Beyond a certain point even Olympic form won't save you. One expert claims the upper limit for surviving water entry is around 80 mph. Presumably it's less if you're hitting something solid. Still, the literature teems with spectacular exceptions:

* In a 1942 paper, physiologist Hugh De Haven told of eight people who survived falls of 50 to 150 feet on dry land, many with only minor injuries. The common denominator: something to break the fall or soften the impact, such as loose dirt, the hood of a car, or, in one astonishing but verified case, an iron bar, metal screens, a skylight, and a metal-lath ceiling.

* In 1963, U.S. Marine pilot Cliff Judkins's chute didn't open after he bailed out of his crippled fighter. He fell 15,000 feet into the Pacific, suffered numerous broken bones and a collapsed lung, but lived.

* U.S. Army air force sergeant Alan Magee fell 20,000 feet from an exploding B-17 in 1943 and crashed through the skylight of a French train station. (A lesson emerges: Aim for the skylight.) Though his arm was shattered, he lived too.

* When his bomber was shot down in 1942, Soviet lieutenant I.M. Chisov fell 22,000 feet into a snowy ravine. He was badly injured but recovered.

* Luckiest of all was RAF flight sergeant Nicholas Alkemade, who leaped from his burning bomber in 1944 without a parachute at 18,000 feet. After a 90-second plunge, he crashed through tree branches in a pine forest and landed in 18 inches of snow. His only injuries: scratches, bruises, burns, and, in some accounts, a twisted knee.