Rebreathing Lessons

Unique breathing devices now enable us to live in totally alien environments, as though we were creatures of a different world. Sounds like something the apostle Paul said 2,000 years ago.

Oxygen toxicity.

If you have it, you have either a pulmonary condition resulting in damage to the lungs and airways or you have central nervous system toxicity characterized by convulsions with little or no warning signs.

Either way - if you are a deep-water diver - you're in big trouble.

That's why Bill Stone began to work on a cutting-edge diving device called a "rebreather." This is not your father's scuba gear.

In 1987, he made diving history.

He began by immersing himself in 30 feet of water, deep down in a network of submerged caves in northern Florida, carrying only two 30-cubic foot oxygen tanks and a sack of "blood and gore" war novels.

Had he been using normal scuba gear, he would have been forced to surface after 30 minutes. But Stone, an automation engineer at the National Institute of Standards and Technology in Washington D.C., was wearing a homemade rebreather.

So down in the water he stayed, for one hour, two hours, 10 hours, 20 hours ... just plowing through his stash of...