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February 01, 2007

More thoughts on caves

I am not claustrophobic, but I am not overly fond of dark, restricted places either. So I think the many thoughts I've been having about cave diving are triggered by the imagery I've seen in videos and pictures, that of wondrous, wide open underwater caverns, brightly lit. And probably equally appealingly by a video I saw where two cave divers used scooters to negotiate a video game-like run inside bright and very smooth underwater tubes. Up, down, left, right, it all seemed like a fun, otherworldly game.

The reality, I am certain, is quite different. And I continue to say that as someone who has no cave diving experience whatsoever. The closest thing I've ever come to it were two dives into cavern-like environments, but those did give me an idea. Then, of course, I've been reading a lot.

My early literary excursions covered a lot of wreck diving. Invariably, the experienced wreck diving teams would be joined by a cave diver, or a cave diver group wanted to try their hand at wrecks. I've previously mentioned the odd apparent rivalry between the two groups, each viewing the other with suspicion and a degree of condescension.

Wreck divers felt cave divers were cocky braggards who thought they knew everything and blindly used and trusted whatever they had learned in the caves. They criticised the use of lines inside wrecks as opposed to the wreck divers' practice of familiarizing themselves thoroughly either via blueprints, or by entering in stages, never penetrating deeper until they were thoroughly familiar with a layout. Lines, they felt, could break or, worse, ensnare divers. Likewise, they quickly termed the self-locking carabiner clips used by cave divers "suicide clips." And they had a point. In caves, there is rarely ever anything where a self-locking clip can pose a problem whereas its quick one-handed operation can come in quite handy. In wrecks, they can easily snap onto a myriad of things.

Cave divers, on the other hand, often saw wreck divers as clueless, reckless adventurers who blindly charged ahead instead of methodically planning their dives. They pointed to a lack of proper equipment and planning as opposed to their meticulous preparation. And cave divers bemoaned what they perceived as ostracism by the open water diving community in the 1960s.

As of late, I've been reading more on cave diving, and that has opened my eyes to the different mentalities.

Wreck diving can provide the thrill of discovery when locating a wreck, the thrill of identifying it if it hasn't been identified before, the prospect of finding treasure or at least retrieving artifacts, the morbid thrill of seeing the silent remnants of tragedy, the challenge of penetrating a dangerous place, and perhaps the scare of being confronted with remains.

Cave diving seems entirely different. There is the adventure of entering dark, dank places that can bring unexpected beauty, the challenge of conquering one's fears, but most of all, in the case of advanced cave divers, the prospect of going where no one has gone before. That is a challenge both to the novice who is going where s/he has not gone before, and to the advanced diver who seeks to explore "virgin" cave and mapping it out. The thrill of that seems to be the primary motivation of cave divers.

Reading Sheck Exley's "Caverns Measureless to Man" and "Taming of the Slough" both reveal numerous clues as to the nature of cave diving. Exley, for example, had a fear of heights and was prone to seasickness. He mentioned feeling uneasy in such inoccuous places as diving over the canyon-like wall of the underwater sink of Kings Bay at Crystal River, though it is only a couple dozen feet deep, and descending into "sumps" on a chair where in the darkness he pretended it was just a few feet, and not the vast distance it actually was. Or that he always felt butterflies in his stomach when he was in a restriction underwater and couldn't see.

Exley personifies the ultimate cave diver. He was both meticulous and responsible in his planning and execution, as well as the ultimate dare devil. His love of cave diving made him participate in writing rules and regulations so cave diving would not be outlawed in light of the numerous deaths. He went as far as being on the board, or chairing, not one, but several cave diving associations at the same time. He continually points out advances in safety, and is proud of the methodical development of systems and procedures that enabled safe explorations. He prioneered the "rule of thirds" where you use one third of breathing gas for penetration, then return with two thirds remaining. That gave you a third to track back, and a third reserve in case something went wrong or it took more time to find the exit. That rule was extended with the use of "staging." They'd take along additional bottles, breathe from them until they were down by a third, then drop them and either switch to the next bottle, again breathing it down to a third, before finally using the big double tanks on their backs, again breathing those down to a third before returning. That way, even at the farthest point of penetration, they'd always have 2/3rd of their gas remaining. On the way back, if all went well, they'd actually have more and more gas left. Theoretically, the main tanks would still contain a third by the time they reached the stage bottle left behind last, they'd then breathe that down to a third before reaching the next bottle, and so on.

Cave divers are also very proud of their overall contributions to the sport. Exley states that numerous improvement to scuba equipment came directly from the quest for record dives. That includes such things as forearm knives and dual valves, but also essentials like octopus regulators and buoyancy compensators. Buoyancy Compensators were invented by cave divers? I found that hard to believe, yet Carol confirmed it. I remembered Exley writing how in their early explorations they'd taken along Clorox plastic jugs and filled them with air from their regulators to provide the proper buoyancy, which is extremely important in caves. Why? Well, in open water the primary concern is not to descend or ascend too quickly, but going up and down a few feet is no big deal. In caves it's different. If you negotiate a cave only four or five feet tall, it's often essential to neither touch bottom nor ceiling as that could stir up silt and other particulates that can instantly reduce visibility to almost nothing. So proper buoyancy can be a matter of life and death.

Exley himself describes several situations where he felt he was facing death. Most came early on where he got lost, but was already experienced (and lucky) enough to find a solution and escape with his life. One was so extreme and unlikely that he conjectured it was impossible that he had survived that and perhaps he was already dead and simply did not know it. What makes him so compelling is that he seems both driven and totally cool-headed at all times. He was also a very good writer who not only managed to bring each of his dives to life but also provided insight and perspective.

"It had been an exhilarating dive, but somehow it was not enough. It never is." he wrote after they had explored an additional 1474 feet upstream into the Manatee Spring cave system to a then-record penetration distance of 3956 feet.

Exley writes that "every field of human endeavor from tiddly winks to space exploration has its champions and its marks for human endurance and achievement. Without them there would be little or no human progress, for we would have nothing to measure our efforts by or to encourage us to try harder." Yet, he's also aware that the public generally appreciates such endeavors only "as long as they are accomplished without unnecessary risk." Some things simply don't make sense. Exley was both driven to accept extreme risks, and to rationalize them and make them as safe as possible. He was aware of his mortality, repeatedly mentioning his own advancing age (even when he was just over 30 years old) or pointing to what he believed was increased susceptibility to decompression sickness once past the age of 40.

Unfortunately, cave exploration is a game with limits. Unlike the ultimate dream of every cave explorer -- that the farther he goes, the bigger the endless labyrinth gets -- reality is different. Once a cave system has been fully explored, the game is over. "The unconquerable was conquered," wrote Exley after they seemingly had explored every inch of the Manatee Spring system. "We were happy with our achievement, but we felt a sense of loss. Now there would be no future expeditions in the Manatee Springs Cave System, no renewal there of that strange yet somehow intimate companionship of divers and impossibly remote, virgin cave." (to the left is a picture we took at the entrance to the Manateee Spring caves at Catfish Hotel Sink, almost exactly at the same spot Exley took a picture, shown in "Caverns") Or, "Maybe it just goes on forever," as Exley marveled after a record penetration of 10,939 feet at Cathedral in Florida, a place he so loved that he bought the property that included the primary entrance into the system. Those words speak volumes. It's about the quest, the exploration of the unknown. Caves are finite, and thus conquerable. Just like reaching the moon is a finite goal. Mankind did it, then lost interest, settings its sights to the next goal. Mars became the next cave. Ironically, Exley had not reached the end of the Manatee Springs system. After his death, others found a side passage he had overlooked and that led to several thousands of feet beyond what he had found (Read about Jarrod Jablonski's 1994 record exploration).

Perhaps it was the finite nature of cave penetration that led Exley to seek depth records as well. "On deep dives you move into the physiological and psychological unknown, where all the components of the air you are now breathing become poisonous, where the normal problems associated with scuba diving in caves are magnified a hundredfold, where bizarre disorders arrive that medical scientists have never even dreamed of." This is where things begin to get extreme. Exley dove deeper on compressed air than most, yet there was a limit and he had to switch to various blends of trimix, something that was poorly understood at the time, for which there existed almost no decompression tables, and the investigation of which claimed the lives of some of the best cave divers.

Exley, as always, was both scientific and philosophical about it all. The secret to setting cave diving world records over a period of over 20 years and live to tell of them was what Exley termed "controlled paranoia." He always assumed that the cave was both an enemy and a friend, someone both out to get him and give him some of the greatest pleasures in his life. So he used the paranoia to meticulously think through every conceivable potential hazard and came up with solutions and backup procedures. But he used his love of caves as a means to reduce the anxiety. Once he began descending to 500 feet and beyond, it was all virgin territory. Most of the equipment simply could not take the pressure. Dive lights collapsed until they discovered it was better to pre-flood them with distilled water. Available depth gauges didn't work at all below 500 feet, and depth was measured only by the length of the line and the observed angle of the cave. Regulators proved inadequate until he settled on a Poseidon Odin. Expensive dive watches got crushed and Exley found that cheap Casio wristwatches that were merely labeled "water-resistant" to 335 feet did the job much better. Gas impurities could quickly become lethal at such pressures. Testing the various gas mixes was an issue, as was labeling the tanks so there would be no mistakes. There were reports of "vestibular hits," some lethal, when switching back from helium to a gas with more nitrogen, something Exley tackled by carefully taking alternate breaths from different bottles. The amount of gas required was enormous as a full tank lasts only a couple of minutes when exposed to pressures of almost 30 atmospheres.

His planned record dive at Nacimiento del Rio Mante required a whole new design, a wrap-around set of five tanks, plus two stage bottles snapped to the chest and four more tanks left at various depths. Descending as fast as possible was a must so as not to add to the already endless decompression time. Even for Exley, breathing became like sucking liquid through a straw. He did go down to 867 feet in just over 20 minutes, then ascended to the first of 54 decompression stops at 540 feet. All in all, the ascent took over 13 hours with all those stops.

Unfortunately, in the end these were caverns truly measureless to man, and Exley perished below 900 feet in Xacatun, a different sink hole said to be almost 1,100 feet deep and not far from Mante, on April 6, 1994 at the age of 45. A detailed accident analysis is available at http://iucrr.org/aa.htm under "Misc. Incidents."

Thinking about it, there really is a huge difference between caves and wrecks. Caves are confined spaces underground. They are age-old, often millions of years, and hardly change. Wrecks are of human origin and tragedy. They age and change. Within years they can deteriorate from almost intact vessel to a pile of rubble hardly bearing a resemblance to a ship. And all too soon they will be gone forever. The quest becomes learning as much as possible while the wreck diver can. And the challenge of an ever-changing, always dangerous environment. Cave divers have to contend with the dark, the fear of getting stuck or running out of air. Wreck divers descend through the vast waters of the ocean or a lake, and it's getting entangled that presents the challenge and danger. Cave divers, especially those in virgin territory, never quite know how deep they'll go, and how they need to negotiate deeper and shallower areas. That figures large in decompression requirements. Wreck divers have it easier that way. Go up after the predetermined time, then decompress.

Posted by conradb212 at February 1, 2007 11:07 PM