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True Story by: Richard Pyle / deepreef@bishop.bishop.hawaii.org
DescriptionHere's a story from Richard Pyle (deepreef@bishop.bishop.hawaii.org) of a recent dive trip that nearly cost him his life (again).
Confessions of a Mortal Diver II by Richard L. Pyle Some Background On Thursday, September 24th of this year (1998), I joined some friends of mineaboard a sailboat cruise to Necker Island, a tiny remote island severalhundred nautical miles from the nearest civilization. We were on a 9-dayexpedition, which consisted of a three-day voyage to get there, three daysof diving while there, and a three-day trip back home. I had my rebreatherwith me, and we had several objectives, but my primary objective was tocompare the fish assemblages there with the assemblages found at the mainHawaiian Islands, and my real motivation was just to have good fun with goodfriends. We weren't certain what sort of diving habitats we wouldencounter, so I came prepared with the full set of equipment to do deepmixed-gas dives, but had no specific plans to do any such dives ifcircumstances didn't call for it. Several others on the trip were diversalso, but all planned to use only regular air scuba gear on mostlyno-decompression or mild decompression dives.
The three days to get to the destination were benign and pleasant. Theweather was very favorable, and we were travelling down wind. The vesselwas a 70-foot sailboat equipped with a compressor and other amenities fordiving. We stopped at a couple of places on the way to look for some tinypinnacles that came from 2400 feet up to within 60 feet of the surface.Unfortunately, they were not where the charts said they should be, and wedidn't have time to spend looking for them in great detail, so we continuedon our course. We arrived mid-morning on Sunday, September 27th. Our first anchorage wasabout 100 yards on the lee side of the tiny island, on a small sloping ledgethat ran from 60 to 80 feet. The water was crystal clear, and the fish lifewas (were?) utterly AMAZING. It was an absolute spear-fisher's wet dream.More gray snapper ("Uku") and large jacks than I have seen anywhere in thehuman-inhabited Hawaiian waters - even better than Midway Atoll. Of course,there were also lots and lots of sharks. Mostly White-tip reef sharks, Grayreef sharks, and Galapagos sharks. I was actually amazed not only with theabundance of sharks (again, even more than what I've seen at places likeMidway), but how close they would come. They were not in anywayaggressive - I think it was mostly the fact that I was on a rebreather thatallowed me to approach so closely. For the afternoon dive on Sunday, we motored out to the edge of the shelf.The island is surrounded by an almost perfectly-flat shelf ten miles inradius around the tiny rocky island (which itself is less than a mile longand a couple hundred yards wide). Along the perimeter of this shelf is afabulous ledge about 90 feet on the top, and about 110-120 feet on thebottom, sloping down in some places to about 150-160 feet. Within a stone'sthrow of this ledge is an extremely precipitous drop-off to a thousandfathoms (6000 feet) or more. I spent about 90 minutes on the ledge with aPO2 setpoint of 1.4 or so, and saw all kinds of fish and many, many sharks.Out at this ledge, the most common shark species was the Galapagos, but afew of the other two species were also around. Again, throughout the divethey were extremely benign. There were usually about 5-7 Galapagos sharksin view at any given time, ranging in size from about 4 feet to about 6 feetin length. Anyone who has spent a lot of time diving with sharks will know that thereis a "comfort zone" at which the sharks stay, that is usually about 8-12feet away from a diver. Galapagos sharks tend to have a narrower comfortzone - usually more like 5-8 feet (as anyone who has dived at Midway willknow). On this dive, however, the Galapagos had a comfort zone with me ofabout 2-3 feet. They were LITERALLY swimming right in front of me, and onmany, many occasions I could have just reached up and petted them as theyswam by. I figured the extreme proximity was mostly due to the fact that Iwas diving with a rebreather. Although slightly disconcerting, theomnipresent sharks showed no aggressive tendencies, even when I collectedfish specimens, so despite being alone on the dive (the scuba divers hadalready used up their precious bottom time early on), I wasn't terriblyconcerned. I ended the dive just before sunset, owing only a few minutes ofdeco. As I came up the decompression line attached to the boat, the sharksfollowed me up, but I wasn't concerned about them very much because they hadbeen so benign the whole dive. All of a sudden, however, one of them (thelargest) charged at me - not terribly fast, but fast enough to startle me.I was forced to physically kick it off as it approached. It seemed barelydeterred by my foot in its face, and just then another one took a charge.For the next 5 minutes or so, the 7 or 8 sharks surrounding me (all within a10-foot radius) started acting more and more agitated and taking turns atcharges. On several passes I had to physically kick them off. I clipped mycatch bucket with my specimens in it to the deco line, then moved upshallower. This split the sharks between me and the bucket. They werecoming up to the bucket and nuzzling it, then coming up at me for a pass.It was terribly unnerving, especially given the fact that the sun wassetting, and I was all by myself in the water. When I only owed about 3 or4 more minutes of deco according to my computer, I decided to call the dive.I made this decision based on the fact that the computer I use has provenextremely reliable for not getting me bent under a wide range of divingconditions, and the sharks were becoming increasingly unnerving. Back inthe boat, I breathed pure oxygen for a few minutes just as a precaution, andwhile still a bit shaken by the shark activity, I was physically feelingwonderful. We tried another similar ledge the next day (Monday), and had a whole day'sworth of enjoyable, but otherwise uneventful dives...that is, until the lastdive of the day. On that dive, I set out on my own for another 90-minutesolo swim starting at 150 feet and working back up to 80 feet or so. Thedive was absolutely magnificent! So peaceful on the rebreather, with noother divers around. It was one of those dives that reminds me why I trulyenjoy diving in the first place. It was a real "feel happy" sort of dive.I had swam a very large circuit - maybe a quarter mile or so, finding allsorts of interesting ledges, overhangs, tunnels, etc. I ended up back atthe anchor to the boat. As you might well imagine, the anchor on a 70-footsail boat is a pretty large chunk of metal (several hundred pounds), andthis one was connected to the boat by a giant chain which probably weighedclose to a ton over its entire length. During the course of my dive, thecurrent had picked up considerably, as had the wind and the chop at thesurface. The anchor was wedged deeply under a ledge at 90 feet, so I knewwe would have trouble pulling it up, but I figured I'd leave that problemfor the boat captain to worry about. I swam up the anchor chain to thedecompression line, and was just about to clip off the bucket with my fishspecimens in it, when BANG! - it sounded like a gun-shot went off. Ilooked up to see this near ton of chain sinking rapidly to the bottom, andthe boat drifting off. The chain had snapped near the bow of the boat. Atthat point, I had a split-second decision to make.....stay with the boat, ormark the spot where the anchor was. If I stayed with the boat, I'd probablyhave to break decompression and sit on the boat while we sorted thesituation out. Thus, I clipped the fish bucket off to the deco line(attached to the boat), then bolted for the bottom. I deployed my sausagewith my up-line reel, and tied the reel to a coral head. I then came backup the line and did most of my required decompression. The boat crew hadinstantly known what had happened, saw my float, and figured out what I haddone. It was getting late in the day, and there was less than an hour of daylightleft. If we were to recover the anchor that day, we'd need to act quickly -so rather than do extra safety deco, I surfaced and got back in the boat.Knowing that I would be the one to go recover the anchor, I left therebreather on my back, stayed in full gear, and continued to breathe pureoxygen. We quickly discussed our options, and developed a plan whereby Iwould first go back and find the anchor, then a free-diver would watch meand convey signals to the boat. The boat would come directly over me anddrop a 2-inch rope with a shackle at the end of it. 50 feet up the rope,there would be 40 lbs. of lead strapped on. The idea would be for the boatto drop the line with the lead near the anchor, and hold position. Thatwould give me 50 feet of slack rope to work with on the anchor. When therope was properly attached to the anchor, I'd give the signal to the freediver to tell the boat crew to hoist away. The first part went as planned. I found the anchor, signaled to thefree-diver, and the free diver directed the boat. The boat dropped theline, but it apparently got hung up on deck somewhere, and in the fewseconds it took to free it, the boat drifted off a bit in the wind, current,and chop. The 40 lbs. of lead landed about 80 feet from the anchor, so Ipulled like hell on the slack end of the line to make up the 30 remainingfeet to the anchor. For about 10 solid minutes I worked harder than I everhave worked before underwater, trying to drag that 2-inch line with a 40-lbweight across a rocky bottom, while the other end of the 300-foot ropearched through 90 feet of water to a 70-foot boat. I got it *almost* allthe way there, but couldn't get the last 5 feet because the boat wasstarting to drift off again. I signaled to the free-diver for more slack.Unfortunately, I didn't realize that, through 90 feet of water, in thefading sunlight, the free-diver could barely see me. He thought I wasgiving the signal to hoist away. Once the boat started pulling in the line,I had no choice but to let the line go. I knew it would be a while for the boat to get the line up, realize theproblem, then get into position again. I took the time to catch my breathand relax, make sure the rebreather was still working correctly (it was),and assess the situation. There were a few Galapagos sharks around, butnone seemed too aggressive. Looking at the anchor, I realized that I could"walk" it out from under a ledge, down a slope, and clear it from theoverhang. That would make recovery a LOT easier, so with a great deal ofeffort, I got the anchor down the slope and free of the ledge. Thisrequired first gathering up about fifteen feet of slack chain, which wasvery heavy. In any case, I spent the time with a fairly heavy workload.Eventually the boat came back for a second drop of the line. This would beour last attempt. It was getting so dark that the free diver couldn't see meany more. I slowly came to the surface (breaking a few minutes deco) totell the boat where the anchor was - then dropped back down to the bottom.This time the rope landed near the anchor, and I only had to drag it about10 feet (very heavy workload again), after which I quickly shackled it up tothe anchor. I came up to start doing deco at 30 feet or so, and signaledthe free diver to tell the boat to hoist away. Not wanting to be anywherenear that chain as it came up, I drifted back to find the up-line andsausage I had sent up earlier to mark the spot, and finish my deco there.Unfortunately, I couldn't find the line. I thought for sure I was exactlywhere I had put it, but it just wasn't there. It was starting to get verydark, so I decided that I just couldn't see it (I later found out the linehad broken and the sausage had drifted away). I did my best to maintainposition in the current, and finish off my required deco. Surprisingly, thecomputer indicated that only a few minutes were required, but given theextra heavy workload and yo-yo profile, I figured I'd do some extra deco. Just as I was beginning to worry about how the boat would find me without areference float, I saw a rather large shark approach. There was just one,and I could see it was a Gray, not a Galapagos, so I wasn't worried. To mysurprise, however, it came straight in for a close pass and then beganclassic threat-display posturing. This is the behavior known to Gray reefsharks where they drop their pectoral fins and start swimming in a highlyexaggerated sinusoidal pattern. It is the behavior these sharks do justprior to attacking. Bolting Galapagos sharks may be unnerving, but that isNOTHING compared to a large posturing Gray reef shark - this was serious. Itried slowly backing away, but the shark continued to get more agitated. Anacquaintance of mine named Mike DeGruy was in the presence of a posturingGray reef shark once, and the shark ended up ripping his arm apart, nearlykilling him. With this in mind, I looked at my computer, which said I owed afew more minutes deco. Taking all the issues into account, I again relied onthe conservatism of the computer, ignored the heavy workload on the bottom,and got my ass back in the boat. Knowing that I was pushing my luck from adeco perspective, the first thing I did was grab some oxygen and startbreathing it. I breathed it for nearly an hour straight, all the whileassessing for any sign of bends, while watching the other crew recover theanchor. No symptoms. Lucky me - I cheated bends once again. We had a lot of fun talking about the exciting events of the day. I was abit nervous about having two days in a row of breaking deco due to sharks(that's normally not supposed to happen), and sort of thought about how theheavy workload and long bottom times at 90-120 feet or so must be pushing mytissue loading out towards the limit. You would think this would cause meto be extra-super-duper careful for the remainder of the trip. You wouldthink I would have thanked my lucky stars, and chilled out a bit. You wouldthink. The next day, Tuesday, was our last day of diving. I wanted to make itcount. I did a mellow morning dive and scouted out the ledges under theboat with my video camera. Again, the same sort of ledge at the same sortof depths, and the same sort of benign daytime shark action. For theafternoon dive, we wanted to make sure we didn't end-up down current of theboat, so I and two of the OC divers shared a ride on a single DPV and madeour way several hundred yards straight up-current of the boat. The boat wasanchored at the "mouth" of a large underwater canyon - sort of like anancient river basin. The reef was 80-90 feet on the top, and the bottom ofthe "river" channel was about 120 feet of pure white sand. It was a VERYobvious landmark to find the anchor, so I was cavalier about going way upcurrent on the DPV. Once we got a few hundred yards up-current of the boat,the other two divers veered left with the DPV, and I swam by myself outalong a nice-looking ledge to the right. I came across a fantastic stretchof ledge with lots and lots of fish. I stayed quite a long time, collectinga few specimens, and otherwise having a wonderful time. The workloadchasing the fish and fighting the current was heavier than usual, so Idecided I would do a lot of extra deco on this dive. Once I made thatdecision, and in consideration of the fact that I had hardly seen any sharksat all this dive, I didn't mind allowing a larger deco obligation to accrue(yeah, I know - twisted logic). I waited until I owed about 30 minutes ofdeco, with a 30-foot ceiling before heading back to the boat. It was getting late in the day so I started worrying a little about thesharks, but I didn't see any around. I decided to begin deco on mydown-current swim back to the boat, so I rose up to about 50 feet whilefollowing the ledge contours back to the "river basin" where the anchor was.The current was starting to pick up a bit, so I was moving at a pretty goodclip. I figured I should get back to the boat soon at this rate.Eventually I hit the river channel in the reef and followed it to where theanchor was. Problem was, there was no anchor. The topography looked prettymuch like what I had remembered for the anchor spot, but the sun was nowfading, and I was now up at 30 feet, and I couldn't see the bottom all thatwell. Perhaps the anchor line broke again? Not likely - we were using the2-inch rope this time instead of chain. Maybe the anchor itself broke freeof the bottom? I still owed 20 minutes of deco so I didn't want to go tothe surface, but I finally decided I'd better locate the boat. Still nosharks, so things were O.K. I had some fish that I wanted to keep alive inmy bucket. The fish would have died if brought straight to the surface. Ihad my backup reel and float with me, so I clipped the bucket to the end ofmy reel line, left it at 30 feet, and popped to the surface to look for theboat. I initially looked down current, but saw no boat. To my surprise, theboat was about 250 feet *up* current of me! I later figured out whathappened was that I must have been following the wrong underwater riverchannel - there were apparently two of them side-by-side, and I had managedto find the wrong one on my way back to the boat. At any rate, I now had a predicament. It was getting too dark to see thebottom, and I didn't have a compass with me. Should I go back to 30 feetand swim up-current toward the boat? That would probably be the best optionfrom a deco standpoint, so I turned around to go back down and my heartnearly stopped when I was face-to-face with a large Galapagos shark. I meanhe was REALLY close - like less than a foot away. Usually when a diverturns around to see this sort of thing, both the shark and the diver getstartled; but this time, the shark was utterly un-phased. I, on the otherhand, was reduced to a nervous wreck. I kicked the shark off and it veeredaway, and I saw about 6 or 7 more Galapagos sharks between me and my bucket.Once again it was decision-making time. I basically had two options. The first would be to alert the boat of mysituation, then drop back down and complete deco underneath my backupsausage. The boat could pull anchor and come get me. The problem was, itwould have taken the boat at LEAST half an hour (maybe more) to haul anchorand come get me. The sharks were nastier than they had been the previoustwo days. The current was angled off the shelf and was strong, so by half anhour I would be out over blue water (and God knows what other sorts ofbeasties awaited there). The sun was setting, so it was dinner time in thesea. The surface was very choppy, and my backup sausage is small - what ifthe boat couldn't find it in the dark? Next stop down current would havebeen the Marshall Islands. Bad news. The second option would be to go for the boat and finish deco there. Theproblem with that plan was that I had just completed my third day ofheavy-workload moderate-depth diving, with a series of yo-yo profiles andcut deco times with no safety margins. The boat was a good 250 feet upcurrent (long hard swim). More bad news. Even at the time, I was thinking to myself "What a classic miserablesituation to be in!" Late in the day, hundreds of miles from civilization,down-current of the boat, on the surface owing 20 minutes of deco with lotsof deco factors working against me, mean-ass sharks circling literally at myfeet. It was almost funny. In any case, the first thing to do was alert theboat crew of my position. This was easily accomplished with my trustyair-horn on my BC (now permanent part of my equipment). I almost decided togo with the drifting deco option, when I saw the stern line float only about30 or 40 feet away. Thank God for stern lines! That was the decidingfactor - I would get back to the boat first, then finish deco under theboat. Much better option, all things considered. So I called for afree-diver to come help me, and to bring a spear. They missed the partabout the spear. When Scott (one of the other scuba divers, who I didn'tknow before the trip but now have great admiration for as a level-headed,highly talented diver) arrived wearing only mask, wetsuit and fins, hisfirst response was "Oh shit!" when he saw the sharks. By this time, with meswimming toward the boat against the current, my bucket and fish had beendragged up to the surface, The sharks had followed the bucket and werecircling back and forth between it and me. It was pretty classic - abovewater I could see my bucket at the end of its line down-current of mebobbing at the surface, and all between me and it were these dorsal fins andtails of sharks thrashing around. Again, it was almost funny. Without a spear, Scott couldn't help me much. I was actually concernedabout the well-being of my fish, so I sent him back to the boat to get a2-lb weight to put in the bucket to keep the fish down under pressure.Meanwhile, I took my rebreather off my back, inflated the BC andcounterlungs, positioned it under my belly, and started swimming like madfor the stern line. I decided to pretend the sharks weren't there, so Icould concentrate on getting to the line. It's not like I could do a hellof a lot about them anyway. Fighting the current with all that gear and a5-gallon bucket in tow, it was an EXTREMELY hard swim that lasted about 5 or6 minutes. I finally got to the line, and clipped my rebreather off to it.At this point I had a moment to relax and assess how I felt, and as far as Icould tell I was O.K. My stomach felt a bit ill (likely due to swallowingsea water in my fight back to the stern line - or so I reasoned), and I wasa bit short of breath, but otherwise I felt O.K. I mustered the courage tolook back at the sharks, which was a mistake because not only were theystill there and still agitated, but one was in the midst of a charge on me(something that had no doubt been happening for my whole swim back to thestern line). Fortunately, most of the sharks were back at my bucket, about30 feet behind me. The fish, being on the surface, were under a great dealof stress, and were no doubt sending signals that were getting the sharksexcited. The sharks were continuously bumping the bucket, but at least theyweren't bumping me. Shortly thereafter, Scott arrived with the weight. At this time I had tovoluntarily drift back to the bucket, among the sharks, and drop the weightin the bucket. That task was pretty damn spooky (as I started to driftback, Scott said something like "I wouldn't do that if I were you!"), butotherwise uneventful. The sharks were close and continued their passes, butthey were still focused more on the bucket than on me. Freed of the burdenof the rebreather and the bucket, I was able to quickly pull myself alongthe stern line back to the boat, while the crew hauled in the gear and fish.Back at the boat, I had a moment to catch my breath, and assess mysituation. Although I felt fine, I knew I needed to get back down on oxygento finish my deco, so I quickly climbed into the boat to get the emergencyoxygen cylinder. One of the scuba divers had used it earlier as a safetymargin on his deco, and the tank hadn't been refilled. It was a steel 50cfcylinder, and it had about 800psi left in it. I was about to re-fill it,when I suddenly noticed that I was getting shorter and shorter of breath,even though the opposite should have been happening. Also, my abdomenstarted cramping up very painfully. I realized that the symptoms were nowgetting very severe, very quickly, all within about two minutes of climbinginto the boat. My breathing was now getting VERY hard - like I wasbreathing too much CO2, except I had none of the other symptoms associatedwith CO2. I had to act immediately, so instead of re-filling the oxygencylinder, I grabbed it under my arm, put my mask and fins back on, androlled over the side. I pulled myself down to about 28 feet and breathedthe oxygen deeply. I was breathing very hard, and coughing violently(classic "chokes" bends symptoms) and my abdomen felt tight as a drum.Within about 2 minutes, my breathing slowed, the coughing abated, and Istarted to feel better. After about 20 minutes or so at 20-25 feet, Irealized that it was almost dark, and the sharks were still there, and Ifelt fine - so I decided to get back in the boat. I walked immediately to the stern of the boat and started breathing the restof the oxygen. For the first 30 seconds or so I felt fine. Then, all of asudden, my eyes were having trouble focusing. I couldn't get both eyes toalign on the same subject. At about the time I started thinking "this isbad", my hands started getting uncoordinated. From that point on, thesymptoms progressed at an INCREDIBLY fast rate. It was less than a minutefrom when I got in the boat until my eyes felt a little strange. Over thenext *sixty seconds*, both arms and both legs started getting progressivelyweak and uncoordinated. In the time it took me to hobble from the stern tothe mid-deck where the ladder is, my symptoms went from mild visiondisturbances to near quadriplegia. I could not believe how fast theyslammed me. With each breath I was feeling noticeably worse. Naturally, my brain could only think of one thing: GET BACK IN THE WATER!GET BACK IN THE WATER! GET BACK IN THE WATER! Unfortunately, I had gottenso bad in the preceding minute that there was no way I could get my fins on.By this time the crew was aware that something serious was up. All I coulddo was bark out commands: "Put my fins on." Someone did. "Find my mask."Nobody could. "Give me ANY mask!" Someone did. "Put it on my face."Someone did. At about this time I probably should have aborted the attemptto get back in the water. However, the symptoms had come on while breathingoxygen at the surface, so what choice did I have? For all I knew,continuing to breathe oxygen would leave me dead or permanently paralyzed.The oxygen tank had less than 200 psi in it so I asked someone to re-fillit. Meanwhile, I managed to roll myself over the side, and Scott jumped into help me. My arms and legs were essentially useless at this point, and Iwas essentially a lump of flotsam bobbing on the surface, struggling to keepmy head above water. I started fearing that I would drown. I was waitingfor them to get the oxygen ready, while Scott was trying to hold me at thesurface near the sailboat, which was pitching up and down about 4 feet. Itwas a really, REALLY messy situation. I was physically a mess, but my mind kept re-assessing the situation -considering the options. I can honestly say that I was still clear-headedand thinking rationally. In such situations, my mind responds by distancingitself from the personal crisis and fools itself into acting as an outsideobserver, watching a movie, trying to think objectively. Given my historywith respect to the topic of In-water recompression, and given the direnature of the circumstances, the default no-brainer response by me would beto insist on being dragged underwater to perform IWR. But my brain wasstill working, and although severe paralysis was far and away theover-riding concern of the moment, I was also very cognizant of the risk ofdrowning. The trouble was, both alternatives seemed so hopeless that I washaving difficulty deciding what to do. At this point (which was about 30seconds after I rolled back into the water) there was still no oxygen ready.Scott looked at me and said "I'm not so sure this is a great idea." Thatwas enough for me: I said, "O.K., get me back in the boat." By this time(less than three minutes after surfacing from my 20 minutes on oxygen), Iwas essentially a sack of Jell-O. I couldn't move my arms or legs. Ittook several people some very serious effort to drag me up the 4 or 5 feetinto the boat, in the pitching sea. They rolled me onto the deck on my backand elevated my feet. I said: "I'll need lots of oxygen and lots of water -quickly!". By this time the oxygen was ready and I stared breathing itdeeply. I was given a pillow and a blanket, and someone came by with a cupof water. The captain of the boat brought me two aspirin (two nightspreviously I had explained to him some of the biochemical side of bends). Hesat me up, shoved the aspirin in my mouth, and washed them down with water.Everyone on the boat seemed to know *exactly* what to do - it was amazing! The next 15 minutes or so could only be described as terrifying. Here Iwas, lying on the deck of a boat, hundreds of miles from a chamber, almosttotally unable to move. The symptoms were nearly identical to the seriousbends I had twelve years ago, which means the insults were probably in thesame regions. It had been very clearly explained to me that the last time Iwas bent I had essentially used up all my redundant neurons to recover myability to walk, and that if I ever got hit in a similar way again, chancesfor recovery would be extremely slim. The symptoms had come on *extremely*fast even while breathing oxygen on the boat -- who knows how worse theywould continue to get? Moreover, why would they now suddenly go away? At the time, I had absolutely no idea why....but miraculously, the symptomswent away anyway. In fact, after only 15 minutes of surface oxygen, I hadnearly full strength and coordination back in my arms and my legs. At thispoint I started considering the option of getting back in the water. Thesun had already set, the wind was picking up, the sharks could still be seenaround the boat. I decided that if the surface oxygen was working now, Imight as well let it continue to work. Meanwhile, the captain was doing what he could to establish radio contactwith Dr. Bob Overlock, the main bends doc in Hawaii (same guy who fixed meup 12 years ago, and who is now a good friend, and essentially the onlymedical doctor in the State whose opinions on bends and treatment I valuemore than my own). The Captain got through on the radio about 30 minutesafter I started the surface oxygen treatment, by which time I was feelingessentially 100% better. I did whatever I could to assess my neurologicaldeficit, both motor and sensory, and as far as I could tell, things seemedcompletely back to baseline. At that time I took a brief break from theoxygen to give Dr. Overlock a quick summary of the situation. Severalpeople were suggesting alternatives for airlift back to the chamber inHonolulu, but we unanimously and independently came to the conclusion that,given the particular set of circumstances, such an attempt would be morerisky than it was worth. We had plenty of oxygen and plenty of water, so Iwould continue the same treatment regime that had restored my function soquickly. By this time, we started prepping the boat to head back to Oahu. Two of ourcrew were assigned as my tenders, and would take turns over the next severaldays keeping a close watch on me. After a full hour of surface oxygen, Itook a break while we relocated down in the bunkroom of the boat. We hadlarge-capacity oxygen cylinders rigged on deck, and we ran my 50-foot HPhose (normally used for surface-supply oxygen deco) down to the bunkroomwith a regulator on the other end. I changed out of my wet clothes and gotdry and warm in my bunk. The captain set up an intravenous line for salinesolution, to get me hydrated as quickly as possible (as per Dr.'sinstructions). Despite our best efforts with surgical tubing around my armand whatnot, the only good vein I could get on my arm was right on theinside of my elbow. After a couple of attempts in the unfavorableconditions (low light, rocking boat, weak vein), the needle was in my elbow.This meant that I had to keep my right arm straight for as long as we hadthe I.V. line running. Also, we didn't have any medical tape, so we had tosecure it in place with good old trusty duct tape. By this time, the scary part was over, but as it turned out, the real hellwas just about to begin. My instructions were to breathe oxygen for 2 hoursat a time, interspersed with 30-minute air breaks. After the first two hoursegment, things were starting to get mighty uncomfortable. We were on ourway back to Oahu, and the weather was deteriorating. Gale-force winds and12-15-foot seas (by Hawaii measuring standards, which are much moreconservative than the rest of the world's standards) caused the boat topitch and role 45 degrees. It was all I could do not to get tossed aroundthe bunk room. I had woken up early that morning, and had dived hard allday, and it was now getting late in the evening. I was VERY tired. Therolling of the boat caused the "aroma" of the head and its storage tank topermeate the ship's hold somewhat, and combined with the omnipresent dieselfumes from the ship's engine (couldn't use sail power as our destination wasdirectly up wind, and we needed to get there ASAP), all made for a decidedlyunpleasant environment. On top of all that, pulmonary oxygen toxicity wasstarting to kick in. Most divers would not have experienced it that soon -but then again, most divers wouldn't have had three previous days in a rowof multiple long-duration constant 1.4 PO2 dives with high workloads andfrequent surface oxygen binges. Shortly before the end of my first 2-houroxygen stint, I made use of what came to be known as "my little yellowbucket" (which normally holds my drift line) and puked my guts out. Thiswas just the first of dozens of puking episodes to come over the next fewdays. Besides the general unpleasantness of the vomiting, there was a real concernfor dehydration as well. The I.V. was pumping away, but it was being offsetby the vomiting. Also, because I was breathing direct open-circuit oxygen,my mouth and throat were constantly getting very dry and irritated. Ineeded to drink some water for my mouth, but if I swallowed too much of it,it would just cause me to puke again. The pulmonary oxygen toxicity wasgetting worse and worse. All the classic symptoms - irritation in the lungs,shortness of breath, coughing, and most notably, nausea. It was obviouslytoxicity, because it would get worse as the oxygen segment went on, thenwould back off during the air breaks. After about 5 or 6 hours of the oxygentherapy, another problem started creeping in, which I can only attribute tovery low blood pressure. It got to the point where I could not raise myhead more than a few inches above my pillow without feeling extremelylight-headed and faint. Trying to get to the head was an amazingly arduousordeal (even though it was only about 5 feet from my bunk). First, I feltabsolutely MISERABLE! Rarely have I felt that bad before, just in terms ofgeneral nausea and malaise. Moreover, as soon as I tried to sit up (letalone stand up) I'd nearly pass out. The boat was pitching so heavily, thateven perfectly healthy people had a hell of a hard time staying vertical -even while holding onto something. On top of all this, I had to be verycareful to not bend my right arm, lest the I.V. needle tear into my elbow.Just thinking back on it now makes me feel extremely uncomfortable. After eight hours of oxygen, I thought I might actually die. My stomachfelt like a wet rag, and my abdominal muscles were fatigued to the point ofexhaustion (no doubt from all the vomiting) But the oxygen was the mainculprit. Normally, in situations like this, the limiting factor in providingoxygen to the patient is the supply of oxygen. In this case, I had barelytouched our oxygen supply. I probably could have breathed the oxygen forthe entire 3 days without running out of the stuff. Trouble is, after about24 hours of pure oxygen at 1 ata, you start running the risk of pulmonaryedema. Pulmonary edema is the "dark side" of pulmonary oxygen toxicity. Weare taught as mixed-gas divers that pulmonary oxygen toxicity makes you feelbad, but is not life-threatening. The CNS toxicity is what we're alwaysworried about in terms of getting killed. However, if left unchecked,pulmonary toxicity can kill a person. What happens is that the lungs get soirritated that the alveoli start to fill with fluid (edema). As they fillwith fluid, less and less oxygen can be transferred to the blood. If theyfill enough, the diver can get to a point of no return where, 100% oxygen isneeded just to avoid hypoxia, but with that much inspired oxygen, the edemacontinues to worsen. If it gets bad enough, the patient must decide betweendeath by hypoxia or death by drowning, but in any case, death becomesinevitable (at least this is my understanding of the pulmonary edema problemas it relates to oxygen toxicity). I hadn't spent 24 hours on oxygen at 1 ata, but I *had* done three days oflong exposures to 1.4 before-hand. With each cycle of breathing oxygen, thepulmonary symptoms were getting worse and worse and worse. My tenders, whowere *extremely* helpful despite enduring miserable conditions themselves,were last instructed to "keep giving him oxygen". When I started mumblingabout taking a longer break from the oxygen to recover a little, they werepretty adamant to follow doctor's orders. In fact, we had gotten a set ofear plugs which I stuffed up my nose to help make sure I was breathing onlythe oxygen - especially if I were to fall asleep. I knew the oxygen supplywasn't going to run out, so I kept persisting for a break. Finally, I hadto, as best I could, explain what pulmonary edema was and how it might applyin this situation, and how it might kill me. They weren't sure if I wasjust delirious, or if I knew what I was talking about. Finally, they agreedto give me an oxygen break. Over the next two hours my condition improvedsomewhat, so they decided they had made the right decision. With the cessation of the oxygen, I thus began the long road to feeling likea human being again. The vomiting continued with decreasing frequency forthe next 24 hours or so. Over that time, I was slowly able to ingest water,and eventually the I.V. was removed. Slowly my blood pressure started tocome back. However, even though my body was coming around somewhat, theboat continued to pitch unbelievably, and since I lacked the energy to gotop-deck I had to endure it in the unpleasant atmosphere of the bunk room.Three and a half days, non-stop, 24 hours a day. Among all the fun timesI've had in my life, this experience was most certainly not among them. We finally pulled into the loading dock on Oahu Saturday morning at 2am (Ihad been bent Tuesday evening). During the journey home, I did everything Icould to assess my neurological condition. Sensory seemed fine (using ahypodermic needle to prick various parts of my arms and legs). Strengthseemed fine (except for the general whole-body fatigue that was shared byeveryone on that boat, given the conditions of the ride home). Reflexesseemed fine. Coordination was, as best as I could determine, fine also. Theonly thing I couldn't do (and an acid test for lower-body neurologicaldeficit) was test my balance. The boat was rolling so badly and without abreak, that nobody on it could keep their balance without holding ontosomething for dear life. Thus, when we finally got to the dock, I wasanxious to get to terra firma and assess my balance for the first time sincethe bends symptoms. I jumped to the dock, and promptly fell flat on my ass. I tried to stand up,but could not for the life of me stay standing - I kept stumbling over. Forobvious reasons, I took this as a very, VERY bad sign. However, it soonbecame evident as others jumped ashore, that NOBODY (save for the Captain,and Scott, both of whom had many more hours at sea than the rest of us)could stay upright without holding onto something. After that rolley-polley80 hours at sea, we all had a bad case of "sea legs". We looked like abunch of drunks staggering around the parking lot. As it slowly wore off, Iconvinced myself (and later confirmed) that it was, indeed, just sea-legs,and not neurological residuals from the bends. My house is only about a 10-minute drive from the dock, so I got a ridehome, picked up my truck, and came back for my gear (hoping not to getpulled over for drunk driving). My stomach felt like it was made of tissuepaper, and every muscle in my body ached, and the whole world was rockingback and forth, but otherwise I was O.K. Very, very tired, but O.K. Thenext morning I woke up and my room was spinning. I felt a bit off centerall morning, but felt good enough to drive in for a visit with Bob Overlock.I told him the story, and he left it up to me whether or not I felt a tripin the chamber would be worth it. I thought not, and he agreed. Over thenext few days, I gradually regained my feeling of well-being. I am writingthis on Thursday, October 8 - nearly a week after getting back from thetrip;10 days after the bends. To the best of my abilities to determinethings, I am fully restored to pre-trip health (except for some cuts andbruises). I plan to take at least another week off from diving, then maybestart slowly again. RETROSPECTIVEI can think of dozens of little mistakes that I made throughout the dive trip that led to the ultimate outcome. Most of them are pretty obvious.For example, I should have had a compass if I was going to do a lot ofdistance-swimming diving. Also, I had my surface-supply oxygen rigavailable - but I didn't have it set up and ready to deliver oxygen. Isuppose it could be argued that some sort of shark protection device couldhave been used, but that one is debatable. Probably most significantly, weshould have had the small inflatable chase boat set-up and ready to go.That alone would have solved many of the problems encountered during thetrip. However, all these little mistakes fall under the one REAL mistake Imade this trip. I kick myself for this, because not only should I knowbetter, but in fact I DID know better a few years ago, but have sinceforgotten. The mistake I made was that I neglected to take dives to depthsof 90-120 feet seriously. Years ago, after I had been making trimix dives for quite a while, I startedcatching myself getting cavalier about doing dives in the 90-120 foot range.For any trimix diver, this is an easy trap to fall in. For many of us, 100feet is fairly far up a long list of decompression stops. After a dive to400 feet, arriving at 100 feet is like arriving to a safe haven. So, itoccurred to me, years ago, that 90-120 feet was probably my most dangerousdepth range, because it was deep enough to get in serious trouble, butshallow enough by comparison to the helium dives that it was hard for me totake them seriously. Buried deep within the TechDiver email archives aresome posts from me ranting on about this very issue. Problem is, I forgot. I forgot about that little rule of thumb. I fellback in the trap of "Oh, it's only a hundred feet or so....no big deal." Nobig deal if I end-up down current of the boat, because I can always breakdeco and swim to the boat. No big deal if the sharks get nasty, because Ican always break deco and get to safety. No big deal if I have to work hardon the bottom, because hey - it's *only* about a hundred feet deep. What'sthe big deal? The big deal, of course, is that 100 feet is PLENTY deepenough to suffer crippling bends - even using constant-PO2 rebreathers.This is especially true if the workloads are high, and the profiles areyo-yo, and no safety margins are incorporated. I was reminded of thisreality (rendered extraordinarily obvious in hindsight, but remarkablyobscure at the time - which tends to be the case for most causes ofaccidents) from this incident, and I do not intend to every allow myself toforget it again. My big concern is: what else have I forgotten? There are some topics thatwe discuss on the email lists to the point where they become so obvious thatthey are branded on our minds. We get bored of discussing these issues overand over again, so we stop discussing them. Eventually, after months oryears of carefully avoiding topics which we thought had already been beatento death, we allow the new topics of the day to clutter our minds are nudgeaside the basic obvious tenets. Things such as "yes, 100 feet is plentydeep to get into serious trouble". So, perhaps we should not object sostrongly to reminding ourselves of some of these old "obvious" issues, andlet some discussion topics rear their heads again from time to time. This incident also allowed me to re-evaluate some thoughts on bends andbends treatment. Of particular note, I am thinking now that blooddistribution within the diver's body may play a much larger role in bendssymptoms than I previously gave it credit for. I'm not just talking aboutperfusion issues - I'm talking about how blood redistributes in a diver'sbody depending on whether the diver is submerged in water, or exposed to thefull effects of gravity on land. When a dive is underwater, the effects ofhydrostatic pressure essentially eliminate the effects of gravity on theblood distribution. The result of this is that the diver's blood initiallypools in the body core. In time, the body compensates for this by dilatingvessels in the lower portions of the body, and constricting vessels in theupper parts of the body. When a diver suddenly leaves the water and returnsto the world of gravity, there is a sudden rush of blood from the body coreto the lower extremities. It takes a few minutes for the body to compensatefor this by re-adjusting blood vessel dilation levels in different parts ofthe body. The net effect is a sudden loss of fluid from the body coreimmediately upon exiting the water. Consider what happened: I violated 20 minutes of deco, then spent 10 or 12minutes working hard as hell at the surface, trying to get back to the boat.No symptoms throughout this entire ordeal. I get back to the boat, catch mybreath, and feel fine. However, within a minute or two of leaving thewater, climbing into the boat, I start getting chokes and abdomen pain -with rapid progression. I get back in the water and the symptoms go awayvery soon. Could be explained by the breathing of oxygen, or the increasedambient pressure, or both. But what about the role of re-immersion and it'sgravitational/hydrostatic effects on blood distribution in the body? Now, 20 minutes of pure oxygen at 20-25 feet and I feel great. All thingsconsidered, my body is probably better-off at this point than it was when Imade my first break of deco down-current of the boat. Maybe not - maybeit's worse - but it couldn't be that much worse - the oxygen and pressuremust have had at least some therapeutic effect. The issue is, within aminute of getting back in the boat *while breathing oxygen*, the symptomsreturned more suddenly and more severely than they had come on in the firstplace. This, despite the fact that 10 minutes of hard labor (but still withmy body in the water) immediately following the dive led to no symptoms; yetless than a minute after climbing in the boat following oxygen at 20 feet, Iget whacked like a sledge hammer. Also keeping in mind, the symptoms cameon *while* breathing oxygen, sitting in an upright position. Next, I botchmy IWR attempt and breathe oxygen on the deck of the boat - this time lyingdown with my feet elevated. The *only* difference really between thesituation where breathing surface oxygen led to severe symptoms, andbreathing surface oxygen led to reversal of symptoms, was the position of mybody. Lying down with my feet elevated, I had as close to animmersion-distribution of blood in my body as any position under theinfluence of gravity. The onset of symptoms did not seem correlated tightly with fast ascents, orheavy workloads at the surface, or even breathing or not breathing oxygen.They were, however, *tightly* correlated with climbing out of the water andinto the boat. Maybe this gravitational effect on our blood distributionimmediately after immersion has a much larger role in bends symptoms thanmost of us give it credit for. Nothing in my recent experience in any way"proves" this, but Dr. Overlock has been telling me for years that thisparticular aspect of post dive effect (gravity and the hydrostatic effectsof blood distribution on the body) may play a very big role in bendsmanifestation. If this does turn out to be a really important factor, then I can see acouple of interesting implications: 1) Perhaps our last deco stop should not be at 10 or 20 feet, but should beat the surface. Maybe we should spend some time floating on the surfacebefore climbing out of the water. Perhaps more importantly, maybe we shouldalways lie down with our feet elevated following a dive, to allow ourcirculatory systems to gradually adjust to the sudden change in hydrostaticeffects and gravity, instead of slamming our bodies with a major blood-shiftat the exact worst time to induce bends (following a dive). 2) This one interests me more. Perhaps there is an alternate form of"In-Water Therapy" in response to decompression illness symptoms thatbridges the gap between surface oxygen only and full-blown IWR. Maybe onealternative treatment is to allow the diver to float at the surface andbreathe pure oxygen. This lacks the benefits of increased ambient pressureafforded by IWR, but reduces the risk of drowning carried by IWR. If theeffects of immersion on the circulatory system do play an important role,then this could be a WHOLE lot better than simply breathing oxygen on theboat. Perhaps, when I had returned to the water for my botched attempt atIWR, symptoms would have been restored better while floating at the surfacebreathing oxygen than they were for me lying on the boat. Indeed, what ifthe amazing success rate of air-only IWR has little to do with increasedambient pressure, and much to do with hydrostatic effects of immersion onthe body's blood distribution? Maybe breathing oxygen (or even air) at thesurface would be almost as effective as IWR? What would we call thistreatment? Maybe "IWSO" - In-Water Surface Oxygen. Food for thought.Finally, I'll describe a rather funny side-story to this bends incident. One of my deep rebreather diving companions is Joe Dituri, who works for theUSN. Apparently, Tuesday evening he received a call relating to a possiblerequest for a military C-130 to go out to French Frigate Shoals in thenorthwestern Hawaii Islands and pick up an injured civilian diver, shouldthe need arise. He knew I was diving in the northwestern Hawaiian Islands,but not at French Frigate Shoals, so he didn't think much of it. (What hedidn't know was that FFS is the closest place to Necker where a plane mightbe able to land, and one of the options being considered for my airevacuation was to get me to FFS and fly me back to Oahu by plane instead ofa helicopter pickup directly from the boat.) Meanwhile, Bob Overlock, who was notified Tuesday night, is on theUniversity of Hawaii Diving Control Board (as am I). The boat we were onhas often been chartered for use by U.H. projects, so he thought I mighthave been making an official U.H. dive (which, thankfully, I wasn't).Therefore, he felt it was his duty to call Dave Pence, the U.H. Divingsafety officer. Now, Dave is a very good friend of mine, a SUPERB diver, asstudent of Joe's. The three of us (Joe, Dave and I) dive together often,and Dave has served as a safety diver for us. Dave is also very-much amother-hen type person, as his job essentially dictates. Dave had donecharters on this same boat before to other northwestern Hawaiian Islands,and he knew I was onboard this boat at Necker. After hearing of my situation, Bob Overlock felt compelled to call up Daveto find out if it was a U.H. matter. He did not mention my name, but simplyasked "Do you have any official U.H. divers in the northwestern HawaiianIslands." Given this, and given the person placing the call, and givenDave's knowledge of me diving in the northwestern Hawaiian Islands, combinedwith his uncanny ability to put two and two together, Dave responded "No,but how is Rich doing?" Bob couldn't tell him without explicit permissionfrom me (which he couldn't obtain because of the tricky radio connection).This, of course, left Dave feeling very uneasy about my well-being. Thatprompted him to call Joe. Joe, as soon as he heard this, recalled thepossible request for an airlift, put 2 + 2 together himself, and both gotvery worried about me. Now Joe and Dave had a predicament: "Do we tell Lisa?" As they knew, Lisateaches at U.H., which makes it very difficult for her to solo-care for Carawhen I am out of town. She was going through a bit of a hell week of herown, dealing with grading mid-term exams for 160 students. There was nothingLisa could do about my situation, and no way for her to contact me until theboat returned several days later. If Joe and Dave told her I had been bent,and that they had no idea how I was doing, that would have TOTALLY wreckedLisa's week. She would have been going nuts wondering what was happening,with no way to find out. So, Joe and Dave finally decided *not* to tellLisa, because, they figured, if I could radio Dr. Overlock, I could alsoradio-contact Lisa, if I felt she needed to know (which, of course, I didnot). Making this resolution, however, did not ease the concerns of Joe and Davefor my well-being. Surely, they thought, if it was serious I would callLisa. When I staggered home at 2am Saturday morning, Lisa woke up and I toldher it was an "eventful" trip, and I would fill her in on the details thenext day. Before going back to sleep she said: "Oh, by the way, Joe's beenleaving messages every day. What's up?" Of course, Lisa's schedule was sothick that week that she was never home, so Joe never actually talked toher. I listened to the message machine and heard message after message fromJoe to the effect of "Hi Lisa, it's Joe.....umm....just wondering if thereis any word from Rich about his trip. Well....umm...give me a call if thereis. Bye." At this point, I had no idea that Dave and Joe knew of mypredicament, so Lisa and I just decided Joe must have missed his daily phoneconversations with me, and was calling Lisa just for the hell of it. Infact, he was fishing for details, in case I had contacted Lisa directly.The fact that Lisa never returned Joe's calls (she was averaging 3 hourssleep every night, so really didn't have the time that week), probably madeJoe even more concerned. Anyway, we all had a good laugh afterwards, and we all got clear on thepoint that, if there's nothing Lisa can do in the event I get hurt, andthere's no way for her to get more information right away, then she justplain doesn't want to know about it. Especially if it's mid-term exam week. |