First they have you sign enough releases to waive all your own rights, plus those of your family and a few generations of your descendants. Then they strap you in the gear and use a crane to lift you, in a cage, to a height of 130 feet. Finally, you step out of the cage onto a tiny little platform, waaaaaaaaaaaaaaaaaay up there. Far enough up that the cheers, jeers, and cries of "Do it!!" from the spectators on the ground are noticably muted.

Then you dive off. Head first.

There are two whole seconds of free fall. Then, with maybe one second of life remaining, the bungees reach their limit. But at that point you're still accelerating, since the bungees have only reached their maximum UNstretched length. Tension then increases in proportion to the amount of extension in the cord, which can be thought of as a spring. When the tension matches your weight, you have stopped accelerating, but you've reached your terminal velocity, and you're still moving down. After that the tension begins to exceed your weight by increasing degrees, still in proportion to the total extension, and you begin to decellerate while continuing to move down. You reach the lowest point, maximum extension, maybe 20 feet above the ground. Your velocity is now zero, but you're experiencing maximum upward accelleration - perhaps three or four gees worth. Because your head is nearest the ground, the blood pressure there is now the highest in your body, like it would normally be in your feet, only you've also just multiplied this higher pressure by a factor of three or four. If you're at risk for strokes or aneurysms, you shouldn't be doing this.

Okay, from the bottom, you're now accelerating upwards. In other words, you're bouncing. Once you get up, you fall down and bounce again. And again. And again...

It was TERRIFYING!!!

But, of course, that's the whole point. I had a smug grin on my face the whole way home. :) :) :)