February 26, 2007
More diving, finally!
It seemed like it had been forever since my last dive trip when I packed my bag for a late February trip to Northern Florida. Essentially I retraced the steps from my trip last fall, but added some new twists. In addition to just getting back underwater I wanted to learn more about caverns, learn drift diving, and do a lot more underwater photography.
By now I have read so much about caves and caverns that I am both intrigued and scared. I am also neither cave nor cavern certified (yet) and so can, legally, only get a glimpse of that special world. Fortunately, that is possible in the springs and sinks of northern Florida. There are even places where you can enter caverns with just an open water certification, such as "the cathedral" at Ginnie Springs. However, this sort of thing is not sanctioned by PADI or NAUI and so it all becomes an issue of signing waivers, knowing what you're doing, and not engaging in needless, and potentially deadly, risks. And I wasn't going to do any of that. Still, I knew that no matter what diving experience I'd have, it didn't matter. I just wanted to again feel the rush of being submerged, of floating weightlessly, of seeing and experiencing this different world that has opened to me and has been captivating me ever since I came across it. So I packed all my gear, hoped it would all make it okay, put all the essential stuff like regulator, dive computer and my cameras in a carry-on. That left very little space for clothes. Turns out, of whatever little I took, half I never even used. Divers don't need much in terms of clothes. A few pairs of socks, enough underwear (I use them under my wetsuit instead of bulky bathing suits), a pair of jeans, sneakers and a few T-shirts, is all.
Turns out all went well. My big dive bag made it to its destination and came around on the baggage carousel just as I walked up to it, fresh off the plane. Yeah. It had been opened and inspected by our friends from whatever US security agency is running our lives at airports these days, making sure we don't take little fingernail scissor and more than three ounces of toothpaste with us. Amazingly, my carry-on chuck full of electronic gear and hoses and housings and power supplies and cameras and wires and other exotic stuff was never questioned nor opened whereas my sneakers and Gateway laptop were suspiciously sniffed as potential terrorist materials.
Back at Devil's Den
Devil's Den will probably always hold a special fascination for me. It's where I began my NAUI advanced diver training for one thing, and it's a great place to dive. The setting is wild and picturesque, and though the crystal clear blue-green water of the sink itself looks so shallow, it's really not. The entrance through sheer rock and then a careful walk down a set of wooden stairs onto a platform on top of the debris cone in the center of the round surface of the sink lets you enter a wonderfully mysterious world.
Before we made it there I'd been afraid I'd have forgotten how to assemble and put on my scuba gear, but it all came back immediately. Maybe it is a bit like riding a bicycle. It was a beautiful day, sunny and warm without being too humid. My wetsuit went on a whole lot easier and even getting down all those steps in the full scuba gear seemed much less of a struggle than last Fall.
This time I'd brought along a different set of cameras, four in all, and for this first dive we chose the two very different models from Olympus. In fact, they couldn't have been any more different. The Evolt 330 digital SLR resides in a massive housing, its external flash has its own large housing, and the two are connected via a hefty, heavy metal bracket assembly that lets you twist and turn the flash any which way you want. I'd spent several hours going through the Olympus manuals, one each for each part of the vast assembly, and a few more acquainting myself with the whole setup. I concluded it'd be best to pretty much leave all settings on as automatic as possible. Once all geared up I also decided to let Carol with all her NAUI instructor expertise and experience in underwater shooting take a first crack at the Evolt (okay... she didn't have to twist my arm when she offered to carry the heavy rig down into the cavern) so that I could get used to it all again.
Me, I took along the waterproof Olympus 770 SW instead. As much attention as the massive Evolt setup in its clear acrylic housing and all its shiny buttons received each time I pulled it out and set it up, the little 770 was an even bigger attention getter whenever we unceremoniously plopped it into the water. Onlookers' reaction was always the same: they thought I'd neglectd to put the camera into its underwater housing, or simply forgotten to leave it onshore. Then it was on to explaining that this sleek little camera didn't need a housing and could, in fact, handle depths of up to 33 feet as it comes out of the box.
This time Devil's Den was fairly busy with perhaps eight to ten divers but the place is large enough for that not to be a problem. We carefully submerged the Evolt to test it for telltale bubbles that might indicate a leak. There were none. Ditto for the separate flash housing, also clear acrylic. We then did a buoyancy check on the heavy camera assembly. All hopes that it might turn out to be at least close to neutrally buoyant once in the water instantly disappeared. The thing sank like a brick. Oh well. Maybe a lighter bracket would help or a bigger housing, though it's big enough as it is.
We did a final check of our gear, made sure once again that the tanks' air valves were open, then held up the inflator and pushed the button to release air from our BCs to descend. I was surprised that there was none of the initial apprehension that I'd always felt on every dive before. I just went down, adjusted my buoyancy (I was loaded with a total of 12 pounds; a four on each front pocket and twos in the back) and began looking around. The sun shone through the cavern's small opening above and sent rays through the clear water. I saw other divers slowly appearing over the rocks, hovering in those rays and it looked just incredible. I snapped pictures of them just to find that the camera was still in above-water setting and the flash did nothing but illuminate scatter. I changed it to its proper underwater mode (the Olympus Stylus 770 SW has four - snapshot, macro, and two telephoto settings) and descended deeper. As I approached a depth of 30 feet, the camera beeped and flashed a red "depth warning" on its LCD screen. The 770 has a built-in manometer that shows depth in 1.5 foot increments. I later found that it only showed depths to 33 feet and no more.
I must admit that I had decided to take the camera deeper than its design limit of 33 feet even before the dive, wanting to see what it would do. That wasn't just reckless behavior and an attempt to see how much the camera could take before it flooded. I was confident Olympus had engineered it so there was a good safety margin and the depth limit didn't confine divers too much. So I took it deeper, all the while watching its display to make sure it was still okay. 40 feet, 45 feet and all was well. No bubbles, no flickering, no other sign of distres from the sleek little Olympus.
At this point we decided to explore some of the overhangs and venture a bit deeper under the rocks and into the nooks and crannies towards the bottom of the sink. We didn't get deeper than 40 feet last Fall, but this time I descended into a narrow cave-like descent that was indeed an overhead environment for some 30 feet or so. I had my handy magnesium LED flashlight with me. Carol motioned for my attention and reminded me to pull myself along the rocks as I had been shown before.
I never felt panicky or uneasy at all descending into the dark. At the bottom of the cave section I checked my dive computer and found, much to my delight, that we were at 51 feet. The Olympus seemed fine but when I tried to use the push button to toggle the camera into its scene selection mode to switch to the underwater macro setting it refused to do so. It also seemed like the 770 was all of a sudden in full 3X zoom mode. I took some pictures, then exited the cave section -- "cave section" is really an exaggeration; it's simply a brief overhead passage going down around the rock -- and began ascending a bit.
At about 40 feet I was able to change the camera settings again and then spent another 40 minutes or so exploring. We were shown some of the more interesting parts of the Den, including holes in the rock wall and also several sections that were either blocked off or had warning signs. I had often wondered if Devil's Den did not connect to a larger cave system as most sinks do, but I haven't found an answer yet though I asked several people. Carol, in the meantime was busy exploring the big Olympus Evolt setup and apparently had no problem at all with its size and negative buoyancy. I watched her exploring the camera and taking lots of pictures.
I marveled at all the large catfish swimming around. If any place should be called Catfish Hotel it should be Devil's Den. They are everywhere, majestically gliding around. And they are BIG. We saw "the Bus" again, the largest catfish I'd ever seen and wondered what they all eat. They are unafraid of divers, though they won't let you get close and don't generally pose for pictures.
We stayed down for almost an hour, until diving in the 70 degree water began feeling pretty cold. I wanted to go down again for one more lap around the debris cone at ten or 15 feet, but was immediately assaulted by a painful sinus headache, and so aborted the dive and came back up.
Out of the water I felt elated as I always do after dives. Walking up the steep stairs felt like nothing at all. The surface greeted us with bright sunlight and warmth, and I sat on a bench for 20 minutes or so, just basking in a wonderful feeling. My body felt great. It was a warm, satisfying glow. I felt very happy and contented. I contemplated how great diving was and how lucky I considered myself for having discovered it. Then I slowly made my way over to the park area where we had left our gear and got out of my wetsuit. The first dive of the new year had been great. We drove on to Crystal Springs to get ready for another Manatee tour early next morning.
Oh, I should mention one other thing I learned at Devil's Den. It marked the first time I tried using Optx magnifying lenses in my Scubapro Frameless mask. I need reading glasses above water but so far had gotten by without special optics in my scuba mask. Still, while the magnifying effect underwater made it a bit easier to read the dive computer, that was only the case in good lighting conditions. When it got murky I could barely see what was on my Uwatec's smallish display. Not good. So before the trip I had finally applied the lenses I'd gotten from the Hudson dive shop in Rancho Cordova when it still existed. I followed the instructions when installing the lenses, let them dry for 48 hours and they stayed in place when I first flooded the mask. I looked down at my dive computer and, wow, I could read everything! Unfortunately, I couldn't see anything else. Everything was blurry as if my mask had gotten fogged up.
It took me a while to figure the obvious: I had the lenses on too high, way too high. So high that I could barely peek over them. I later saw pictures that showed the semi-circles of the lenses sitting squarely on top of my eyes (see above). Not a good situation, and also not very photogenic. In the evening I pried them loose and repositioned them much lower. Unfortunately, this time they did not stick. I later found someone who used the same lenses and he said I should get "liquid glass" at Home Depot and glue them down that way. I'll try that. So for the rest of the trip it was back to squinting at the dive computer.
Manatees at Crystal River
Swimming with the Manatees had been a wonderful experience last Fall and I looked forward to seeing the large, graceful, gentle creatures again. That meant getting up at 5:15AM to get to the Pier at 6:15 sharp (which to my internal West Coast clock meant three hours earlier yet). A lot of people were already there, signing waivers at the Birds Underwater dive shop, listening to the do's and don't's of interacting with the Manatees and picking out their rental gear. We had our own, of course, and it was just a matter of changing into it. I inquired about the Nitrox class that I thought I might be able to take while there, but got a feeling that wasn't going to happen. And we learned a bit more about the tragic death of a middle-aged woman the day before. She'd been on a Manatee tour, but then collapsed and died. Apparently she had been quite large, had had diabetes, high blood pressure and some other ailments. A medical doctor had been onboard and the captain of that particular boat had been none other than Bill Oestreich himself, the owner of Birds Underwater and as experienced as rescue diver as they get. She'd been attended to almost instantly and had been brought to a medical facility in record time. It didn't matter.
Kris, our boat captain from last Fall, had the day off and was not around and so this time Rudy was our captain and tour guide. It was a beautiful morning as the boat slowly made its way onto the still waters. I'd been told Rudy knew the Williston area very well and he'd be the one to ask questions about Devil's Den. I did, and Rudy volunteered a few experiences and opinions.
For photography, once I took the two Olympus cameras along to hopefully get some good Manatee shots. We were treated to some wonderful scenery, with mist rising from the water for some awesome photo ops.
As for Manatees, this time the captain didn't spend time looking for them and their telltale bubbles but headed straight for the entrance to the Three Sisters spring system. They are more plentiful in the winter and tour operators know where they hang out. Outside the springs' entrance was a "Manatee Sanctuary," an area corded off with a floating rope. There were dozens in there, and a good number were roaming around outside. We got into the water and began snorkeling and admiring the Manatees. Last time I had seen them they'd all been eating, munching on sea grass and other greenery non-stop. This time, they were tired and spent most of their time sleeping, resting at the bottom with their peculiar looking snouts seemingly buried in the silt. Every few minutes they'd come up for a brief breath, sticking just the tops of their noses out of the water. They often took two such breaths, then sank back down and continued their motionless sleep.
We headed up the entry into Three Sisters where there were more Manatees. The water wasn't quite as clear as last time and so we experimented with the big Evolt whose huge glass lens in front of the 11-22mm wide angle lens (really 22-44mm in 35mm film terminology) has a very large diameter. We thought it'd be cool to position the camera so that part of the lens was above water and part below, for a special effect. That indeed yielded interesting shots and some equally interesting phenomena. For example, the width of the divider between the underwater and the above water world depended not only on the shutter speed, but also on the movement of the water. A bit of wave action made for a big "divider" whereas a still surface made for a much narrower and more interesting one. Nothing Photoshop couldn't fix.
Eventually we swam back out of the spring system and into the main arm of the river. As I exited I saw a congregation of Manatees and decided to take a closer look. I snorkeled over without ever looking up and took some nice shots of the magnificent creatures. Noone else was around, and there was a good reason. I had inadvertently entered the Manatee Sanctuary! How embarrassing. I don't know if it's possible to be red-faced in the water. If it is, I certainly was. The captain later told me he'd seen someone inside the sanctuary and hoped it wasn't one of his group. However, I was not the only transgressor. Up in the spring system we had encountered a videographer with an IMAX camera and two very bright lights that he kept training on the Manatees. That is in strict violation of the Manatee preservation rules and caused outrage on our boat. A photographer and videographer who was there to shoot on behalf of the Manatee habitat at the Cincinnati Zoo had recorded the violation and said he was going to alert the fish and wildlife department.
Drift diving Rainbow River
In the afternoon it was on to a lesson in drift diving. Drift diving is a special skill as it requires going with the current and letting yourself "drift" down a river or other body of water. Fighting the current makes no sense and is not the objective; catching it and drifting along with it, taking in the underwater scenery and just generally having a great time is.
We had filled our tanks at Birds Underwater and loaded our gear onto the tour boat that would take us up Rainbow River. The boat itself had to be towed there. Once at the starting point, a nice county park with the somewhat odd name of K.P. Hole, we donned our scuba gear and got on the boat. Captain Rudy explained the rules and scenery. Rainbow is a five mile stretch of river starting with a spring and ending where it enters Withlacoochee River. The springs are strong, making for a 3mph current, and so the water of the entire river body is turned over several times a day. This means the water is almost always totally clear and only gets murky from human intervention. Yes, a single diver can silt up the water pretty good, as I know all too well from my own early transgressions. Rudy explained that the grass at the bottom acts as a natural filter. He said we'd see brown clumps of dirt clinging to it; all the stuff the grass removes from the water. Disturbing the grass dislodges the dirt and silts up the water.
We arrived at the drop off point and split into a diver and a snorkeler group, with the snorkelers in charge of the dive flag. I was one of the first ones off the boat and found the current surprisingly strong. So strong, in fact, that I almost missed the dock at the river shore and had to pull myself up with my hands into the calmer area behind the dock where all the divers assembled. One of the snorkelers, a fairly large older woman, entered the water for what was to be her first such snorkeling experience. She seemed apprehensive from the start and had complained about the tight fit of the wetsuit, and then quickly panicked in the strong current. She made it back to the boat and held on to it, making for some scary moments. Captain Rudy calmed her down but she decided she was not up to it. A diver from our group suddenly found that she'd lost her weights. Fortunately for her, they were found.
Then we were ready to start the estimated two-hour drift dive downriver. Down we went and I almost immediately realized I had made a big mistake: I used a brand-new mask for the first time on a long dive in an unfamiliar environment. After the Manatee tour I had found the new ScubaPro Wide Vu mask and had fallen in love with it. It fit extraordinarily well and so I had bought it at Birds Underwater. As recommended, I had used toothpaste to get off the factory-applied coating of the inside surface of the lens. I thought I'd done a good job, but the mask fogged up immediately, despite liberal use of defogger. I used spit in a last ditch attempt to keep the mask from misting, but to no avail. So down I went into this unfamiliar dive spot and unfamiliar kind of diving.
Drift diving was totally different from what I expected. I thought I'd be able to essentially see the whole river from side to side and then gently and slowly drift downstream while enjoying the scenery. Instead, I found myself almost lost in a confusing, meandering landscape of tall sea grass meadows with winding channels running through them. The water was shallow and so you had to stay close to the bottom while trying not to touch the grass. I had a hard time seeing my fellow divers, let alone the entire width of the river. The current was fairly strong, but it wasn't the kind that simply carries you along. Instead, the water pulled me so I could never just hover, but without giving me a good sense of direction or any degree of stability. I almost immediately felt lost and struggled to maintain proper buoyancy and even basic stability. Sometimes I felt close to being flipped over. What made it worse was that I could barely see through the fogged lens of my mask. I even flooded and then cleared the mask a couple of times, but it almost immediately fogged up again. So in addition to feeling rather lost and uncomfortable, I couldn't see a thing and braced myself for a rather long two hours.
Another problem I had not anticipated was the constant ear equalizing in the ever-changing depth of the river which averages about five feet. So it's up to four feet, down again to 12, up to five, down again to ten, then perhaps fifteen and back up. And so on and so on. Each new descent required new equalizing and I found I didn't enjoy that very much at all. Eventually I managed to find a bit of a rhythm in making my way through the sea grass or following one of the paths through it, but I still could see almost nothing.
Turns out Carol had similar problems with her mask, also one she had purchased just hours before. It was a Scubapro Frameless, a mask that she was very familiar with (she wears noting but), but it still leaked on her as the silicone skirt had not gotten used to her face, or developed a "face memory" as she put it. Since this was my first drift dive she insisted we swap masks. I reluctantly agreed and wearing her Frameless made a huge difference. I could finally see and began enjoying the ever-changing scenery, never knowing what would be beyond a field of sea grass and stopping to examine one of the numerous "boiling" sand areas where spring water emerged from the river bottom. You had to hold onto something to stop, and so I didn't take many pictures. My colleagues on this dive also seemed to struggle and often surfaced to regroup. My new mask fogged up on Carol as much as it had on me, plus it was too big for her face and leaked. She ended up keeping it a quarter-filled with water that she kept swirling around to keep the fogging at bay. It was clearly not a pleasant experience for her and I think we both learned a lesson.
No matter how hard I tried to elegantly hover a foot above the bottom, never stirring up silt, always being perfectly neutrally buoyant, it was hard and I mostly failed miserably. I used my hands much too often. I held on to seagrass, grabbed for whatever rocks or roots or logs I could find, and groped at and into things I felt I perhaps shouldn't. I asked myself if newcomers shouldn't wear gloves when they go drift diving. The Olympus camera, without a protective case, dangled from the carry strap around my wrist, got dragged along the sand and rocks, and bumped into stuff so much I was afraid it'd be all scratched up. It didn't, but that's one of the drawbacks of not having a tough protective case.
I had wondered how I was supposed to do a two-hour dive on a little 65 cuft tank. Supposedly that was possible because of the shallow water and little exertion required. Well, for me the exertion wasn't that little and I gulped down quite a bit of air while trying to stay on even keel and going to where I wanted to go. So I nervously kept checking my air supply and quickly realized there was no way it was going to last me two hours.
I had hoped to see some exotic wildlife or at least a turtle or two, but there was little more than the usual variety of small fish. The sole exception was a menacing looking alligator gar, a big one, with his long mean-looking snout open. Those guys have a dual row of large teeth in the upper jaw and get as long as eight to twelve feet. This one looked like a particularly sinister Barracuda and he definitely wasn't small. I wanted to take a picture... just to find that my battery had gone dead.
Eventually I found myself quite a bit ahead of the group and decided to surface when I found a boat anchor line. It turned out to be our boat, waiting for us near the starting point. I was perhaps a hundred yards ahead and waited for the rest to arrive. Rudy pointed to the other side of the river and said this was where the small cavern was. So we dived over to take a look. As always, I approached it carefully, holding on to rocks and outcroppings. It was a small cavern, but I did go inside, after Carol, and looked around. That was the end of the drift dive. It had lasted about an hour and a half, and I was down to my last 300 pounds of air or so. I was both giddy with excitement and very tired when I got out of the water and walked back to the car.
Beneath Green Pond
The final dive of the trip took me back to Manatee Springs State Park and the Catfish Hotel sink. I am still not entirely sure why they call it that as I never saw a single sizeable catfish in there. Perhaps they are in the cave system. I wouldn't know.
After that 19-year-old had died in the sink a few days before, I wondered whether the park would institute new restrictions. At Birds Underwater I had talked to a man who worked at the shop and had been at Catfish Hotel the day of the accident. I learned that it hadn't been three kids, but the one kid from Texas and then a dive master and a scuba instructor from a local dive shop not far from Crystal River. The kid had been affiliated with the dive shop and so maybe they were showing him around the local dive places. Somehow the two experienced divers ascended when they couldn't see their young buddy, assuming he'd already gone up. He hadn't. One of them went back down and entered the downstream cave system where he found the young diver, apparently wedged in somewhere, already dead. He could not get him loose and so went back up. When the body was recovered it appeared he had bumped into something hard, incurred substantial injuries, and had perhaps gotten knocked out. The sheriff was screaming at the experienced divers for letting that happen.
We got to the park somewhat late and found nothing changed. No new signs or restrictions, no mention at the ranger's station at the entrance of the park where you sign up, pay the US$10.50 fee for diving, and hand in your scuba certification card. This time we weren't alone. Several teams were diving, and not just open water divers.
We drove to the parking lot and walked over to check out the situation at sink. It was as green as last Fall, totally covered with duckweed. Duckweed is the smallest flowering plant in existence and it grows in still or slowly moving water. It's not slimy but it can sure take over. The vegetation around the sink apparently had dropped some foliage and so the sink itself somehow seemed smaller although the water level was the same. Several divers were floating by or off the entry platform. We talked to some and it quickly become obvious they were cave divers, and experienced ones at that. They wore their doubles, had stage bottles, and each had not one but two scooters. I can't remember all they'd said but apparently they'd gone in almost all the way to the end of the 10,000 feet cave system. One of them wondered how Sheck Exley had ever made it that far just swimming against the current.
We went back to the car to don our gear and passed other divers. One group returned to their truck that was parked next to us as we geared up. Once again the wetsuit practically just slid on and I was amazed (and thankful) at the huge difference a bit of humidity can make. I checked the two cameras I was going to take diving - a Casio EX-Z700 in a clear acrylic deepwater housing and, once again, the Olympus 770 SW - and then we walked back to the sink. I was first to get into the green duckweed that quickly covered everything. We took pictures of ourselves floating in duckweed, wondered how the cameras were going to handle THAT challenge, felt a bit guilty for taking the expensive Olympus Evolt setup into the mess, and worried about visibility with all those divers. I put my head underwater to take a look around and it indeed seemed darker and nowhere near as clear as last Fall when we had he sink totally to ourselves. I feared it'd be essentially a no-viz dive and that wasn't a pleasant thought.
We signaled each other and went down, with me again feeling no apprehension at all. It became immediately clear that the water was still plenty clear enough to provide a view of the entire sink in all its majesty. I lowered myself a bit to assess the situation and adjust my buoyancy. My dive buddy motioned to me and pointed behind me. Ouch. Clouds of sand and silt. Apparently I had kicked up a good bunch of silt while getting buoyancy right. I mentally slapped myself.
Then we headed for the deeper end and the dark outline of the cavern entrance. This was going to be another challenge for the Olympus. It had already handled over 50 feet at Devil's Den, but the Catfish sink was deeper yet. I approached the sloping entrance to the cavern cautiously, as usual. I clung to the bottom, always made sure I had something to hold onto, and lowered myself foot by foot beneath the dark overhang above us. Depth 63 feet. At that moment, I admit, the only thing on my mind was breaking my old "record" of 65 feet and so I improvised hand signals to my buddy indicating I wanted to go three feet deeper. She'd already motioned to go back up but then gave me the OK sign. So I carefully lowered myself another few feet and now my dive computer showed 67 feet. Somehow I was elated at that and would have gone down a bit deeper yet had my buddy not stopped her descent and started working with the big Evolt.
I laid there looking up, seeing the greenish light past the pitch-black overhang of the cavern entrance, studied the logs in the water and couldn't get enough of the view.
Then I turned my attention to my cameras and began taking pictures. It quickly became evident that the Casio, set to its sole underwater mode, used the flash no matter what and so, despite the snap-on diffuser plate in front of its internal flash, it simply lit up scatter. The Olympus, at more than twice its rated depth, was still alive, but once again it was impossible to select modes and the camera was in full telephoto mode though I hadn't extended the zoom. I studied the buttons and noticed that some seemed fully depressed. The mode button, especially, was pushed in all the way from the water pressure. I took some shots, not knowing what to expect, then alerted my buddy to the phenomenon. Though this time we both wore masks that worked for us (I had my trusted ScubaPro Frameless, she had her new Frameless that apparently now memorized her face) she looked uneasier than I remembered ever having seen her underwater and so we slowly began to ascend. There was much to see and do and we began exploring the scenery and taking pictures. As usual, the Olympus controls returned to normal operation at around 40 feet. We took close-ups of the cameras underwater, with their LCDs displaying what they saw.
On the other side of the sink, opposite of the main cavern, I noticed another, smaller cavern and swam to it to investigate. It was a dark hole and I wondered it that was the entrance to the upstream cave. That would have meant water rushing out of it and thus safety, but I decided to be extra careful and only peeked in a bit. Carol did not follow and I took that as a sign not to venture farther. I then laid on a ledge just watching the cavern. Then took some macro shots and found a few holes in the vertical limestone wall. I peeked into some and again wished I'd have a light but also understood why the park insisted on open water divers not taking one down. One of the reasons why I took it easy was that I had such a great time. The other was that I wanted to make this a one-hour-plus dive. As usual I tried to conserve air, but my little 65 cuft tank soon got dangerously low. I finally emerged after 65 minutes with less than 200 psi of pressure left.
Duckweed made the exit a riot. It was simply everywhere. So while basking in the usual mix of slight headache and afterglow we played with the stuff, took pictures and I took a bunch of breaths from Carol's Nitrox tank that still had 1200 psi in it. Though it had twice the oxygen I didn't really feel a difference, but also didn't expect to after just a half dozen breaths.
Eventually we walked up the wooden stairs and used the makeshift shower and hose to rid ourselves of as much duckweed as we could. That was no easy task as it not only gets EVERYWHERE, but also can't easily be washed off. Apparently the best way is to wash off what you can, and then wait until the rest is dry when it becomes easy to blow it off.
On the way back Carol confided she'd been cold almost right off the bat in her 3mm wetsuit and also had been very conscious of the depth limit for the 42% oxygen she had in her Nitrox tank. There are calculations that determine how deep you can go without exceeding a given maximum partial oxygen pressure, the level where oxygen toxicity might become an issue and, in a worst case scenario, lead to convulsions. The generally accepted safe number is 1.4, or a PPO2 of 1.4 - Partial Pressure Oxygen. In her case the depth limit was something like 79 feet, so we'd only gotten to ten feet of it, but she's so experienced that I felt she'd have her reasons for not wanting to go deeper.
It was getting close to five PM which was the time we had to collect our C-Cards from the Ranger Station. We got there a few minutes after and saw on the white board that two or three dive groups had still not returned. I asked the ranger if she breathed a sigh of relief every time a group came back to collect their cards and she said yes.
Later, over dinner, we all discussed our experiences. For me it was yet another instance of not encountering the expected and instead run into other issues. Given that the diving accident had preoccupied me ever since I' read about it, that I had written and talked about it, it really wasn't on my mind when we got there. Once again, I didn't feel the least bit of apprehension going down. When laying at the bottom as deep into the cavern as I dared to go, I marveled at the views and the light and putzed with the cameras. Before the dive I had been anticipating finding the exact spot where Sheck Exley had taken his picture, printed in "Caverns Measureless to Man" and duplicating it. Yet, Sheck barely entered my mind while I was down there. Even more amazingly, the fatal accident didn't either. The cavern didn't feel any more menacing, nor was I afraid. I had my usual healthy respect, but nothing more. I did not peek into the black below me and wonder what had happened to the young diver and what his last moments had been like. I did change my views on being able to get separated in the sink. If visibility is poor and one ventures into the cavern area, it's possible to lose sight of one another. But in order for that to happen, you do have to go deeper into the dark than is advisable, especially without a light.
Turns out it had been different for others. Some knew about the accident, some did not. Most seemed to simply take it as an unfortunate accident, like the death of the lady who'd died after the Manatee snorkel tour. It had been different for Carol. She told me later how she'd felt apprehension and a shiver down there near the cavern entrance, and it had not only been the cold or the fear of the approaching Nitrox depth limit. She related how divers in trouble often start doing irrational things as the situation becomes desperate. Scratch at things, drop equipment, rip off their masks or regulators. She had eerie feelings and she did not want to find some telltale mark or piece of equipment left by the young man who had died close to there just days before. A young man that had gone from the thrill of getting his Adventure Dive card to losing his life in a sink in northern Florida. I guess it's all part of it.
So there. My first dives of 2007. Every minute underwater was worth it. I thrilled in it. I screamed and laughed with joy whenever I surfaced. The equipment seemed to weigh less. My wetsuit went on easy and I never had the problem with the sides of my fingernails digging into the soft skin of my fingertips until they became infected as they had last Fall. My back, which had been acting up some before the trip, never once hurt as I feared might happen with all the heavy equipment. Not once. I'd learned to drift dive. I ran into silly new-diver mistakes and committed them all to memory so I would not make them again. I forgot only one thing, my dive log. Not a big deal as bad as my Uwatec Smart Z dive computer logs and memorizes all of my dives. I had fun and ample time with reviewing all those cameras underwater. I got to listen to other divers and exchange stories. I found I was no longer afraid right before going under. And that I enjoy scuba tremendously.
I want to go back right now.
February 20, 2007
Another trip: testing cameras and some bad news
Tomorrow I'll be going on the first dive trip this year. Northern Florida again, visiting some of the same places I did my NAUI Advanced Diver classes and certification dives in last Fall. There will be some more training, but the primary purpose is to give four more underwater cameras a serious workout. I really look forward to this as the cameras are so different. They essentially cover the whole range from the bare minimum to innovative technology to a serious underwater rig. Each will appeal to a different potential user, and it should be interesting to see how they perform.
We'll be testing Casio's ultra-slim 5-megapixel S500, the more utilitarian Casio Z700, the brand-new Olympus 770 SW, and the Olympus Evolt digital SLR. Each has an interesting aspect. The tiny, sexy S500 doesn't even have an underwater shooting mode and it's definitely not a camera that looks like it should ever see water, but a deepwater case is available for it and so we'll see what the little thing can do. The Casio Z700 does have an underwater mode. It's a very capable 7.1 megapixel camera for which you can also get a deepwater case. So this is an example of a setup that would appeal to many tourists and recreational divers. It's small and handy, yet quite powerful, AND you can go diving with it. The third camera is nothing less than stunning. I was already impressed with the Olympus 720 SW 7.1 megapixel camera that was waterproof down to ten feet (we also tested it with its optional deepwater housing). Well, Olympus now released its successor, the 770 SW, and it can handle depths of 33 feet without housing! The final camera in the foursome, the Olympus Evolt 330 digital SLR, is an entirely different beast. It's a competent, economical single lens reflex camera with a live view LCD and an external flash. Put the camera and the flash into their respective housings, link them with the frames and brackets, and you have one huge humdinger of a rig. I can't wait to see how it handles underwater and what sort of pictures it will take.
I also came across something I didn't necessarily need to see the day before this trip. A young Texan diver died at Catfish Sink at Manatee Springs State Park, the very place I'll be going to again. The February 20, 2007 report at gainesville.com indicates that the 19-year-old got separated from his dive buddies, ran out of air, and likely drowned. His name was Bobby Rothel and he had a recent PADI Adventure Diver certification. A representative from the Sheriff's office said the three were not cave diving, "but they were diving in an area that would fall under the category of cavern diving -- where an overhead obstruction does not allow direct access to the surface." Now I've been down there. The water is crystal clear and the only way you can get separated and trapped is if you leave the sink and enter the Manatee Cave System that goes both upstream and downstream from the sink. You can't see the cave entrances either; they are to the left and right of a cavern overhang where it gets dark. Since the spring current is pretty strong it's advisable to stay clear of the syphon that can potentially suck you into the downstream cave. In order to prevent divers from venturing too far into the cavern/overhang, the park strictly forbids open water divers from taking lights with them. That would be too big of a temptation.
So what can happen? A diver without cave or cavern training and without the proper respect for potentially dangerous situations might decide to go poke around a bit deeper into the overhang. It's then pretty easy to get grabbed and swept away by the current. Without a light you'd then find yourself in pitchblack water. Panic sets in and the diver might struggle to swim against the current, thus exerting him/herself and quickly using up the air supply. Even if someone remains calm, negotiating the fairly short 500-foot cave to the basin on the other side could be deadly without light. It's not just a tube; sometimes, despite the current, you may have to grope and find the proper passage. If you don't, panic might set in and you're done. Experienced cave divers and instructors shudder at the thought of losing beginners and untrained divers that way. They know the proper procedure (don't exert yourself swimming, go to the bottom or side, grab hold of rocks and outcroppings, and pull yourself out). As is, I am glad Catfish Sink remains open, though I am sure park management at times wonder whether it's better to clearly alert to the danger or simply keep open water divers from taking lights. One could argue that a light represents a good safety device in case something happens, but the risk of it being abused for unwise exploration is likely greater.
February 10, 2007
Some things you'd rather not know
Well, I finished a review of the late Sheck Exley's "Caverns Measureless to Man" and posted it on the site. I also informed the publisher at cavebooks.com and he was nice enough to send me a complimentary email and alert me to another must-read cave diving book, "The Darkness Beckons" by Martyn Farr. I ordered it and anticipate its arrival with great interest.
One of the things that puzzled me about Sheck Exley's story was that he never used a rebreather, or at least he never mentions one in "Caverns." Exley frequently commented on scuba bubbles dislodging debris from the cave ceiling, reducing visibility. Low viz is never pleasant, and can be life-threatening in a cave. So I wondered why Exley apparently never used a semi-closed circuit rebreather that generates far fewer bubbles, greatly reduces the amoung of gas required, provides warm and moist breathing gas, and has other benefits that reduce decompression time. I am aware that while rebreather technology has been around for well over a hundred years, they've only become commercially available (and feasible) relatively recently. However, semi-closed rebreathers had been used in cave diving as early as 1956 and 57 at the Wookey Hole Caves in Britain, and in the early 1980 they were employed in extensive and heavy-duty cave diving in France, Mexico and the US. So I began searching the web for examples where rebreathers were used in cave diving and exploration. And quickly found a stunning example.
Deepcave.com is the website of David Shaw, an Australian living in Hongkong. He was born in 1955, is a pilot and was introduced to diving by his son and was immediately hooked. They did some wreck diving, then Shaw completed a cave diving course in Florida at Cave Excursions in Live Oak, FL, and became engrossed in the thrill of it. As his explorations became more elaborate he decided to use rebreathers. He got an Inspiration unit, but soon found it couldn't handle the increasing depths he explored. So he switched to a US Navy-developed Mk15.5 and modified it for his purposes, replacing analog with digital electronics and so on. Like other cave diving enthusiasts, Shaw's primary interest was exploring what had never been explored before, but found that this took him to ever greater depths.
Shaw's site then has a section on "recent dives," those including two at Boesmansgat in South Africa in 2004. In June he went down to 718 feet. That dive is explained in a 14 page report with 30 color pictures and even a dive computer profile that is downloadable as a PDF file. Shaw described the preparations for the trip, the trip, his equipment, the modifications he had performed on it, and the dive itself in an easy, conversational style. The many pictures make the story come to life. Yes, sometimes a picture says a thousand words. Shaw describes how they found Sheck Exley's line from ten years before, 1994, during some preliminary dives. He describes how he used a program called Z-planner to compute various alternates with varying safety factors to be used with his two VR3 dive computers. He also described the setup of his rebreather that included two three liter tanks, one with air for his wing and the other with argon for his DUI dry suit. Then he had two three liter spheres, one with air and the other with oxygen -- good for a ten hour maximum. That's all he had on him. [see complete equipment list and modifications]
So then he goes on this deep dive, calmly wondering if all the equipment would stand up to the great depth. Nothing failed, however, but at about 700 feet, after a ten minute decent, Shaw experienced tunnel vision which he interpreted as the start of HPNS (High Pressure Nervous System) syndrome. He stopped and looked at the vast expanse of very clear water, commenting that breathing with his Mk15.5 rebreather was as easy as it was at 20 feet and marveled at the performance of the device. His VR3 computer then gave him all the decompression stops and he describes how he used all the tanks with different gas mixes. He also describes the technique on how to eat and drink which he did while using a reguator rather than his rebreather. He went into other practical aspects, like urinating through a valve in the drysuit. Total dive time with all the decompression stops was 517 minutes. Shaw mentioned the very low gas consumption -- barely more than a tenth of the gas used in a 1996 open-circuit scuba dive in the same location -- as one of the great advantages of the rebreather. Though this was a record depth drive with a rebreather, Shaw reported no fatigue. In fact, they did some dry cave exploring the next day, then a scooter dive at about 260 feet the day after that. Just a pleasant trip, no big deal.
Four months later, Dave Shaw returned to Boesmansgat for another world record dive (link to PDF). He explains how his digital electronics were filled with medical grade paraffin to prevent implosion at great depths. And how this time he used oxygen instead of air for the suit inflation tank, so as to have an oxygen backup. He hadn't been sure how deep bottom was and that made planning more difficult, and also presented the danger of either shooting past the line, or getting stuck in the muck if the line was too long. This time he used the dive computers just for bottom timing and carried his plans for various depths on slates. Why various plans? Because each second at a depth of over 900 feet means an extra 70 seconds of decompression.
Shaw encountered no problems whatsoever. He arrived at the bottom at 885 feet and it was nice and rocky. One of his VR3s failed but he began swimming around, saying "I was relaxed and could almost not believe where I was." Well, that was when he found a body, that of another diver by the name of Deon Dreyer, a 20-yeard-old who had died there 10 months before, on December 17, 1994. "There was no shock on my part, but rather a decision making process of what to do," goes Shaw. It was easy for him -- try to recover the body. Unfortunately, Deon's big doubles were stuck in the mud and Shaw could not dislodge him. So he did the next best thing, tie a line to the body so it could be found later. The ascent and decompression was uneventful and the whole dive lasted nine hours and 40 minutes. A body recovery was then planned for January of 1995.
So I move to the "Future Plans" section of Dave Shaw's website. There he explains the scheduled body recovery, what mixtures he'll use and how many tanks. Once again he'll have his four small on-board tanks, then a total of 19 bailout tanks in case the rebreather failed, with seven different gas mixes, with the bailouts starting to be used at 500 feet. He praises the Scubapro X650 second stage that "breathes brilliantly at great depth." He goes on to the support divers and their roles. The report completes with "More to come as I get time....." But no report.
Well, at least I had my answer. Apparently rebreathers are a workable solution for this sort of diving, one with many advantages. I contemplated that, studied the equipment list and modifications with great interest, and wondered whether Sheck Exley would eventually have started using rebreathers had he lived.
But now I wondered how the body recovery project had gone and I poked around some more and found the report at the Technical Diving Africa website. To my great dismay, not far into the page I found this statement: "This page is dedicated to David Shaw who in the attempt to retrieve Deon Dreyer lost his own life at Boesmansgat in Southern Africa."
That really hit me hard. This had seemed like such a success story. A man in his 50s calmly doing all this incredible diving, the use of the rebreathers, the total lack of any real problems. And now he apparently had died as well. What had happened?
Once again, the entire operation is described and illustrated in detail, the plan covering everything from "D-Day" minus 9 to D-day plus 2. Dave Shaw was to be the leader, doing the body recovery. Don Shirley, his backup, was going to 700+ feet in case Shaw needed help.
Then the description of the dive. Shaw goes down at 6AM, a Sony vidcam mounted on a helmet to record the recovery. Shirley follows 13 minutes later to meet him at 220 meters. Shirley sees Shaw's light, but no bubbles indicating purging during ascent and no movement. He prepares to go down, but his rebreather's Hammerhead controller implodes, likely the result of losing a bit of oil during a repair the night before. Now he's on manual rebreather control and there's no way he can go deeper. Other support divers meet Shirley 43 minutes after Shaw had begun his dive. "David not coming back," writes Shirly on a slate. Two and a half hours into the decompression Don Shirley starts feeling awful and fights for his life, feeling vertigo and throwing up -- the result of an expanding helium bubble in his inner ear. Yet, he makes it through an almost 13 hour decompression and is placed into a recompression chamber. He recovers, but it takes a long while.
Amazingly, both dead divers were recovered as well. And the Sony camera had worked, showing what had happened. Apparently the recovery had been more difficult than David Shaw expected as the body, instead of being skeletal after all those years, was in an unexpectedly buoyant condition. He is working harder than he should, building up CO2 and incurring increasing narcosis. He is alert enough to abort, but then his free-floating dive light, which he couldn't put around his neck due to the unusual vidcam helmet, gets snagged in the line tied to the dead diver. The now exhausted Shaw tries to untangle it, but can't. That was all it took.
To me, apart from being sad to find another inspiring story end in tragedy, it reaffirms a basic truth: anytime you make an exception for anything or anyone, things tend to get fouled up.
Unbelievably, you can see the entire last dive on YouTube here.
February 09, 2007
Pretty much ever since I took up scuba, I've been thinking of how safe it is. It's not a primary consideration, but the thought pops up and I never know when. My then ten-year-old son was quite concerned when he learned I was going to dive at Devil's Den, though I am sure it was the "devil" part that scared him and not so much the diving. The diving certification organizations, and particularly PADI, go out of their way to paint scuba diving as a perfectly safe, relaxing, and wonderful experience. Many diving books point out the exemplarily low incidence of diving accidents and deaths and compare it to numerous other activities with much higher accident rates. Even fairly scientific diving literature likes to point at diving safety and pull up numbers showing that the percentage of divers who contract the dreaded bends, decompression sickness, is extremely small. And when you look at the numbers, the sport of scuba diving indeed looks safe.
I think I read somewhere that most accidents occur in the bathroom of one's own home, but they are usually not fatal. The number of people killed in automobile accidents each year, on the other hand, is staggering, almost 50,000 every year, making up for almost half of all accidental deaths. Flying would seem to be more dangerous, but the chance of dying in an airplane crash is infinitely smaller, something like 200 a year. Unfortunately, that number is uncomfortably close to the roughly 150 people who die every year in the US from/while diving. But what does this really mean? The rate is about five deaths per million dives. So the chance is one in every 200,000 dives. Even Chuck, my PADI dive instructor with his 11,000 dives would have to go through almost 20 lifetimes of such diving until, statistically, his number is up. Last I checked, Chuck was fine. On the other hand, in February of 2007, state officials in California suspended the operations of an elite dive team after two very experienced divers with high quality equipment died during what should have been routine maintenance in the California aqueducts.
When scubadivinginfo.com was started, I set up Google alerts to send me emails with diving news, using the keyword "scuba." I have been getting them ever since, and a disconcerting number are about diving accidents from all over the world. In the beginning I occasionally reported on some of them in the news section of the website. This resulted in a bit of criticism from some who felt a scuba site should be all positive, and not point out the dark side. I thought about that for a long time. I did not want for scubadiverinfo.com to simply be a diving cheerleading site. If there are dangers, I wanted to point those out as well. In the end we decided to drop most accident reports. Not because I felt they were downers and needed to be withheld from site visitors, but because diving accidents seem to generate far more publicity than other "more common" deaths. As a result, virtually every scuba accident is reported whereas casualties in other areas of life are much less prominently featured. So putting up a news item every time I get a Google report would indeed distort things and paint a gloomy picture. Hey, statistically diving is much safer than skiing or riding a snow mobile. Yet, you rarely ever read chiding reports of skiing or snowmobile fatalities.
Maybe thinking of diving safety is simply in the nature of the sport. Almost anywhere else you can bail when things get hairy. That's not an option when you're 100 feet underwater. If you run out of air, things get desperate rather quickly. Sure, we all learn various ways to handle out-of-air situations, from "controlled ascents" to using secondary air sources from a buddy's system to buddy breathing and so on. But that assumes a diver won't panic and bolt for the surface, which in itself can have nasty consequences. Air embolisms, and all sorts of other decompression illnesses. There's just so much that can go wrong. And when it does, you're in an environment essentially foreign to man. Sure, we all begin life in a womb, in liquid, but after that we're surface dwellers and submerging means entering a hostile world.
Then there are all the various things that can go wrong. Underwater almost anything can become toxic. Life-giving oxygen? We need it, but too little and you pass out and drown. Too much and there's the danger of oxygen toxicity that leads to convulsions, and you drown. Nitrogen? An inert gas, but one that not only seeps into your system and tissues as you go deeper and thus must be carefully expelled again as you go back to the surface, but also one that becomes narcotic at depth. Nitrogen narcosis has been romantically described as "rapture of the deep" and some divers have even written about enjoying it, but it can become deadly. The minute traces of carbon monoxide in the air that hardly ever harm us on the surface? Well, increased pressure underwater means carbon monoxide partial concentration can become deadly. Carbon dioxide? That's what makes us know when we need to breathe. Get that out of whack and you can simply pass out from a lack of oxygen and drown. Not a nice picture. And that's not even going into all that can happen when you go technical and start using alternate gas mixtures.
And there's more. I generally view every sports as inherently healthy. Engaging in outdoor recreational activity means exercise, fresh air, movement, the works. Yet, the more I read, the more it seems that diving really isn't the best thing for one's health. Divers often report unusual fatigue. Those engaging in extreme diving may take days or weeks to recover from a single deep dive. Carol reports that using nitrox helps her emerge from dives much fresher and feeling much better. Yet, I've also come across rather disconcerting studies that seem to indicate that the higher partial pressure of oxygen during a dive is inherently bad for the human cardiovascular system, deteriorating its protective cell linings and resulting in other temporary and permanent damage.
I won't let any of that stop me. I intend to follow all the rules, plan my dives, never do anything stupid, and never dive beyond my training. Yet, as a curious soul I have also come across the dangers. Maybe that is just inevitable. One of the things I often think about is how no one is ever more than a few words away from absolute and total disaster, every day. Yell "fire" in a crowded theater. Or "bomb" in an airplane or airport. Tell your boss to kiss off, a teller that you're holding up the bank, or threaten a police officer. Or say certain things to a spouse, friend or relative. Life as you knew it is over in an instant. Things are simply dangerous, so why should it be any different with diving?
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.