As I stood on the edge of the rail viaduct at Ohakune, a small town on the central plateau of the North Island in New Zealand, shaking, looking over the side at the muddy, rock strewn ground 50 metres (175 feet) below I wondered how on earth I’d been talked into bungy jumping.

There is definitely something to be said for not diving off a bridge attached to an elastic band which will send you back almost to the point you jumped from and eventually, after much soaring up and down, leave you hanging in mid-air. But here we were: at the end of a trip planned over a few beers. Brent at 16 is the youngest, the two girls Claire and Kathleen, Clive, Ross, Chris, Jeremy, Len, Brent's father Bill (at 49 the oldest) and myself.

I had to be talked into jumping after arriving and surveying the scene; cold, wet, and was that viaduct high; but peer pressure made sure I was jumping.

The first thing to be done was the weigh-in. Each person must be weighed as this determines how the bungy is adjusted so that everyone regardless of his or her weight falls the same distance. Your weight is written in ink on your hand and you are given a card with your name and weight on it which you give to the operator.

The viaduct itself is a massive iron structure with a wooden top that has been refurbished by the New Sensations Supply Company Ltd, run by A J Hackett (who gained fame in the late 80s by jumping off the Eiffel Tower in Paris) and Chris Allum. The new concrete bridge runs alongside.

Chris Allum and his team of helpers assured us it was as safe as falling out of bed. They haven't had an accident yet. This reassurance did not help. The shaking got worse.

When your name is called, you climb, or in my case stagger, over the guard rails of the viaduct and sit on a specially built platform where your legs are bandaged and strapped together. The girl who tied my legs together commented on my shaking. Lying I said I was cold.
The bungy, which is quite thick and is made up of a series of elastic strands all tied together is then attached to the strapping and you make your way to the jumping off point.

Chris drew the short straw and was first to jump. The blood-curdling yell he let out did not help me at all.

The girls were next, then Len, Jeremy and all of a sudden it's my turn.

I stand there looking at a large tree in the distance that I am supposed to dive towards while Chris Allum explains that the best way to launch yourself off the viaduct is to imagine you are going to do a belly flop into a swimming pool. The further out you dive the better the jump will be.

As he is explaining this he is also kicking my feet forward. It seems your toes have to be over the edge, not 10cm (6ins) back like mine.

All the people around the jump-off point do a countdown, loudly. 3-2-1-go

Shaking like a leaf I dive.

The speed of the fall is incredible. In five seconds you reach 116kph (70mph). This is how long you are falling before the bungy takes over and sends you shooting back up towards the viaduct.

Going up is just as bad as the fall as you are swinging around upside down traveling extremely fast and not really knowing where you are. Out of the side of one eye the bridge spars look awfully close.
When I stop at the top I dangle for what seems ages but is only about a second and a thought flashes through my mind. "Has the bungy slipped off?" Thankfully it hasn't.

I then plummet down again, almost but not quite, as fast as the first time. This happens five or six times. Eventually I end up hanging upside down about seven metres (25 feet) off the ground.
I am lowered down towards a guy holding a gaff, grab it and he pulls me down backwards onto a groundsheet. He then asks me how I feel. "What's the opposite of terrified?" I blurt out.

After being untied I wander over to the rest of the group with a grin on my face and we congratulate each other.

While watching Brent, Bill and Ross do their jumps I realize something; I am not shaking.