Phat!

In a concrete cavern below the Royal Festival Hall on London's South Bank, a group of skateboarders are practising their manoeuvres while, a few feet away, passers-by idle at secondhand bookstalls or take in the view of the Thames on this bright, cool summer's afternoon. Not everyone is oblivious to them, though. A shifting audience stops and gazes down into the gloom, its attention drawn by the clatter of the boards and the crisscross patterns of silhouetted figures on the move.

One by one they come towards us, traversing an expanse of floor that affords them a run-up of about 30 yards to the point where the skateboarder's art comes together in all its gravity-defying beauty. This is a perimeter wall, sloped at an angle of about 45 degrees, measuring no more than 10 feet from bottom to top. It doesn't sound like much space to work in, but get your speed right ­ not too fast, not too slow ­ and you have take-off.

These skateboarders are dedicated guys. And the spins and leaps, when they succeed, are impressive. But there are many more misses than hits, and when I heard one onlooker mutter, "Not very good, are they?" I was inclined to agree. Then I was put right by a man called Alan Glass, who was hovering on the edge of proceedings, making a video of the action for a skateboarding company.

"Not everybody pulls their tricks the first time," he explained. "You might need an awful lot of attempts. Even with the guys you see on MTV doing incredible jumps, you have to remember all the misses that have been edited out."

Skateboarding's toughest challenges are very tough indeed. And in every ride and jump there's a quest for an ideal that right now ­ with the activity enjoying one of its periodic booms ­ can be seen to represent something much bigger and wider: nothing less than the struggle for the soul of skateboarding itself.

Skateboarding's roots in the UK, legend has it, lie in the long hot summer of 1976, when it was a kid's toy, nothing more and nothing less. It's been in and out of fashion ever since, but there are two aspects ­ apparently contradictory ­ of the latest craze for it that make it different: one is the degree to which skateboarding has become politicised, allying itself with the forces of urban protest and a youth culture that has tried to retain its spontaneity and integrity in the face of growing commercial interest; the other is the way it has been taken up by a new generation who have been sold an image of street credibility through music videos and computer games. In Britain there are an estimated 300,000 skaters supporting a £10m economy. In America it's vastly bigger still.

At 24, with more than half a lifetime of skateboarding behind him, Alan Glass bemoans the way it has become cool again. "For me and my friends, the best times were when it wasn't fashionable. No embarrassing adverts on TV, no godawful boy bands posing with boards on the cover of Smash Hits, no nothing. Just me and my friends skateboarding while you lot were at work, blissfully unaware that you'd ever have to read about such a futile pastime ever again."

Thus speaks a true aficionado who finds a bunch of johnny-come-latelys muscling in on the scene. And to give you an idea of Alan's credentials, he broke his leg skateboarding in a Safeways car park a couple of years ago. "How uncool is that?"

Among the skateboarders Alan was filming was a 29-year-old Ulsterman called Niall Neeson, who has earned a partial living out of skateboarding, as a writer and photographer, for most of the 13 years he has been at it. "For me, coming from a backwoods society, it was something to get into that wasn't glue-sniffing or paramilitary activity," he said. "It's about a connection with innocence ­ a very bohemian thing, centred around travel." He mentioned Jack Kerouac, and the importance to the skateboarding ethic of "reinterpreting architecture" ­ like the South Bank complex ­ that certainly wasn't conceived with skateboarders in mind.

To find skateboarding in a more controlled ­ some might say sanitised ­ environment, you need to go to one of the purpose-built skateparks that have sprung up around the country, like the hugely successful PlayStation centre underneath London's Westway. There, the layout has been created by design not accident, younger kids (and their parents) feel safer, and a corporate giant ­ in this case, Sony ­ can get in on the act by putting up money for the facility. This is one future for skateboarding, along with events such as the British leg of the skateboarding World Cup (see "The facts") and will double as an enormous trade show for skateboarding gear.

Co-organiser Vikas Malik defended the event against charges of exploitation by business. "In the past, brands have thrown money at skateboarding in order to be associated with something cool. Now there are people like myself who are wise enough to know that's not the way forward. We're going to be showcasing skateboarding for the widest audience, without compromising its ideals."

With a raft of sponsors, and top skaters from Britain and Europe taking part, Malik's Freewheelin' organisation are able to put up £25,000 in prize money, which he says will help good skaters become even better. Danny Wainwright, one of Britain's best, is gaining financially to the extent of enjoying sponsorship, says Malik, "but it's not as if he's advertising hair shampoo." Malik accepts that skateboarding ­ "once a little bit existentialist, a little bit loner" ­ has become more middle-class, and he sounds happy about that. "We're giving families a show that's not just shabby and thrown together."

As the author of The Concrete Wave, skateboarding's foremost historian is a Canadian called Michael Brooke. He sees beyond the sport's ups and downs to something he thinks will endure. "It's the old adage about youth culture: if it's in it's out, and if it's out it's in," he says. "As soon as corporate America latches on to something, the game's up. There was a talk of skateboarding going into the Olympics. That's the last thing skateboarders want."

Resistance to the forces that would market £100 skateboarding shoes all over the globe has been in healthy evidence. Nike's attempts to enter the skateboarding market were made to feel unwelcome. Some specialist brands have refused to sell to the big chains. "At the core of skateboarding there's a group of people who will withstand everything that's thrown at the sport," says Brooke.

Alan Glass is certainly one of those, but even he admits that there are contradictions. "I've got friends who have been signed up by advertisers, flown to America for a shoot and handed thousands of pounds, and I suppose good luck to them."

Plus, as a side attraction to the Docklands event, there will be a mini-festival of 15 specially commissioned skateboard videos, with a prize for the winner. And one of them, Alan Glass tells me, is being shot by him.

Additional reporting: William Fairman and Tom Davies