The River Wild

Victorian explorer David Livingstone reported the existence of the Victoria Falls back to the West after discovering them in 1855, and the numbers of tourists streaming to visit the "smoke that thunders" have been increasing ever since. Although some folks still prefer to take in the majesty of this geological wonder from the viewing platform, excitement addicts microlight overhead, whitewater raft below or bungee jump betwixt and between. Last summer, 75% of foreign visitors to the falls participated in adventure sports, according to Zambia's National Heritage Conservation Commission. For some of these thrill seekers, the falls aren't even the main attraction but a hazy, shimmering backdrop to the mighty Zambezi River and the challenges it presents.

Bundu Adventures, www.bunduadventures.co.za, and Zambezi Safari and Travel, www.zambezi.com, have added river boarding to the list of extreme sports on offer. Adrenaline junkies launch themselves 26 km down the Zambezi, through the winding basalt canyons of the Batoka Gorge, with no more than a wetsuit, helmet, lifejacket, fins and a body board with wrist leash. It's an irresistible challenge for river-boarding fanatics: a torrent of such force that it generates enough hydroelectricity to power both Zimbabwe and neighboring Zambia. Expert guides lead river boarders into violent Class IV and V rapids with dangerous drops and irregular currents and names like Stairway to Heaven and Oblivion; these waters are known to have flipped more inflatable rafts than any other rapids in the world. Then there's the wildlife: hippos' snouts break the surface of the water; baboon families clamber around at its edge and while only baby crocodiles survive the drop from the falls, they do grow up downstream.

American Richard Bangs, an international river explorer and award-winning author of Riding the Dragon's Back, about his first descent on China's Yangtze River, has led first river-boarding descents on 35 rivers worldwide. Bangs says that the rivers that cascade down such mountain ranges as the upward-thrusting Himalayas and Andes run rapidly continuously, leaving no room for human error. But the Zambezi gives boarders a chance to rest, "in that it has a beautifully designed sequence: a big rapid is almost always followed by a calm pool."

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Marc Goddard, former world rafting champion and owner of Bio Bio Expeditions in California, www.bbxrafting.com, has rafted on the Zambezi every year since 1989. He says that, due to the river's special hydrotopographical features, "if you use your fins to face upstream at the right moment on a standing wave, you can stay there forever." Just save plenty of energy for the 250-m vertical climbs out of the gorge on handmade bamboo ladders that punctuate the rock face along the way.

Bangs remembers the pioneering days of the late '70s when he struggled to convince expatriates and local hoteliers that the Zambezi was navigable: "It is hard to believe that the Zambezi has now become an adventure-sports Mecca." Livingstone might be surprised at the river's new activities, but no doubt he'd wholly approve of the spirit of adventure that informs them.