EXPLORATIONS AT MYSTERIOUS LAGOON -

EXPLORATIONS AT MYSTERIOUS LAGOON - BRAZIL

Gilberto Menezes De Oliveira

“This time you did it,” I said to myself. You are going to stay stuck here till you run out of air and it is going to take a long time before anybody will come and recover your body! I was in a terrible situation: 96 meters deep on air, inside a cave system never before dived, couldn’t see a thing, and my doubles wedged in something so tight, I couldn’t move! It had all started the year before…

I first went cave diving during a vacation in December l994. I had, for several years, been reading about cave diving and found the activity fascinating, but had not had the opportunity to go cave diving until then. I had studied the NSS manual, Sheck Exley’s Blueprint For Survival and a few others. The book The Darkness Beckons was a sort of Bible to me: it was the greatest book on diving I had ever read. I would read it over and over again. All these incredible explorations! I dreamed of one day doing it also. But I had no formal training on cave diving. I did try to self teach me. I would often go to Paraibuna Dam which is a place fairly close to where I live here in São Paulo. There we have a lake formed by the dam in the early l970’s which has low visibility, fairly cold water , lots of silt , trees to get entangled, but most important it went very deep. It’s a perfect place to practice. Over the years I practiced going deeper and deeper until I became quite comfortable diving 80 to 85 meters (275 feet) deep with run times of 3 to 4 hours. All on air. Of course I had my share of problems during the learning process and on two oxygen hits the dam nearly swallowed me. I was learning by survival. It is not the best way to do it.

My first cave dive happened on December 1st, 1994 in a cave called “Gruta do Mimoso” or Mimoso Cavern. Mimoso Cavern is situated in the Mimoso Farm in Bonito county, in the state of Mato Grosso do Sul. It is located a distance of about 1200 kilometers by road west of São Paulo. I got hooked immediately. The cave was beautiful. Mimoso was once a dry cave that eventually got filled with water so it has many cave formations like stalactites, stalagmites, etc. Visibility was crystal clear, water warm and the passages were big. All that I wasn’t used to. The cave did not extend very far and in another 5 dives I already knew it very well. On these dives, we used basically cavern dive equipment, diving on single tanks. It was when I met Roger which was my dive guide on the Mimoso dives and we would start an important friendship. I also met the owner of Mimoso Farm, a lady which would be very important, Maria Aparecida, or as I would call her for short, Cida. Cida is a very religious mother of two on her second marriage. Besides running the Mimoso Farm with her husband, she also runs a lodging in her farm dedicated to tourists that come to Bonito including divers.

Diving is rather new to the region around Bonito. By what I know diving began there in the l980s in a cave called Gruta do Lago Azul (Blue Lake Cavern). It is probably the most beautiful cave dive in Brazil. It, unfortunately, is also the place of the first cave diving fatality in Brazil. Unfortunately, also, it has been closed to diving for several years due to some non-diving classroom biologist who thinks that in that only cave exists an unique species of a shrimp like creature. We have found it in all other caves we dived but she won’t hear us. Then I had heard about Bonito a few years ago because of an accident one diver had diving deep on a lake there. Reportedly the diver had gone to a depth of some 80 meters and run out of air ascending without decompression. He got bent very badly, was taken to São Paulo for recompression treatment and luckily recovered. Then I heard about diving in Mimoso Cavern. Having the opportunity to go there, I went.

It didn’t take long for me to start asking Roger if there were other caves to dive in the Bonito area. Roger explained that the potential in the area existed for many more caves but exploration had to be done. A few others, already discovered, existed though. There was a place known as Abismo Anhumas. Roger took me there. Unfortunately you have to rappel a vertical distance of 66 meters (220 feet) which was out of the question for me. He told me of Formoso Spring which had been dived by French divers a few years before but unfortunately the land owner did not like divers on his land. Permission to dive there would be very difficult. Then he told me about this lake that’s supposed to have crystal clear water but unfortunately was very hard to get to the site and worse it was a closed site to divers, by order of the landowner, since an accident to a diver there, a few years before. Roger was talking about the place the diver had had the decompression accident. The name of the place: Lagoa Misteriosa or Mysterious Lagoon.

Insistence pays off. After talking a lot with Roger, Roger talking a lot with a lot of people we were granted permission to make a dive in Mysterious Lagoon. So in March l995 I was back to Bonito to make a couple of dives in Mimoso Cavern and one in Mysterious Lagoon. We went with Claudio, the owner of another farm in Bonito, who got the permission with Mr. Julio the owner of the farm where Mysterious Lagoon is situated. The dirt road was very long. Then at one point, already inside Mr. Julio’s farm, Claudio’s pick up truck starts going through the middle of the pasture. At one point, we stop as the vehicle can’t go any further because of the trees. Then we walk. And it is hot also. Then we get to this rock path nearly vertical. And we follow it down. And we are carrying our dive gear also. Just to get to the dive site was an adventure. We weren’t tired though. We were excited we were going to make the dive. When we got to the end of the rock path what we saw was an oval lake some 60 meters by some 25 meters. The lake was situated at a bottom of a depression on the land some 40 meters down with near vertical walls all around with original vegetation. The dive was planned for Roger and I to go first. I asked to everyone to be very cautious because this was a terrible place to get into trouble and also because if we did everything right we probably would be granted permission to return. The place had been closed because of an accident. I would go first with the reel with Roger close behind. The plan was to go no deeper than 40 meters (133 ft). We wore single OMS 121s with H valve and two regulators. This was something new to Roger who was used to single 80s. Doubles were out of question due the logistics involved. I remember Roger telling me over and over again how clear the water was there because he had seen this video of the place. He insisted that no lights were needed there. Roger didn’t take any. Stubborn as I am, I took 2 lights attached to my helmet and an extra on my pocket. The water was terrible. Visibility had been greatly reduced due to rainfall. I started using one of the lights of my helmet and handed the spare one to Roger. I had done the initial tie off on a rock by the waters edge and we started following the bottom which was covered with fine silt. We couldn’t see much. At 15 meters it cleared and became vertical. We were in a sinkhole about 10 meters in diameter. We kept descending with caution and halted at 40 meters looking for a projection to tie the line. There was a good one a little deeper and so the tie off was made at 42 meters. Having done what we had proposed, we started ascending. We saw that it went deeper. After surfacing Roger took the others for a short dive.

In April I returned with Roger for another dive in Mysterious Lagoon. This time the water was crystal clear. Swimming at the surface we could see that there were 2 sinkholes starting at about 12 to 15 meters deep, both about 10 meters in diameter. The water had this beautiful blue tone though the bottom wasn’t very pretty as it is covered with brown silt and several logs and branches fallen from above. We had made our first dive on the sinkhole next to water entrance, Sinkhole A, so this time we decided to dive the other sinkhole on the other side, Sinkhole B. At 17 meters there was a very convenient horizontal log where I did the initial tie off and we continued downwards. The sinkhole was basically vertical without any side tunnels that we could find. We had planned not to go no deeper than 60 meters (200 ft). At 57 meters there was this tree branch on a ledge where I tied the line. We looked around for a short time at this depth. We could see that it went deeper but could not see were it ended. Swimming in the direction of Sinkhole A there seemed to be a tunnel but we did not want to swim far from the line to investigate and soon it was time to come up.

Suspecting that there could be a passage between both sinkholes I returned in May during my vacation with Roger to try the connection. At this point we were still diving on a single OMS 121 with H valves but now I carried an extra Genesis 100 and dove with Superwings. We descended on Sinkhole B. At the end of my line I noticed the tie off was not 57 but more closely to 59 to 60. I looped new line here and we started swimming in the direction of Sinkhole A. We saw this big tunnel some 10 meters across with clarity far away. I could see that there was a passage. We went a little deeper, to 68 meters (225 ft), and the tunnel ascended at an angle. Getting shallower I started looking for my 42 meter (140 ft) tie off of Sinkhole A. And soon, there it was! Joining the lines Roger and I shook hands and ascended.

Two days later Roger and I returned for another dive. The plans were to take another look at Sinkhole B, possibly going a little deeper and, if everything was alright, to make the sinkhole passage.

We descended Sinkhole B to the tying point at 60 meters and I looped new line and started descending at an angle. I saw this boulder next to the still vertical wall with the bottom of the boulder on a steeply inclined bottom. I passed the line around the boulder and tied it. Depth 75 meters. Everything alright, we started ascending and swimming in the direction of the passage. Doing the sinkholes passage again we ascended. On all of these dives, we were decompressing on dive computers, the old model Aladin Pro. We would always over decompress what the computers indicated.

On the following days, I started diving Formoso Spring with Gilson, a young local diver who acquired the necessary permission. But less than a week after the last dive in Mysterious Lagoon, back I was this time with Gilson but without Roger. Roger had work commitments as a dive guide in Mimoso Cavern. I took Gilson to make the sinkholes passage but this time, on our way up Sinkhole A, I decided to explore a side passage Roger and I had noticed on the previous dives. The passage started at 34 meters (115 ft). There is a tree branch at the beginning of the tunnel which is wide enough for one diver to pass easily but not two. The bottom had fine brown silt and the tunnel continued descending at an angle of about 30 degrees from horizontal. At 46 meters opened a small room with a small ledge but no bottom. I made a signal to Gilson to wait for me here because we had not passed a line and I wanted to take a look deeper. I started descending. I was in a crack about 2 meters wide and a very irregular 10 to 20 meters long. The walls weren’t smooth but rather rough and irregular with fine silt on the walls. This is consistant at Mysterious Lagoon. At 60 meters I stopped my descent and could see way down what seemed the end of the crack where there was a rock on the bottom. I ascend worried about not having a line and the percolation from the air bubbles. Luckily I could see Gilson’s light and we exited the tunnel without problem.

The next day I was back with Gilson. The plans were that we would pull a line starting from the main line in Sinkhole A, and go inside the side tunnel. Gilson would wait for me at the ledge at 46 meters while I descended. All went well. As I descended I could see the rock at the bottom getting closer, and could see also, that beside it, and a little deeper there was a restriction and the cave would go on. I reached the bottom and proceeded to tie the line on the rock. In the process the visibility turned to zero. Working by feel I wasn’t getting a good loop around the rock. Eventually it stayed reasonable, but not good, and not wanting to stay too long, I ascended. I had been at 82 meters (275 ft).

The next day I decided to repeat the dive to check my tie-off at 82 meters. We would also check a possible continuation at the ceiling of the small room at 46 meters that Gilson had noticed. The tie-off at 82 meters wasn’t bad but as a safety measure I clipped a 1 Kg weight to the loop. In case the loop would come loose from the rock the line would still hang vertical. I also checked the restriction. Not too small, but with a tank on the back and another clipped diagonally in the front, as I was doing, I wouldn’t pass. I could see that the cave continued on the other side of the restriction. I also thought that to negotiate a restriction at 82 meters on air would be a very dangerous move. On the way back we checked the ceiling of the 46 meters room. We passed line, starting at 46 meters by making a tee on the main line, to 35 meters. At this point percolation was a big problem and the tunnel seemed to get tight.

Whenever I laid line I also would put direction arrows which I home made. I would put quite a few. At the 46 meter room I put one of them indicating the exit right after the tee we had just done. Coming up through the crack you would notice a “T”, one line going up and another going to the right with the arrow indicating the exit.

In June I came back and I decided to reach the bottom of Mysterious Lagoon. Sinkhole A tapered off through the passage to Sinkhole B, not going any deeper than about 60 meters. But Sinkhole B would go deeper. I expected it to end shallower than 90 meters, a depth that I was used to diving in Paraibuna Dam. Anyway, I knew things were going to start to get more dangerous. I knew I had to start diving with proper equipment configuration and so I decided to start diving with double tanks in the lagoon. By this time, we were already getting used to the steep rock path we had to negotiate to get to the water and a rope had been fixed along it, so going down with doubles in the back was not too bad as we could now hold to something for balance. The place had finally been opened to tourist divers. My equipment consisted of double Genesis 120 on a Dive Rite back plate with Superwings. The primary light was a mini Neutralite waist mounted with the MR-16 head helmet mounted. On the helmet, I also wore 4 back up lights. I wore two of the old model Aladin Pro dive computer on the left forearm along with the knife and the Uwatec digital depth gauge on the right forearm. I carried also, clipped to my left side an OMS 121 tank filled with air. Regulators were all Poseidon Odins. Resting at the surface, I try to visualize my dive, a technique I tried to learn reading materials by Tom Mount. Breathing from the stage tank, I descended, not to quickly as I felt that this helped fight narcosis. Reaching 75 meters I looped new line to the tie off. Having done this, I changed to my doubles, checked all gauges and descended. I glided at an angle of about 60 degrees from horizontal following the bottom but reasonably above it. The passage was big. The direction was 90 degrees from the one that we use to make the sinkholes connection. Below 80 meters you finally have a rock ceiling above you. At 80 something, I see, just a few meters below me, a tree branch sticking vertically from the slope bottom, a perfect tying point. I go to it. I always wondered what the computers would indicate if I descended below 99.9 meters. Would it zero and start again or if it would continue without the decimal point? I check my depth on the computers: 5. something in one and 6. something on the other. Here narcosis plays a little trick: instead of assuming I was at 105 or 106 meters, I thought I was at 95/96 meters. Still I thought: I’m deeper that I thought it would go. I also saw that the cave kept on going down. I make the tie off, attach line arrow, take a quick look down and ascend. At 60 meters I meet Zé Roberto, an open water instructor from São Paulo who was visiting Bonito and hearing about the dive I intended to make, volunteered as a safety diver. We had planned to fix the 60 meter tying which needed improvement. After fixing it we ascend for decompression. I then show him the gauges so he would know how deep I had gone. At this point I see that the digital depth gauge indicated 106 meters. At first I thought that it had malfunctioned but later I realized what happened. Gilson approached to see if everything was OK. During deco, Zé Roberto ran low on air (he was diving a single 18 liter bottle). I shared my long hose. I was saving my safety diver!

The dive had gone so smoothly, I had felt so well, that I decided to return the next day and repeat the dive, maybe even go a little deeper, just to see if it hadn’t been a chance dive. The only thing that I changed were the double tanks. This time I went with double OMS 121s. It seemed 121 would become a magic number. I ended the previous dive with a lot of margin but, as Tom Mount had written, “Nobody ever died because he had too much gas.” I also took an SOS 150 meter (500 ft) helium depth gauge. I descend and at around 80 meters I change to my doubles. This time I pay attention to the computers l00 meter (330 ft) depth change over. Reaching the tie off at 106 meters I feel well and see another tree branch sticking to the slope bottom a perfect tying point. This time though, I don’t assume that it is just a few meters deeper. I loop new line around the existing tie off and start down. The passage was big, the water would become clearer as I went deeper. The walls were dark and gave a rather spooky feeling to the cave. The top of the tree branch was some 2 meters above the ground which continued sloping at a steep angle. I checked the computers and the digital depth gauge: 121 meters. The SOS depth gauge is remarkably accurate also. I’m deep, I thought. I checked air. I was good. In an upright position and in perfect buoyancy control, I proceeded with the tying. I looped the line twice around the top of the tree branch and let the reel hang while I pulled my knife. My head was clear. I thought in clipping the reel to my right chest D-ring before cutting the line so I wouldn’t loose the reel by any chance. But then I thought that I wouldn’t want to be clipped to the line in case I blacked out. I made the cut, put the knife back to its sheath, clipped the reel to a D-ring and proceeded with the tying. Line arrow indicating exit and a quick look. The water was extremely clear. The slope went on maybe 10 meters (30 ft) more ending in a vertical wall. To the right of when you descend (the direction back to Sinkhole A but below it) I could see what appeared to be the end of the cave, where there were a cluster of boulders and logs, some 30 meters deeper and 50 meters away. I ascend. At 50 meters I meet Gilson. I show him the gauges. The dive had gone so smooth and I felt so well that I wrote in the slate with big letters: 121 METERS (400 ft) - IT WAS SO EASY! I decompressed by the computers, with margins, without incident. I didn’t know then, but some future dives wouldn’t be so easy.

In August I dove Sinkhole A once with Marcus Werneck from Rio de Janeiro and Marcio Conte from São Paulo trying to survey the place. The survey was terrible but we laughed a lot. (Gilberto loves to laugh! ed.)

In September I had vacations again and went back to continue the explorations. I started diving with Roger again. I started to teach him how to dive doubles. He began using my double Genesis 120 and twin wings on a Dive Rite backplate, while I dived twin OMS 121s and superwings. By this time I was already diving with the new model Aladin Pro dive computers. I always dove with two, one read in meters the other in feet. On deep dives I would also carry the digital depth gauge. On our first dive, we dropped down Sinkhole B. I also wanted to test Roger’s condition on deep air dives. We went to the 80 meter range. We noticed a passage on one of the walls and investigated it with care. I was at 83 meters (275 ft) and Roger at 87. It was a vertical crack narrow but tall. We went in just a few meters while I kept an eye on Roger and the possibility of percolation. I soon made signal to Roger to start back as we didn’t have a line and also didn’t want to stay too long at the depth.

The next day I decided to push the restriction at 82 meters in the crack in the side tunnel of Sinkhole A. I new it was dangerous but I believed I could do it. I planned just to take a short look on the other side of the restriction. I planned to carry a Genesis 100 as a stage bottle which I would clip at the tie off before the restriction. This was going to be basically a solo dive so, as usual in these cases, I wore the primary light head on my helmet. Roger would hang a little shallower watching and to give me an assistance if necessary. The dive started as planned. Reaching the tie off I unclipped the Genesis 100 bottle and looped new line. This was enough to silt the area. Passing the restriction was simple. No problem with just doubles on the back. I started going down at the beginning but soon I started to taper off the descent. The water was very clear. I had one wall to the left, another to the right, spaced about 8 meters apart. Looking ahead I could not see where it ended, looking down I could not see the bottom. I checked depth 90 something. 100… I was going further than I had planned. But all was going well, I thought. My head was good, air pressure was good, water is clear… So I went on a little further. I stopped descending at 104 meters and started looking for a place to make the tying. I could see some 20 meters ahead and a little shallower the only place that seemed acceptable so I swam to it. It was 100 meters deep there. I pulled the line, looped it around the projection and proceeded with the cut. In the process visibility turned to zero as the wall was full of fine brown sediment. I started working by feel. It was taking longer than I wanted and I started to feel weary. As soon as I finished tying I started to head back feeling the line. I did not waist time putting a direction arrow. But things were different now. I could hardly see anything and I started to scrape myself on the walls. I had my right arm extended above me holding on the line while I tried to progress. My doubles were scraping and I couldn’t see where. Also, I was hardly getting any shallower. At one point it got stuck but I was able to free myself quickly. By now, the stress level was high. I wanted to get out of there fast because I knew I was too deep for too long for an air dive. Then I really got stuck. My doubles were wedged tight and I couldn’t move them. I checked my depth: 96 meters. At least this I could see. I didn’t bother to check my air as I thought it would be an useless information. I would waste precious time doing so; I had to get out. For a split second flashed in my mind an episode I read in The Darkness Beckons when Mike Boon, gets stuck in a cave and tells himself “This time you’ve really done it”. This time you did it, I said to myself. You are going to stay stuck here until you run out of air and drown and it is going to take a long time before anybody will come and recover your body. I also thought that soon I would start feeling dizzy, and then, that would be the end. But I was holding to the line and I knew that the line would get me out of there if I could follow it. I tried twisting and turning to loosen the doubles but I couldn’t. I did not want to let go of the line which I held with my right hand. I was also afraid of breaking the line. I tried pushing myself down and managed to get loose, stretching somewhat the line and managed to get free. Soon the line became nearly vertical and I started to ascend. I started to hear Roger’s breathing which was a wonderful sound. I passed the restriction without problem even though visibility was bad. I quickly clipped the stage bottle and made signal to Roger to come up. I then checked my air in the doubles: 100 bars. A lot of air but less that I would like. During deco Roger saw my computers and started to rave about the depth I had been. I signaled “no” to him and wrote down on the slate what had happened. I hadn’t looked back as I advanced with the line and when I got to the tying point and pulled the line I had made the line get into line traps in the ceiling. I was lucky I didn’t nark or tox. I started to think about what I was doing. I remembered when I phoned Arnold Jackson a month or so before and told him I had laid line to 400 feet on air: “Gilbert you have to use helium!”

As things were getting too dangerous on the crack we decided to concentrate our dives on Sinkhole B. Two days later we were back. Roger wanted to go deeper and I thought he could. We went to a depth of 96 meters where the line goes over a log. We held there for some 3 minutes to have a good look and ascended. On this dive we positioned a safety air bottle at the 60 meters tie off (a Genesis 100).

Next day we went a little deeper: 104 meters. On this day we positioned another 3 safety air bottles: 2 Genesis 80s at the log at 18 meters and one aluminum 80 at 9 meters at the floor between Sinkholes A and B. I thought that 104 meters was deep enough for Roger and he thought the same.

Next day I decided to dive solo with Roger as safety diver. I wanted to go down the line to my tie off at 121 meters. When I reached the end of the line my primary regulator started to make water. My reaction was to press the power inflator button of the Superwings and come up. I did not think about switching regulators. I later realized how narked I probably was. I had gone a little deeper 124 meters and later found a small tweed breaking the seal of the diaphragm of the Odin second stage.

Two days later I was back again. I had just bought an underwater camera and wanted to take pictures of the place. Actually it was a camera and a camera housing. The system was rated to 100 meters so I thought it would be good enough for 121. Unfortunately the housing had problems and the flash wouldn’t synchronize with the camera. Anyway the flash surely wouldn’t resist the depth. I decided to work with what I had. I attached a mini Neutralite to the bottom of the housing and focused an H-1 head for a medium beam. Set all the rest of the camera in automatic and would hope for the best. I wanted to get pictures of a dive following the line all the way to 121 meters. I secured a lanyard to the housing which I clipped to my left chest D-ring. All the rest of my equipment was as usual: twin OMS 121 on my back, stage OMS 121 secured to my left, primary light helmet mounted. As I was busy with the camera I decided to start from the surface breathing from my doubles. I descended following the line and taking pictures. All went well. I reached the end of the line at 121 meters and took a picture pointing to what seemed the end of the cave. I decided to swim just a little in direction of what seemed the end of the cave to get a better picture. It seemed safe because the room where I was, was very big, the water clear, percolation impossible, surely it was safe to get a little distance from the line. And that was it! The next thing I remember I am holding to a line with my right hand, arm up. It is dark. I check my depth: 100 meters. I check my air: 160 Bars. I couldn’t understand how I had got in that situation. I was in a clear room; why is it so dark? Well, I have a lot of air, this line, it was me that put it and I know that it leads to exit. I just have to remain calm and follow it. And that was it, again! The next thing I remember I’m still holding to the line, the same way, I have this feeling that I can’t go forward because it is tight, it is very dark, I can’t see where I am. I check my air: 30 bars but when I inhale the needle drops to 20. My head is fuzzy. I had this feeling that I have to remove gear to be able to pass but I don’t know why. The regulator is breathing bad. I switch to my secondary: it breathes just the same. I know I’m running out of time. I unclip my camera. It falls. My regulator starts to freeflow. I know the air is very low. I switch the button on the second stage to “minus” and the freeflow stops. I know I have another one free-flowing dangling somewhere. I don’t care. I try to unclip my stage bottle. The waist clip goes easy. The tank is heavy and hangs from my left chest D-ring. My head is fuzzy and the breathing is getting hard. I won’t take my hand from the line. With my left hand, I hold the snap which is tied to the neck of the tank, open the trigger and try to remove it from the D-ring. But the tank is heavy and as I pull up the snap, the D-ring follows the movement and won’t come off. I say to myself: “não desiste, não desiste.” (Don’t give up, don’t give up.) I try again. It doesn’t come off. It’s getting harder to breathe. “Don’t give up.” I try again. It doesn’t come off. My head is fuzzy. I try again. It doesn’t come off. “Don’t give up.” By the 5th or 6th time that I try, it comes off. The stage bottle goes down and I come up. I start to breathe a little better due to the pressure differential. I only have to make to 60 meters (200 ft) where I have the safety Genesis 100 bottle. I vaguely remember checking my computers and had a run time of 30 minutes. They beeped. I’m at 57 meters, hey where is the emergency bottle? I pause for a second. Should I go back to get it? No, it might not be there. I go up. I’m going up fast. It is very hard to breathe. Suddenly a bifurcation on the line and an arrow pointing to the right! My head is still fuzzy. What the hell is going on here? This place looks familiar. I don’t know what is going on but I sure know that arrow is one of mine and it points to the exit. I follow the line and come out at Sinkhole A at 34 meters depth. I think on the air bottle at 9 meters. I think of just going up to the bottle. No, everything is going wrong here. I will follow the line until it “Ts” with the main line and then go up. At this point I realized I had this big pain in the chest and breathing was very, very hard. I thought, at this point that I was bent real bad. It flashed in my mind about suffering very much and ending in a wheelchair. I went up real fast, the computers screamed! I got to the aluminum 80 bottle at 9meters, opened it and started breathing from it. It breathed bad. While I did this, I could see Roger decompressing in Sinkhole B at 12 or 15 meters looking down, to my left, and the log, with the two Genesis 80s at 18 meters, to my right. Should I go to Roger and request assistance or should I go the other tanks? Well, until I explain to Roger what’s going on… I swim to the log. In record time I get one of the Genesis 80s and drop down holding to the line. I knew I had to recompress. I was hoping to relieve my chest pain as I went down but it wasn’t really improving. I pass 30 meters, I pass 40 meters, well, I’m going to stop at 50. I stop at 50 meters. The pain was less but not much. I inflate orally the superwings. I look at my computers: one reads maximum depth 127 meters, the other 422 feet. Runtime was 30 something. Decompression information was blanked on both. At least they didn’t beep anymore. The digital depth gauge read maximum of 129 meters. What had happened? What am I going to do? I stay for 3 or 4 minutes at 50 meters (165 ft) and start ascending very slowly: I can’t stay here forever. I remember to close the valves in my doubles for water could go inside. I ascend one meter at a time. Why doesn’t Roger come here to help me? Suddenly I belch. And the pain in the chest relieves. I’m very worried about my air supply. By the time I reach 40 meters, I had belched several times and the chest pain is much better. Deco information on the computers continued blanked. Then I realize: I can move my legs and arms, I can think. There is still a chance. I remember reading Bret Gillian: It ain’t over till it’s over! If I only knew what decompression to follow and had enough air! Roger, why don’t you to come over and help me?

I continue ascending slowly worried about my gas supply. Suddenly at 32 meters I look at the computers and both were giving decompression information: 6 minutes at 30 meters. I ascend to 30. Now my chances are better. But if I have to spend 6 minutes at 30, imagine how long I’ll have stay on the shallower stops! I don’t have enough air. Roger finally comes down to me. (He later told me that he was looking down during deco seeing if I would appear and thinking that I had died. When someone passed flashing down he didn’t notice it was me. Anyway, it was a wise move not to go after me immediately because I could have been in panic and jeopardized both lives.) I write in the slate what was going on. I was much better then but explained that I would need all the air available. I tell him to drive down to the city to get more air. The 27 meter stop lasted for 7 minutes, and the 24 meter for 8 minutes. Roger still had to complete his decompression before surfacing. That day, a few other divers had gone diving. Tourists and guides. All had about half full aluminum 80s. All had already dived and sent the equipment up. Roger made it all come back. Roger brought all the tanks to me. After some time, I stopped belching and instead, I started to relieve air from the other side of the digestive track. I got worried about having intestinal problems but felt relieved that the pain in the chest had been, probably, because I had swallowed a lot of air. During the long decompression that followed I eventually realized what had happened. When I narked, I somehow got to the line I had laid a few days before, beyond the restriction at 82 meters (270 ft). Somehow I followed it until I got to the restriction. I don’t know how I knew I had to remove the camera and stage bottle to pass. I was so narked that even out of air I dumped a full tank. (Ironically the line that nearly killed me, saved my life.) I ascended inside the crack, that’s why the emergency 60 meter bottle wasn’t there. It was in Sinkhole B. I had accidentally made a deep connection.

I remember saying to myself: if I escape this one I’ll write a letter to UWATEC telling them they have the greatest dive computer in the world. The 9 meter (30ft) stop lasted 56 minutes, the 6 meter (20 ft) stop 70, and the 3 meter (10 ft) stop nearly 180 minutes. Hypothermia wasn’t a problem. The water at Mysterious lagoon is 25 to 26 degrees Celsius and the thick Northern Diver Semi Dry suit I was wearing was very warm. I barely felt any cold. The total runtime of the dive was 429 minutes. Still having some 30 minutes to go at the 3 meter stop, it was dark, and people started flashing lights to me. They were trying to show me something but I couldn’t see. I thought: it is a snake or an alligator. After what I’ve passed I’m not going to be afraid of anything. I surfaced after the computers cleared. It was an alligator. I was very happy that I hadn’t had DCS symptoms still in the water but now I didn’t know what could happen. I felt good. I was put on free flow oxygen from an emergency kit. That was all we had. I told everybody that I felt very embarrassed for being such a foolish doing the dives that I was doing. But also I was very happy to be alive. After half an hour we felt it was safe to climb the rock path and go home. I even drove back to the city.

I had, over the time, made a good friendship with Cida the owner of Mimoso Farm. We would always stay at her farm, and like a mother, would get worried with us. When we got back to the city of Bonito we phoned the farm to tell Cida that everything was OK and that we had just stayed a little longer in the water playing with an alligator that had appeared (we lied). We didn’t tell anybody the story for sometime because we didn’t want to make a big fuss about it. Actually we were making a secret about all the deep dives because we didn’t want to promote it. When people got to know about the 121 meter dive, some divers started to come to dive deep there and have trouble. We decided to stay a few more hours in the city to see if DCS symptoms appeared. At least there was a hospital in the city. Later on I went to the farm.

The computers displayed a 68 hours desaturation time and 64 hours on ATN mode. I didn’t write to UWATEC but in case UWATEC is reading this, hey you guys, you’ve got the greatest dive computer in the world! I later discovered that water had gone inside my doubles.

Cida is smart and got suspicious about what had happened. She later told me that, that day when I left the farm to go diving, I forgot to tell her goodbye as usual. She then started to have a bad feeling about me. Eventually the feeling got so bad that she stopped what she was doing and went to this special place she has by the woods for praying and prayed for me. She had a feeling I was going to die. Eventually I told her what had happened. I now never leave the farm, to go diving, if I don’t tell her goodbye and always ask if she has a bad feeling.

Even though I had nearly died, I didn’t get a trauma or loose confidence in my diving abilities. I had just become wiser. I knew then that would not make extreme deep air dives anymore. Four days later, the computers had cleared and we went back to recover the safety bottle we had left at 60 meters (200 ft). The visibility had deteriorated due to rainfall. The diving season in the lagoon was ending.

The accident strongly reassured me what I already knew: I had to get trained in mixed gas diving. I was reading all I could about the subject and already was diving on mix on the computer with the ProPlanner program but I only would start doing it after formal training. My last formal diving lessons had been in 1977 at age 16. Having no internationally recognized C-card I decided to enroll in an Advanced Open Water Class in 1991 from a dive store in São Paulo which taught PADI. It was a joke. I had to look outside of Brazil to seek instruction in technical diving. The best place in the world is, of course, Florida.

I was privileged. In late March 1996 the airplane lands in Miami International Airport. I was going to be trained by the best: Tom Mount. He was fabulous! I learned and I learned and I learned. He corrected me in many, many things. He yelled at me underwater many, many times (correcting problems as they occurred). Boy, can you hear him underwater! But I loved all of it. We dove at Ginnie Springs, at Peacock, at Madison, at Eagles Nest, the wrecks out of Ft. Lauderdale and Pompano. I also had the privilege of spending a week aboard the Ocean Explorer on trip to the Bahamas Blue Holes with Tom. We did wall dives and dove the blue holes. It was great! I also had the opportunity to meet diving legends such as Jim Lockwood, Larry Green, John Zumrick. Of course, Patti Mount was terrific also. And so were her dogs, Ninja and Zeus (IANTD’s Mascot Rottweillers). After 5 weeks of intensive training, I went back to Brazil with all the C-cards I could want: Trimix, Trimix Gas Blender, Technical EANx, Advanced Deep Air, EANx Cave, and Advanced Cave Diver.

By June, I finally had my modest mixing facilities working. Air Liquide was supplying the Helium and Oxygen. On June 2, I made my first Trimix dive in Brazil in Paraibuna Dam reaching a depth of 84 meters. It was probably the first sport Trimix dive in Brazil. The following weekend I did another. I felt ready to go back to Mysterious Lagoon.

I believed the cave should go to at least 150 meters deep so I planned a dive to that depth. After many, many runs in the ProPlanner program, I settled with the following profile for the 150 meter dive: 50 meters for 3 minutes on air, 90 meters for 2 min on Trimix 8/62, 110 meters for 1 minute on Trimix 8/62, 150 meters for 9 minutes on Trimix 8/62 (at this point runtime is 15 minutes), 90 meters for 1 minute on Trimix 14/33 and 70 meters for 1 minute on Trimix 14/33. Decompression was with air starting at 57 meters, Nitrox 32 at 36 meters, Nitrox 50 at 18 meters, Nitrox 75 at 9 meters and oxygen at 3 meters. I used a safety factor of 25% and atmospheric pressure of 970 millibars. This kept the CNS at 95%. I had contingency profiles for +2 and +4 minutes and for 155, 160 and 165 meters.

The equipment was configured the following way: The double OMS 121s were filled with Trimix 8/62 @ 250 bars; I carried with me as a stage bottle, on my left side, one OMS 121 with Trimix 14/33 @ 250 bars. My primary superwings bladder was filled from the stage bottle, the back-up inflator from my doubles. I filled my Northern Diver dry suit from a 3 liter bottle filled with air @ 230 bars which I attached to the right side of my doubles. Having read about Sheck Exley’s tragic accident, I wanted to make sure I had a surplus of gas to ascend, and thus I also decided on three independent sources of buoyancy. The air travel gas for the first 3 minutes of the dive was breathed from a 30 cu. ft. aluminum pony bottle which I clipped to the guide line at 50 meters. We had prepared a Deco/Descent line with a buoy (an inner tube) where we staged the air bottle at 60 meters (Genesis 100), Nitrox 32 bottle at 39 meters (OMS 46), Nitrox 50 bottle at 21 meters (OMS 46) and Nitrox 75 bottle at 12 meters (OMS 85), (they were all staged one stop deeper than I would need them so I would have time to sort out any problem with them). The oxygen bottle (OMS 85) was positioned on the lake bank at 6 meters. We also had an extra oxygen bottle (OMS 112) and Nitrox 80 bottle (OMS 112) and several air bottles. I did not carry my Dive Rite light because I was afraid of crushing the battery pack (I was waiting for the new ones) and so instead I carried 5 lights helmet mounted (4 Uks and one Scubapro). I dove all 5 of them on (as Sheck Exley used to do), and one spare in my dry suit pocket (UK).

The descent was carried out just as planned but unfortunately visibility was quite bad, lots of percolation, probably from the preparation of the deco line by support divers just before my dive and tourist divers that had dived shortly before we arrived. I couldn’t see much better than 5 or 6 meters. But it was still diveable. I started following the deco line but at one point it crossed the guide line so I started following the guide line which I knew would take me to 121 meters. At 50 meters I clipped the travel air bottle to the guide line and kept going deeper at a speed no faster than 20 meters/minute, breathing from my doubles. A couple of times during my descent I check to see that my back-up BC inflator is working. At 110 meters the Odin started vibrating on inhalation but stopped after 3 breaths. At 121 meters I tied new line from my primary reel and started swimming in the direction I thought the cave would end. Visibility was bad here also but with helium I could see much clearer and see that the cave wasn’t as big as I thought it was. I swam slowly with a descent angle of about 30 degrees from horizontal. Even though I had planned a bottom time of 15 minutes I wanted to begin my ascent with 13 minutes and so wanted to begin my tie-off at 10 minutes. I kept going checking my depth and time and gas pressure but could not see a good tie-off. Finally, I saw what appeared as a reasonable point, I looped the line twice, made the cut and tied off. I had tied to a projection on a vertical wall, right at the top of what appears to be the entrance of a circular, horizontal tunnel about 5 meters wide. It was pitch black and I could see no bottom. I was 151 meters (500 ft) deep as measured on both my digital depth gauges. The SOS helium depth gauge was reading way off the scale. At 13 minutes runtime I started up slowly attaching line arrows to the line and taking a look around but visibility wasn’t helping. At 102 meters, I sighted at the slope, some 2 meters from me, an aluminum 80 bottle which had been lost a couple of months before. It was light so I brought it with me. At 90 meters I stopped to make the switch to Trimix 14/33 and then resumed ascent and safety stop at 70 meters. Finally I could see the air bottle hanging from the end of the deco line and the lights of Roger, one of my support divers, a few meters above. I wanted to hand him the lost bottle but he wouldn’t descend so I tied it to the deco line and picked up the air bottle and ascended to 57 meters (190 ft) and started breathing from it. I check my depth and found myself at 48 meters and light! I must have been narked on the switch, I thought! I let go of the deco line, dump gas from the BC and descend following the cave wall. I stop at 54 meters and decided to switch to my first contingency deco (+2 bottom time) because of the ceiling violation. This gave me a couple of minutes at 54 meters before resuming ascent. I start searching for the deco line (the visibility was worse) but I could only find the guide line so I ascend following it. At 42 meters I get worried for my next deco bottle, I could not see the deco line and no support diver around, so I started a search pattern with my safety reel. Shortly, Roger appears and points me to the deco line and bottle. I let go of my safety reel and go for the other line. I pick up the Nitrox 32 bottle and resume my ascent. The rest of deco went on smoothly. What had happened (which luckily I hadn’t noticed) was that a BC had been attached inflated to the deco line between the air and Nitrox 32 bottles (to bear some of the weight from the deco line). When I picked up the air bottle it pulled me up and later all the other deco bottles in a big mess. I hadn’t seen the BC because I had switched descent lines on the way down. Luckily the support divers cleared the mess before I arrived at the Nitrox 32 stops.

All six lights survived and I used 145 bars of gas from my doubles. More than I expected. Mistakes had happened. We had to improve the system.

In August we were back for one whole month of diving in the Bonito area. This time we had all the helium and oxygen we could want which Air Liquide delivered to Mimoso Farm for us. We explored Bee’s Hole spring and Formoso Spring and then we started going to Mysterious Lagoon. On the first day we dedicated to fixing the deco line. We used 2 inner tubes and two lines for redundancy. We also had 2 deco tanks each, of 4 different sizes oxygen service rated. We dedicated each size for one Nitrox mix to help avoid confusion (besides regular procedures). On the OMS 46 we used Nitrox 32, on the OMS 85 Nitrox 50, on the Dive Rite 95 Nitrox 75 and the OMS 112 pure oxygen. These were the deco gases we had used on the 151 meter dive, we were using on the spring dives and was working, so we decided to stick with it (what works, works). We changed the placing of the bottles though. We hanged the Nitrox 32 bottles from the deco line, the Nitrox 50 bottles we hung from the log at 18 meters, the Nitrox 75 bottles stayed on the floor between Sinkhole A and B, and the oxygen bottles on a log close to the entrance to the water. Also, instead of dropping with an air pony bottle to 50 meters, I dropped with the air deco tank to 60 meters. At this point I would clip it to the line. We were also drinking fluids during deco. We would hydrate with Gatorade and water, and drink high carbohydrate drinks such as Carb Xcelerator and Mighty1.

The next day we returned. On this day I decided to take Matheus, a dive buddy that was diving with me for the last several months, on his first Trimix dive. The plan called to explore the tunnel Roger and I had began exploring on an air dive, in Sinkhole B, in the 80 meter range. We prepared Trimix 10.5/50 for the dive. When we got to the depth range I looked around but could not find the tunnel. We tested some spots, looked deeper but nothing. We ascended. We had gone to 102 meters and Matheus told me he felt like diving air to 20 meters.

Two days later was the turn for Roger to go Trimix. Roger was sure I had missed the tunnel and said that he could find it. We used the same mixes and deco profile. It’s funny how different things are with helium. Roger did not find it. What we thought was a tunnel that had potential to go on was of little importance when you see it with a clear head. Interesting to note that, on these 2 dives, when I made the switch back to air at 60 meters I clearly felt the narcosis coming by means of lightheadedness. Unfortunately, after the dive, when Roger was going up the rock path with his doubles on his back, he ruptured his right calf muscle bad. You can see how good our decompression model was (or I thought it was): after the dive we had to climb the rock path with our doubles on the back, and we weren’t getting bent. We did rest before doing so and breathed oxygen on the surface.

Two days later I returned to make a solo dive. The plan was to go all the way down to 151 meters to check the tie off and have a good look around. The water was much better and I received a light from Arnold Jackson, a Meteor 5, which he told me was good to 1,000 feet (300 meters). It is a small light perfect for these short dives which I had tested on the previous 2 dives and had a very good beam. The profile had just a few changes from the other one: I would go on air until 60 meters at 4 minutes runtime, switch to Trimix 8/62, 121 meters at 7 minutes runtime, 155 meters at 16 minutes, 90 meters switch to Trimix 14/33 with 21 minutes, 75 meters with 23 minutes runtime (a one minute safety stop). My first deco stop would be at 63 meters still on Trimix 14/33 and I would switch to air at 60 meters. All other switches like on the other dive. Still computed using the ProPlanner with 25% safety factor. During descent, at a depth of about 100/110 meters I felt a little narcosis which went away as I went deeper. I could see much better this time. I got to the end of the line and shined around the light. I dropped down a few meters to have a better look (I went to 154 meters). I was in a vertical fissure, tall, about 5 meters wide until the depth of 151 meters where I have the tie off. Below this there is an overhang and the fissure widens another 3 meters. Visibility was about 25 meters (80 ft). I would shine the light on the walls and follow the beam down until I lost sight. The fissure was some 30 to 40 meters long getting tight at both ends. I could see both ends from where I was, but could see no bottom. The tie off seemed to be at about the middle of the place. On the other dive, I had carried two pressure gauges for my doubles in case one got stuck by the pressure. This time I thought it wouldn’t be necessary. The needle got stuck at 210 bars.

Realizing the cave went deeper than I thought I decided to go back there and plumb the depth leaving the line there as a future descent line. I tied a 2kg weight to the end of a line in a reel (my favorite reel: an enclosed aluminum frame Dive Rite explorer reel - also a favorite of Sheck’s) which contained 305 meters (1,000 ft) of line. I decided to increase my helium content to test a mix I would use if I did a future deeper dive. I prepared Trimix 7/67 for my doubles. All other gases were the same. I also wore a thicker drysuit underwear which I would use on a possible deeper and consequently longer dive. I also increased the safety factor on the Proplanner to 30%. I drilled a hole on the lens of the pressure gauge that I was using and carried another one of different model. Before reaching 100 meters (330 ft) the light head flooded. After the dive I saw that the battery case had flooded also. But it still worked. With more helium I felt even better at 151 meters. I proceeded dropping the weight. I was working with the reel when I felt a heat wave around my shoulders. I thought it could be the underwear I was using. It went away. I had a knot at every 5 meters and one tape mark every 50.

Later at the surface I confirmed 70 meters (245 ft) of line. The cave goes to 220 meters (730 feet) at least.

I tied the line and ascended. When I was doing my 21 meter stop I realized I had pain in my left shoulder. At first I thought I had just strained the shoulder while changing deco tanks but soon I realized that it was DCS. I thought that it could have something to do with the heat I felt on the bottom. I’m still not sure what that heat was. I thought of what to do. Deco gas was not a problem. I had 2 tanks of each deco mix with plenty of spare in each one. I decided to ascend normally to 18 meters where I would change to Nitrox 50 and with more oxygen maybe I would get better. I got better. By the time I was at 9 meters on Nitrox 75 I was fine. But when I ascended to 6 meters I instantly felt the shoulder again, with the pain this time going all the way to the elbow. The pain wasn’t much, it felt like a strained muscle. My deco at this stop was on Nitrox 75 also. I remained at this depth and as time passed I would become better. When my time was through I didn’t feel pain anymore. I then decided to make my 3 meter (10 ft) oxygen stop at 6. And so I stayed the 88 minutes on pure oxygen at 6 meters (20 ft). I didn’t even take air breaks. When the time arrived I ascended very slowly to the surface at a rate of 1 meter per minute. Reaching the surface I felt the left arm a little funny for a short while. I continued to breathe oxygen for 30 minutes at the surface. Luckily this day, Roger brought a sherpa to carry my doubles up the rock path. (Even with a torn leg muscle Roger would come along to watch.) I’ll never forget how the knees of the sherpa shook when he stood up wearing the doubles.

As I write this, I’m thinking about what I’m going to do to continue the exploration. I have to change for the better a few things. The first thing will be the decompression model.

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