I closed my eyes and slowly swam forward with my right hand pressed against the side of the wreck. I knew that if I lost physical contact with the wreck, I would get completely disoriented and could end up getting turned around, making my exit virtually impossible. With my right hand on the side of the wreck, I waved my left hand around to try to feel something. I recalled hearing a crew member tell his dive buddy about this room, explaining that there would be a bunch of wooden shelves to one side of the opening leading out of the room. Now, my left hand came into contact with the shelves and my heart jumped. Carefully, I felt the space between shelves, and continued to move along slowly. Then, I felt nothing with my left hand, and I made a big circle with it. Still nothing. This had to be the exit! Excitedly, I swam forward and my head crashed into the back of what had been a large wooden dish cabinet. I could hear the dull thud.
I groaned in bitter disappointment and cursed in anger. I stopped what I was doing, allowing myself time to think and get control of my emotions. Pressing my right hand against the side of the cabinet, I backed up and continued my search, waving my left hand about, trying to feel for another shelf. I remembered that I had dropped into the room when I came in, and decided to swim higher up, and after I went about two feet up, I again continued searching for the exit, moving to my left. With my right hand pressed against the wall of the room, I came to a spot where my left hand felt nothing. I swam forward very slowly this time and alternated between putting my left hand in front of me like a football player stiff-arming a would-be tackler and then waving my arm in a circle. I still felt nothing. I kicked twice and moved forward without hitting anything. I opened my eyes and saw that I was in the passageway leading out of the wreck. A faint glow of green light from the water-filtered sunlight outside the wreck illuminated the escape route from the steel tomb. My heart jumped. Nothing had ever looked so beautiful.
Not long after my close encounter in the San Diego, an experienced wreck diver found himself in a similar situation in the hulk when he recovered a World War I–era rifle and then tried to exit the wreck. He was not as lucky as me, got hopelessly lost inside the silted labyrinth, and drowned. The victim was a crew member on a dive boat, and when his body could not be found, other boats came on the scene and their crews searched the wreck. After almost a week of searching, Hank Garvin calculated he knew where the body was, although it was in an area that initially seemed unlikely. Garvin found the victim, his body an unpleasant sight; the exposed facial flesh had been eaten away by various sea creatures and grossly distorted by the gases trapped under the skin, which had expanded and stretched the rubber dive suit. It took several more dives to cut an opening so that the distended body could be removed in one piece.
In spite of this fatality, and others like it, Hank Garvin and the rest of the old-time northeast-wreck divers still remained opposed to the use of guidelines inside wrecks. In Garvin’s mind, the only way to ensure a retreat from a shipwreck was to be thoroughly familiar with it. The dive-boat crewman who had died in the San Diego did not have a lot of experience inside the wreck, and he had never before been to the area where he had recovered the rifle. When he had tried to exit, he missed a key turn, and swam into another deck level that dead-ended.
When Chrissy Rouse and I spoke about this particular death and the other wreck divers’ refusal to consider using guidelines, Chrissy found it hard to believe. “The old boys think that more experience would have gotten him out of the wreck?” He scoffed in disgust. “Haven’t enough guys died inside of wrecks relying only on experience? A guideline’s the only sure way out. I don’t get why wreck divers are so closed-minded about using guidelines inside a wreck.”
Like me, Chrissy had experienced the value of a guideline firsthand, on a dive with his mother. At Ginnie Springs there is a thick, gold-colored permanent guideline into the Devil’s Cave System. Chrissy and Sue Rouse followed it and went through a restriction, a tight area, that required them to take off their tanks, push the tanks through the opening, and then wiggle their bodies through, to don their tanks again on the other side. Their struggles severely reduced the visibility. Soon, they could not see the line leading out of the cave. Chrissy and Sue hovered in the water, peering everywhere to see the guideline. They did not see it.
During their cave training, Chrissy and Sue had conducted lost-line exercises, both on land and in the water; the training gave Chrissy supreme confidence about what to do next. Using hand signals, he told his mother to hold the side of the cave while he went looking for the line. She obeyed, waiting in the low-visibility cave as her son deployed his emergency reel, tying it off on a rock outcrop next to her, and swam off with it. She believed Chrissy would find the guideline that would lead them both back to sunlight, yet she still felt an intense loneliness; her only company was the sound of her exhalations and the bright glow her light reflected in the sandy silt suspended in front of her.
The beauty of the lost-line drill is that it does not require that you find the entire way out of the labyrinth. Chrissy needed only to find the guideline he and his mother had followed in. By methodically searching the area, he was sure to come across the permanent line.
When Chrissy found the nylon line that led out of the cave, he tied off his emergency guideline reel to the permanent line and followed his emergency line back to his mother. Sue’s heart jumped when she saw her son materialize like a ghost from out of the glowing silt curtain in front of her. Chrissy flashed an “OK” sign with his hand and Sue automatically returned the signal. Chrissy signaled his mother to follow the line. Sue Rouse made a gentle O with her left thumb and forefinger around Chrissy’s emergency line so that she would have physical contact with the line, and she swam slowly but deliberately along its path. As she swam, Sue made sure to sweep her right hand over her head and in front of her like a windshield wiper, to prevent hitting her head on a rock. Chrissy followed his mother as she swam to the permanent line and found the way out.
To the nineteen-year-old it was a great adventure. Chrissy relished the stunned look on people’s faces whenever he told the story. People not familiar with cave diving and the lost-line drill were startled at Chrissy’s cavalier attitude and wondered if he was just displaying machismo to cover his fear. But Chrissy’s reaction was not machismo. It was the security of his belief in his own youthful immortality—combined with the rational confidence imparted to him by his dive training. He could not conceive of his own death inside a cave.
“God, Chrissy, that was scary!” his mother said when they got out of the cave.
“No, Mom, there was nothing to it.” Chrissy concentrated on taking his fins off so he could climb the wooden steps leading back onto land. “I know I’m not going to die in a cave. I’m gonna die wreck diving.”
Sue was horrified. “What? Don’t say that! I don’t want to hear that sort of talk!”
Later, Chrissy would tell me, “After what I’ve learned in cave diving, I can imagine how scary it would be deep inside a wreck without a guideline. It’s stupid to not run a line inside a wreck.” But that he insisted on saying that he would die wreck diving was odd. After this incident, Sue heard Chrissy repeat the assertion that he would die wreck diving. Why would he keep telling her such a thing? She brushed off her concerns. Perhaps it was just his childish way of getting her attention.
When the Rouses arrived at the Wahoo, I helped load their equipment onto the vessel. They had brought forty tanks with them, mostly scuba tanks they would wear during their dives, but also several five-foot-high green oxygen-supply cylinders that they would use to mix more gases if they needed them, or to transfer more oxygen into the tanks they carried for their oxygen decompression. This would be the first sport-diving expedition to the Andrea Doria using mixed gases—one of several reasons that the Team Doria expedition aimed to be significant for divers everywhere.
The scuba tanks that we loaded onto the Wahoo contained various gas mixtures, and each tank with anything other than compressed air was
marked with special stickers that listed the gas contents of the cylinder. The tanks with high-oxygen-content gases or pure oxygen were specially color-coded: green for pure oxygen, yellow and green for nitrox (a high-oxygen-content gas that also contains nitrogen), and orange for the small bottles of argon that we would use as an insulating gas to inflate our drysuits. Each tank’s sticker listed not only the composition of the gases in that tank but also the maximum operating depth at which the gas in that cylinder could be breathed. This helped prevent divers from breathing a high-oxygen mixture at too great a depth, then convulsing and dying from oxygen toxicity.
The most radical gases were the trimixes—helium, oxygen, and nitrogen. Helium-oxygen mixtures, known as heliox, had been used successfully for over sixty years by both commercial and military divers, but the use of trimix was something very new. Few divers or researchers had extensive knowledge of trimix gas or much practical experience in using it. Although mathematical calculations designed to predict its effects were theorized, what actually happened to the body during a trimix dive was still open to scrutiny. Theoretically, trimix gas was logical for breathing underwater, and made sense to me and the other divers I had asked to be part of Team Doria. Besides, the Rouses and I had been trained in the use of trimix gas by Sheck Exley, and if he could survive dives down to 867 feet using this technology, that was good enough for us. As we saw it, researchers would spend a lot of time coming up with a precise explanation of the physiology of how the gases were absorbed and eliminated from the body, but even then there would remain many mysteries, just as there remained mysteries having to do with the use of compressed air. If we waited until the scientific community got around to agreeing on the protocols for trimix gas, we would be old and gray and would have long since lost any chance to make deep diving safer or extend the depths at which we could dive.
Although Bill Stone and his team at Wakulla Springs cave had successfully used trimix on many long dives at depths down to 360 feet in 1987, it was still not completely clear which decompression tables worked and why, or how exactly the body reacted to these gases. Researchers wanted to know how the body would react to absorbing and dispelling two inert gases, nitrogen and helium. The different molecular weights of the gases could be input into computer models to generate decompression tables. But how effective would the decompression actually be in the field when it was applied to human bodies? And how effective would the decompression schedules be in the open ocean, where a diver might not be able to hold precise depths during decompression because of rough surface weather?
Researchers generally thought divers were crazy to risk the ravages of the bends, but at least two—Karl Huggins and Mike Emmerman—were eager to document the effects of the Team Doria dives on me, on the Rouses, and on the rest of the expedition divers. Huggins, who had monitored other groups on live-aboard dive trips, was a research associate in the Department of Atmospheric and Oceanic Science at the University of Michigan, served on the university’s Diving Safety Control Board, and was internationally known for his research on decompression theory. He had written the decompression algorithm that was used in the first widely popular diver-carried decompression computer, the EDGE, manufactured by Orca Industries, which came on the market in 1983.
The EDGE computer sensed the diver’s depth at frequent intervals, then calculated the amount of time that the diver could stay at that depth without having to decompress, based on the algorithm Huggins had developed. The EDGE used a microprocessor, a forerunner of the computing chips behind today’s powerful desktop computers. If decompression was required, the computer indicated the shallowest depth that the diver could ascend to—called the diver’s ceiling—without violating the decompression model. The original EDGE did not show all of the depths where ascent stops had to be made, nor did it show the time required at each stop. But it did show the total time required for ascent, and when the diver could go up to his next decompression stop, the ceiling indicator told the diver where to stop.
The EDGE made conducting dives much easier because it measured the diver’s actual depth in real time; it provided a custom decompression schedule based on the theoretical gas absorption calculated by the decompression model on that particular dive. Although the EDGE was a bulky piece of diving equipment—its rectangular casing easily took up the entire length of the forearm—the average diver was won over by a clever graphic display that showed how much nitrogen gas had theoretically been absorbed. At first, divers were leery of relying on electronics to make decompression calculations in the harsh underwater environment. The high price tag was also enough to make most of them sit back and observe the problems other divers might encounter when using the computer before taking the plunge to purchase one.
By 1986, there were more than five thousand EDGE computers in use by divers worldwide. It was a modest beginning, but soon the EDGE’s continued strong sales prompted other manufacturers to make use of evolving technology and bring smaller, more powerful diving computers onto the market. As the price tag on the EDGE dropped, its one real drawback, besides its bulk, was that it could only calculate dives down to 165 feet on which divers were breathing compressed air.
Huggins had become interested in researching the dives on the Team Doria expedition when his friend Mike Emmerman explained the scope of the project. I had invited Emmerman, a partner at the Wall Street-based investment firm Neuberger Berman, to participate in this expedition and conduct research. During the day Emmerman managed hundreds of millions of dollars in investment funds. His weekends, evenings, and vacation time revolved around diving. He conducted his own research on dive computers, focusing on the effects of diving after flying in commercial airplanes, and working to determine when it was safe to fly after diving. A commercial airplane cabin is pressurized to seven or eight thousand feet above sea level—less than one atmosphere pressure. This means that a person whose body is adapted to sea level is actually eliminating nitrogen during a flight. A diver who flies too soon after diving risks getting bent, even if he had no symptoms of decompression illness before takeoff.
With Chris, Chrissy, and me among the guinea pigs, Huggins and Emmerman—both trained Doppler technicians—would use the non-intrusive device called the Doppler ultrasonic bubble detector to record the sound of blood flowing through our bodies. It could detect any substantial postdive buildup of inert gas bubbles, which might lead to decompression sickness. The bubbles could be heard as chirps and rumblings, where the sound levels are categorized according to four degrees of severity. Generally, the more bubbles, the greater the potential for the bends. However, research had already shown that for some mysterious reason inert gas bubbles could be present in a diver’s body without any overt signs or symptoms of the bends. One theory about this phenomenon was that bubbles could form directly in the tissues, and would not be detected by the Doppler device, even though causing the bends. Therefore, the theory went, bubbles in the bloodstream were less important than bubbles in tissues. By documenting with Doppler the dives being done on the Team Doria expedition, our researchers hoped to begin building a database of actual trimix dives that might allow them to get an idea of the decompression stress divers were placing upon themselves. They would also make comparisons against dives where only compressed air was used at depth, and rate these with recordings made by other researchers on other expeditions.
On this expedition, we hoped there would be ample opportunity to compare numerous dives conducted with different dive tables, some of which were based on competing theories. Huggins had based his computer algorithm on a combination of John Scott Haldane’s early 1900s decompression theory and the updates that the U.S. Navy and the Pennsylvania Analysis of Decompression for Undersea and Aerospace group had made to Haldane’s theories, along with Doppler-based no-decompression limits proposed by Merrill Spencer at the Institute of Applied Physiology and Medicine in Seattle. Some of the more recent theories competed with Haldane’s, whereas others expanded on his work. The Schreine
r Model—a mathematical decompression model named after the man who had been Bill Hamilton and Glenn Butler’s boss at Ocean Systems—was one of those theories. Some divers would be diving using tables generated by Bill Hamilton’s computer decompression model, which were based on the research done by Schreiner, Hamilton, and others at Ocean Systems.
Randy Bohrer would be diving using tables generated by the computer algorithm he had written, which was based on the theories of professor and medical doctor Albert Bühlmann, at the University of Zurich, who had taken up the complex issues of decompression modeling as a hobby. Bohrer, an aerospace engineer who worked for Grumman during the day and researched computer decompression modeling in the evenings and on weekends, had run into the inevitable problems that decompression modelers run into, which led him to an alliance with Bill Hamilton. Bohrer had been retained as a consultant for a number of big dives, and had written the decompression tables for Sheck Exley’s world-record cave dive to 867 feet.
Earlier in the year, I had brought Randy Bohrer in on the diving-computer project I was working on as a consultant for the Japanese trading company Inabata. I had proposed creating an air computer first, then modifying the basic programming and tooling for that computer to manufacture a more sophisticated device that could calculate dives using nitrox—otherwise referred to as oxygen-enriched—gases. Eventually, I foresaw a third computer, which would calculate dives using trimix gases, but not before the sport—and the market—progressed and more divers used these sophisticated deep-diving tools.
The Last Dive Page 15