorbing in the Czech Republic, Los Cabos, Slovenia, Ireland, Sweden, Thailand, Korea, Australia's Gold Coast, and the spot where it was developed, Rotorua, New Zealand.

Prices vary for different packages, but generally the thrilling ride is about $40 a trip. The price is comparable to spending the day at a local amusement park or taking a helicopter tour.

Although zorbing always takes place on land, there are two types of zorbing rides: dry and wet. In areas where there are no natural hills or contours for the zorb to maneuver, the operator builds a metal track.

On a dry ride, the rider is strapped into the zorb against one wall. The operator releases the zorb, and the rider rolls, head over heels, downhill. In hydro-zorbing, the passenger isn't strapped to the zorb wall. The operator adds about five gallons of warm or cold water -- depending on the weather -- to the inside of the zorb, then sends the passenger on a wild ride. The passenger slips and sloshes around the inside of the ball as it rolls.

Even though the zorb is clear plastic, the passenger is somewhat limited in what he or she can see while rolling downhill. Because the zorb has two layers of plastic and because of its speed, it becomes difficult to discern the sky from the ground when you're on a roll.

The sphere doesn't travel fast enough to become airborne over bumps, but it will bounce along as it turns down the hill. The actual speed depends on a variety of factors, including whether you're rolling into a headwind, the weight of the passengers and if you're strapped in or riding free. When strapped in, you'll pick up more speed. The wet ride experience is compared to being a pair of socks in a washing machine.

Contrary to what you might think, zorbing isn't particularly nauseating -- well, at least according to Andrew Akers, one of the sphere's inventors. He says that in over 100,000 rides, no one has ever thrown up. While the zorb moves downhill at a good clip, because of its circumference, the person inside only makes one complete rotation about every 30 feet (9 m). While the length of each track varies, you can generally expect about 700 feet (213 m) of fun on your ride.

Before you commit to hurling yourself face first downhill, you may want to consider the safety of zorbing. There's a lengthy waiver and release form to sign before you hop in the orb. But all-in-all, zorbing is safe. A harness keeps the rider in place on dry rides, and the 459 cubic feet (13 cubic meters) of air sandwiched between the two plastic balls provides ample cushion.

A trained operator also helps to ensure the passenger's safety. Because the zorb is on a confined track, the rider has no control over steering or stopping the ball. The operator at the top releases the ball. At the bottom of the hill, the zorb gradually slows to a stop, where an operator is waiting to secure it while you disembark. A zorb course on land has small berms that keep the zorb in line. Zorb tracks have barriers on each side to prevent the zorb from tipping off the edges.

You may be wondering, "What happens if it pops?" While it's not unheard of for a zorb to spring a leak, it won't pop and torpedo down the hill like a balloon releasing air. Any hole in the zorb will lead to a slow air leak. As the air leaks out, the zorb loses its round shape and rolls slower and slower until it settles to a stop. Of course, with the amount of air a zorb contains, it can lose a good bit before the passenger notices any change in performance at all.