Welcome to Queenstown, New Zealand, the white knuckle capital of the world and the home of river surfing. As the latest extreme sport to cause many a hardened adrenalin addict to beg for mercy, river surfing is top of the thrill list. Here, the only team in the world with the guts (and perhaps the questionable mental condition) offers river surfing to those who appreciate the "pioneering spirit" of the Kiwis. However, it is not strictly surfing: technically it is body boarding, where the upper half of the body rests on a mini surfboard known as a boogie board, leaving the legs free to kick like crazy. The result? The best day's white water rafting you've ever had - without the raft.
The kit consists of a boogie board (just a jumbo polystyrene float), attached to the wrist by a long piece of cord and fastened with Velcro. This means that if and when we part, it will hopefully not be for too long. The board is accompanied by uniform helmet, wetsuit, fins, lifejacket and a raging river that spews wild white water for four long kilometres.
While the group kits up, Tony, the guide, gives careful instructions, coming out with such gems as, "If you get sucked under, don't panic, just hold your breath until the river chucks you out".
Surfing a fairly calm stretch of river, we practise the skills we will need: manoeuvring the board in the current, controlling speed, and positioning ourselves for both rapids and calmer water.
Usually the surfing takes place near the bungee jumping bridge on the Kawarau River, on the outskirts of Queenstown. However, huge storms have flooded both the river and the town, and the usual raging rapids look as peaceful as garden ponds. So today, as fate would have it, we are going to Roaring Meg's, a stretch of water usually avoided by "inexperienced commercial surfers" such as ourselves.
As with white water rafting, the rapids are graded on a scale of one to six, where one is easily passable and six is out-of-bounds. "I'd rather put my arm through a mincing machine" type zone. Tony tells us that we have just practised on a grade one rapid. Roaring Meg's is rated as a grade four.
Arriving at the power station, our departure point for this journey, we clamber out of the van, excitement running high. Peering over the rocks, our confidence soon turns to silent trepidation as we take in the sight below. It is not a river as we know it; no peaceful punting or supine swimming here. Thousands of litres of turbulent water angrily crash against the rocks in a frenzy of froth and foam. Small pockets of water whirl into eddies and larger areas give way to the energy of speeding whirlpools, all whisked downriver into oblivion, caught up in the fierce current. We nervously feast our eyes on the smorgasbord of danger zones which await us.
One of the party comes to his senses and decides to get back in the van. The rest of us continue, and although somewhat daunted by the ferocity of the river, this is what we're here for; after all, we wanted a new adventure; a dangerous thrill.
Tony is guiding me and four others, and gives a last minute briefing before clambering over the rocks to the entry point. He stresses the importance of keeping together in the water so that he can help if necessary, and this means leaping off a five metre high rock into the deep unknown in unison.
One deep breath and I'm in. My inner calm and general feeling of control get swept away with the rapid I am now immersed in. Gulping for air, there is no time to be terrified as, for the second time, I get dragged underwater. This is how it must feel to get trapped in an avalanche; just when you think the danger has passed, you are swept up again by a natural force so powerful it renders you incapable of self-defence.
Above my head, the board is being battered and tossed around in the mayhem. It blots out the sunlight and leaves me alone, breathless, and disoriented in the dark, until thwack! An unexpected blow to my stomach alerts me to another surfie also struggling to emerge for air. We both kick surface together, gasping but elated and on the adrenalin ride of our lives.
With just a few seconds to prepare for the next onslaught, I realise too late that I am fast approaching the river bank instead of maintaining a central position in the river. This is definitely not where I want to be. Tony's words come flooding back, "If you find yourself hurtling towards the rocks, turn your board to face the opposite bank and kick like your life depends on it." No kidding mate. Forty minutes later, totally exhausted, I crawl out of the river with my body still intact but my mind blown.
To be in with a fighting chance against this river you do need to be fit and fearless; it's definitely a workout from hell but worth every second of the pain. But for the guides, today's trip is like a walk in the park. Not content with just "going with the flow", they get their kicks from "squirting"; combining perfect timing, the flow of the water and their own skill in getting the most from their boards, they are sucked to the bottom where they surf the river bed. The experience of squirting lasts for as long as they can hold their breath, and then they abandon the board and shoot breathless to the surface.
So forget bungee jumping, skydiving or swimming across a crocodile lake; river surfing gives an adrenalin rush incomparable to other extreme sports. I'm definitely doing this again.
Getting there: From the UK, only Air New Zealand (0181-741 2299) flies direct to New Zealand from the these days, offering daily services from Heathrow to Auckland from December and onward connections to Christchurch on the South Island. But there are a dozen other airlines which will fly you there via intermediate points, ranging from Bangkok to Buenos Aires. Apart from the three weeks around Christmas and the New Year, you can expect to pay around pounds 700 for a return ticket.
Getting wet: The Serious Fun River Surfing Company operates in Queenstown from September to April. Trips last for half a day and cost around pounds 50, including hire of gear, tuition and transport. You need to be a strong swimmer and fairly fit, but you don't need to be able to surf.
Serious Fun: the company can be contacted at PO Box 564, 37 Shotover Street, Queenstown, New Zealand (00 64 3 442 5262; fax 00 64 3 442 5265). Alternatively, trips can be booked in person through the Information and Track Centre in Shotover Street, Queenstown. Serious Fun has a second river surfing operation on the Zambezi River at Victoria Falls in Zimbabwe. Similar trips to those offered in New Zealand cost around pounds 55. A half day of white water rafting with half a day of river surfing costs about pounds 90.
Further information: New Zealand Tourism Board, New Zealand House, Haymarket, London SW1Y 4TQ (0839 300900, which is a premium-rate number; fax 0171- 839 8929).