It is a view that inspires fear as well as wonder. Nearly 40 per cent of the club's customers have second thoughts about jumping once they have been winched up in the dark blue steel cage, whose sturdy but airy construction does nothing to hide how far down the river runs below them. The club's instructors are well-versed in prompting these would-be jumpers to have the third, fourth or fifth thoughts that give them the will to pitch head- first into space attached to an elastic length of bound latex the width of a scaffolding pole.
Only 1 per cent of the club's customers ask to be winched down again without jumping. "These," says Mark Debenham, the club's manager, "are the really brave ones." Coming down without jumping to endure the sympathy of your expectant friends is more daunting than the jump itself.
Bungee jumping is based on an ancient tradition - Pentecost islanders in the South Pacific marked their manhood by casting themselves from bamboo towers tied by the ankles to vines - but was devised only 17 years ago, when a group of Oxford University undergraduates formed the Dangerous Sports Club and took to jumping off high bridges on the ends of lengths of bound elastic. What began as their daredevil jape is now big business, developed by Antipodean entrepreneurs into a sport with codes of practice, national associations and jumping centres in Australia, New Zealand, Europe, Africa and North America. These centres each have their own ethos and there are competing schools on how the sport should be spelt - bungee, bungy or bungi. Chris Allum, a New Zealander and one of the leading promoters of the sport, has a business card with the legend "Keeping the Y in bungy".
The UK Bungee Club moved in February last year to Adrenalin Village, their Thames-side base, which is rented on an annual lease from the receivers of Battersea Power Station. On weekend jumping days, you find your way to the club's Portakabin premises through the spread-out wares of a car-boot sale. Before jumping, you must pay to join the club, sign an injury disclaimer and have yourself weighed.
Your weight is written in felt pen on your hand and becomes part of a mantra for the bungee operators. The strength of rope you are attached to by ankles and waist is gauged by your weight and coded by colour. When you enter the lifting area - where the operators fix the waist harness and ankle strap, as they follow you hopping with bound ankles to the cage and then accompany you in the lift - they read off and repeat your name, weight and rope colour. It is part of the safety procedure but also of the concentrated instruction and reassurance that distracts nervous jumpers from feelings of vertigo as the cage is winched rapidly into the air.
When the cage reaches jumping height, the gate is opened, the operator repeats safety checks and instructions once more and all of a sudden you are in mid-air. In the split-second before gravity takes effect, it feels as if you are hanging, suspended by a thread.
As the fall begins, a great rushing of air can be heard, and the whoops of encouragement from people waiting on the ground. The free fall lasts less than two seconds, the jumper reaches 60mph and feels a g-force equivalent to heavy braking in a car travelling at 20mph. When the rope cuts in, the pull back on the first bounce is almost 80 per cent of the start height. As the rebounds grow milder, the crane driver swings and lowers the cage over the embankment and other bungee operators catch the jumper or jumpers (tandem jumping is popular) and pull them on to a large cushion to recover.
The metaphors most regularly associated with the subject - sex, death and ecstasy - are part of the common vocabulary of mood-altering activities. The cocktail of bungee gets an extra shot when the blood left behind in the free fall catches up with the front of your head and feels fit to burst from your brows. It is part of the experience that leaves most participants gibbering with excitement after making a jump.
That rush of blood to the head is one of the issues at the heart of the debate about the health risks associated with the sport. In one recent case that received much publicity, a young girl was found to have suffered temporary tunnel vision after making a bungee jump. But the medical report concluded that the patient could have suffered similar symptoms from sneezing or from jumping the last steps of a flight of stairs. It is a fast and exhilarating sport and people cannot jump if they are under 14, have high blood pressure, a heart condition or a damaged back. The UK Bungee Club follows the code of conduct - including the requirement that jumpers are attached to the rope by both the ankles and the waist - of the British Elastic Rope Sports Association, a group set up in 1989 by the Health and Safety Executive.
When I visited Adrenalin Village, there was a party of 20 from the South Coast doing sponsored jumps for charity; a medical student back for a repeat visit who chose the catapult option, in which you are pulled out over the river by the bungee rope; a youth who jumped wearing strait- jacket and hood; a girl who thought better of following her boyfriend's jump and was swamped by wailing, hugging supporters when she was winched down; and a visitor from Italy, Raimondo Irace, who used his experience of cliff diving on the Amalfi coast to launch himself in a poised manner from the platform and to keep balance in flight on that dramatic first bounce.
Bungee acrobatics is now a competitive sport and most of its leading practitioners were formerly high divers or gymnasts. For the last two years the sport has featured in the Extreme Games held in New York State; and in November the top 30 jumpers will be going on a world tour organised by Triple C Sports Management, with planned stops at jump sites at Cairns, in Australia, Las Vegas, Victoria Falls, and at the Viaduc Soulevre, in Normandy.
The European Extreme Bungee qualifier for this year's Extreme Games was held at Adrenalin Village. The spins and somersaults of these performers are worlds away from the modest swallow dive of the first-time jumper but, for the rest of your life, recalling the memory of that initial leap is guaranteed to give you an adrenalin-driven frisson.
Six elastic sport sites around the world where jumpers can leap new frontiers
UK Bungee Club, Adrenalin Village, Battersea Wharf, Queenstown Road, London SW8 4NP
Telephone 0171-720 9496
The only permanent bungee jumping site in the United Kingdom, opened in February 1995. Jump platform is suspended from a crane 325ft above the Thames - twice the height of most mobile platforms. Home of European qualifying for Extreme Games in 1995 and 1996. UK Bungee Club offers jumping Sat-Sun, 10am-6pm; and Thu-Fri, 1pm-6pm during summer. Also organises mobile jumps and night jumps for groups. Motto: "You can't beat a BJ."
Cost: Club membership pounds 15; first jump pounds 35; second jump on the day pounds 25. Free for those jumping for charity who raise a given minimum sum.
New Zealand: Queenstown - AJ Hackett Bungy (Kawarau) and AJ Hackett Bungy (Skippers) Tel: 00 64 3442 7122; Pipeline (Skippers) Tel: 00 64 3442 5455
Playground of bungee dreams, with plenty of options if you get bored with plain old leaping. Some of the favoured boredom-breakers include leaping buck-naked, dressed in leather (complete with whips), and attached to skis or snowboards (above). For the ultimate day out, the Awesome Foursome incorporates a bungee jump, jet-boat river ride, helicopter ride and white- water rafting.
Cost: Kawarau, NZ$99 (43m jump, plus T-shirt); Skippers, $110 (71m jump and transport, plus T-shirt); Pipeline, $130 (102m jump and transport, plus T-shirt). Awesome Foursome, $299 (transport included).
Australia: AJ Hackett Bungy, Cairns (two sites - Cairns Rainforest; Kuranda Market). Tel: 00 61 7031 1119
The Rainforest site is reputedly the busiest in the world. Jumpers climb 247 steps to the top of a purpose-built tower modelled on the bottom section of the Eiffel Tower (above), then dive off the 45m platform towards a creek below that winds through the forest floor. The Rainforest averages 100 jumps a day, with 125,000 having taken the plunge in six years - 100 per cent safety record at Australia's only safety standards-approved site. Like many sites, they are experienced in aiding physically disabled take the plunge - sometimes wheelchair and all.
Cost: Rainforest, A$95 (45m jump and transport plus T-shirt); Kuranda $100 (jump, T-shirt and video).
France: Vertige Aventures, Ponsonnas and Le Sautet, near Grenoble. Tel: 00 33 76474280
Le saute en elastique offered at two bridge sites (103m and 95m respectively), which have attracted more than 80,000 jumpers. Organisers divide the jump into four stages: Preparation ("la pression monte"), emotion ("sur le parapet du pont"), action ("le grand frisson") and recuperation. Combined activities include mountain biking, bobsledding, hydro-speeding and whitewater rafting.
Cost: UK Bungee Club organises return weekend trips by Channel ferry from Adrenalin Village, in London (details above); pounds 219 for summer itinerary; pounds 199 in winter. Group discounts offered.
Zimbabwe: Bungi Extreme/Shearwater Rafting, Victoria Falls: Tel: 00 263 13 4471
Situated on the bridge linking Zimbabwe and Zambia, the African experience is one of the wonders of the modern world. With a backdrop of the waterfall, jumpers leap off the woodwork, affectionately known as "No Man's Land", and into the gorge, plummeting towards the Zambezi River. They are then winched back up. The site is 3km from Victoria Falls township, and though transport is readily available, walking the route is the popular choice of visitors. As well as a dose of courage for the great leap forward, you will need your passport to make it through border controls at the bridge.
Cost: US$90 (111m jump).
United States: Oak Beach Inn Bungy, Long Island, New York. Tel: 001 516 587 3670
It is not an easy road to travel for US commercial operators, says Chris Allum, the president of the North American Bungy Association. "Americans are 'sue- happy', and that means insurance premiums take up one-third of the cost of each jump. That doesn't leave much for the owner," says Allum, aged 46, a veteran of 3,000 jumps, including a world record leap in West Virginia (above). Some 200 sites operated in the US in 1991, but that is now down to 17 full-time venues. Allum's Long Island site, open in spring and summer, is from a crane, with bounders leaping out over the Atlantic.
Cost: US$69 (43m jump); $15 each for T-shirt, video.Reuse content