NINE
IF THE 1984 PE?A COLORADA EXPEDITION made Bill Stone a sadder but wiser leader, it also fostered a scientific breakthrough that would help transform not only cave exploration but all recreation, work, and science that required time underwater.
The truth was that the mutiny didn’t really end the expedition; conventional scuba technology, reliant on air-filled tanks, had done it first. So much diving was required just to get to the known bottoms of giant caves that by the time explorers reached virgin territory, they were essentially out of air. The Pe?a Colorada expedition, the most ambitious dive exploration attempted up to that time, was a case in point. Stone’s team started with seventy-two tanks. Many of those were used just getting to and from Sump 7, leaving few for exploring the terra incognita that was this expedition’s reason for being. Stone knew that without some radically different diving technology, supercave exploration was finished. The problem was, that technology did not exist.
Actually, it did exist, sort of, but only for navy SEALs and their like, as one of the members of the Pe?a Colorada expedition explained to Stone toward the end of that effort. He was a pioneering U.S. Navy captain, diver, and medical doctor named John Zumrick. Stationed at the Navy Experimental Diving Unit (NEDU) in Florida, Zumrick shared Stone’s passion for cave diving. He also shared Stone’s frustration at finding themselves so close, and yet so far, from linking Pe?a Colorada with Huautla above. At the expedition’s end, therefore, Zumrick suggested that Stone abandon traditional scuba gear and look into devices called rebreathers.
To greatly oversimplify, a rebreather uses chemicals to “scrub” carbon dioxide from a diver’s exhaled breath, which it recycles over and over, producing dramatically longer dive times. Again to oversimplify, a single standard scuba tank gives about twenty minutes of dive time at 100 feet. A rebreather can provide hours.
Rebreathers in one form or another have been around since the 1600s, when a Dutchman named Cornelius Drebbel invented the first navigable submarine and then had to create a crude rebreather system to keep crewmen from suffocating aboard his oar-powered, leather-hulled submersible. (He heated potassium nitrate in a metal container, producing oxygen and also potassium oxide, which absorbed carbon dioxide.) Three centuries saw gradual and minimal improvements to the concept. Primitive rebreathers allowed a small number of sailors to escape from sunken submarines during World Wars I and II. But there being no major market demand for better rebreathers—crew escapes from sunken subs were tragic but few—rebreathers did not get much better.
Talking with Zumrick, Stone saw in a flash that rebreathers were the future of supercave exploration. But in 1984, there were no rebreathers for civilian use. Military units were exorbitantly expensive and were useful for only short, shallow dives, there being little tactical need for greater depth. Cave divers sometimes went very deep (Clark Pitcairn had hit 180 feet in Pe?a Colorada), and expeditions required dozens of hours of dive time. In addition, because they were for use in open water rather than in “overhead environments,” as divers call caves, the military units lacked redundancies Stone believed essential for cave diving. Finally, navy rebreathers, Stone felt certain, were not tough enough to withstand the harsh beating for weeks on end that expeditionary caving would deliver.
It was a challenge for which Stone was perfectly equipped by nature, education, and training, with that Ph.D. in structural engineering and his diving experience. He started investigating rebreathers literally the day he arrived home from Pe?a Colorada. Thus began a ten-year project that would run parallel to his extreme caving efforts. When he was not in a cave, he was up to his elbows in prototypes in his basement workshop. He rose daily at 5:00 A.M., worked on the rebreather for three hours, went to work, came home, kissed Pat and the kids, and disappeared into the basement again.
He had to overcome obstacles that had frustrated many other attempts. First, the new unit had to survive caving’s battering. Second, it had to be small and light. Third, it had to be absolutely fail-safe, because the supercave environment was less forgiving even than deep oceans and outer space. Open-water divers have access to recompression chambers and medical services. Astronauts on space walks can pop back into their vehicles. Miles into a supercave, divers enjoy no such safety nets. And, oh yes, a cave-exploration rebreather had to afford dive times then simply unimaginable.
Stone named his creation FRED, for Failsafe Rebreather for Exploration Diving. FRED’s gestation was often agonizing. Weeks sometimes passed without progress. Finally Stone would turn off the phone and go into seclusion. Day after day and for not a few nights, he sat alone in the basement, drawing, doodling, racking his brain, climbing the walls. Eventually came the “Eureka!” moment.
If he was having success slowly but surely downstairs, things were a bit less joyful upstairs. For one thing, he was pouring hundreds of thousands of dollars, some borrowed, some personal, into FRED. For another, during these years, the outside world was not all that he was blocking out. Pat, as well as the kids that started coming along, got less and less of his time. Regardless, he worked like this for three solid years, and on December 3, 1987, he rolled out his first prototype—literally—using a dolly and a friend to move the 205-pound behemoth FRED from his truck to the clear water of Wakulla Springs in Florida.
Size was not FRED’s only unique quality. He—sorry, it—was unlike any other rebreather, ever. For one thing, FRED was really twins. There were two complete computerized systems, and each could do everything independently. In addition, FRED was the first to use volatile but efficient lithium hydroxide as its scrubber.
Stone had to strap himself to FRED in the water, but he did not sink like a man tied to a boulder because he had designed FRED to be neutrally buoyant. One test diver later said that using FRED was like diving with a Volkswagen on his back. That was an exaggeration, but FRED was bigger than a Volkswagen’s engine and weighed about the same. In Florida, Stone made a nicely controlled descent to the bottom at about 35 feet, opened a book, and prepared to stay for a while. A long while.
Though he was using one of the best diving dry suits available then, after twelve hours underwater Stone was cold. He asked other divers to bring lead weights, which he carried while running up and down a steep underwater sand slope. Repeating the process periodically to generate warmth, he finished his first book and started another.
After twenty-four hours of this, Stone finally surfaced, setting a new record for underwater time using scuba gear by a wide margin. His creation, two hundred times more efficient than traditional scuba equipment, had scored a historic triumph. Amazingly, he had used only half of FRED’s capability for this experiment. With the other half enabled, Stone could have doubled his underwater time. His only real challenges had been staying warm and awake. Near the end, a diver and physician friend named Noel Sloan (who would later play a key role in Stone’s tragic 1994 Huautla expedition) helped Stone stay alert by kicking him whenever he nodded off. (Well, there was one more challenge: at one point the urine receptacle in the dry suit ruptured, so Stone spent the final hours underwater sloshing around in his own pee.)
At 205 pounds, though, FRED was useless for cave diving. Stone put FRED on a diet, refining and miniaturizing system after system. By 1989, the 105-pound MK-II appeared. It would still have to be carried down into caves in pieces and reassembled for diving. But once in the water, this son of FRED would be the answer to a dream.
As an interesting aside, all this time, the U.S. Navy had been working on its EX-19, a rebreather it hoped would allow dives to 450 feet. Despite having an oceanic budget and unlimited manpower, the swabbies came up dry. During a 1984 test, their unit sprang leaks, disabling the electronics. Rumors circulated about EX-19 divers blacking out underwater. After ten years, having spent more than $10 million, the EX-19 was deep-sixed.
Stone, working alone and on a shoestring budget in his Doc Savage basement laboratory, accomplished what the United States Navy could not. How did he do that? As Albert Einstein proved, everything depends on your point of view. Most people would say it was a combination of incredible drive, ingenuity, unshakable confidence, and great financial risk, and they would be right. Stone himself saw it as motivation powered by excitement, enabled by scientific expertise, and, more than anything, driven by relentless focus on a lifelong mission. He would be right, as well.
By 1989, Pat Stone had gone on her last expedition with Bill. In 1985, she began her professional career as a registered physical therapist with the Shady Grove Center for Sports Medicine, not far from their home in suburban Maryland, a position she would hold for seventeen years, specializing in orthopedic rehabilitation. By 1989, Pat’s answer to the question of how Stone made such a stunning technological breakthrough would have been different, because when he was not down in the basement with FRED, or at his government job, or doing test dives in Florida, he was going on cave expeditions, and her answer, while less lauding, would be as accurate as any of the others.