Cave Diving, Cave Exploration and Cave Mapping in Yucatan, Mexico
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Category — Cave Diving

Sometimes You Get the Bull, Sometimes the Bull Gets You.

Last week I wrote about an awesome cave dive to The Wakulla Room at The Pit.  Well, three days later, Saturday, I returned to make another try.

Over the last two weeks, I also wrote about some oxygen sensor trouble, trouble might be overstating the issue.  My 02 sensors had come to the end of their lives and needed replacement.  Unfortunately, after many hours of preparation for my dive on Saturday including staging all my gear in the water and starting my dive, I experienced another sensor failure, or sensor abnormality.

To recount the chain of events, on Saturday, 1/17/09, I went to Vaca Ha to do some cave diving on the unit.  The night before as I prepared my Megalodon, I discovered the number 2 sensor was dead, no voltage.  I didn’t think anything of it, the sensor was old and I hadn’t fired up the unit in three months.  I replaced the sensor with a new one dated July 2008, calibrated the unit and dived it.  During the dive at Vaca Ha, the number three sensor became current limited.  It wasn’t a big problem; I took the appropriate steps and exited the cave.  In preparation for my Pit dive on Wednesday, 1/21/09, I replaced the number three sensor with a new one dated March 2007.  That sensor was pretty old, but I wanted to give it a go.  Maybe it only lasts 6 months, maybe it lasts a year.  It was vacuum packed from the factory.  I calibrated the unit and went for a dive at The Pit.

During my 2 plus hours of deco I noticed the number 2 cell started to read a little lower than the other two sensors.  I checked to see if was current limited and I flushed, both checked out.  I didn’t think much of it. I assumed that the cell had come out of calibration as it baked in during the dive.  I figured, I could recalibrate the unit and all would be well.  The number one and number three sensors agreed.  Since I calibrate before every dive, it would be taken care of in my next pre-dive.

And that brings us to Saturday, 1/24/09.  I had another dive scheduled at The Pit.  Again, the setup and gearing up process went very smoothly.  I was super relaxed and ready for an awesome dive.  I finished my in water meditation and dropped down the deco line to check my staged tanks.  At the surface I had a PO2 of .4.  At the 20ft station I stopped and gave my gear the “In Water Two’s Check.”  My PO2 looked fine.  But for some reason, I decided to watch my primary handset as I descended.  This is not something I normally do, usually I check the handset and my HUD periodically to confirm the PO2, but I don’t watch it.

As I approached the 70ft station to check on my 50%, my number two sensor spiked to 1.97.  The other two sensors were in range at 1.0.  I had been adding diluent (7/71) on the way down.  I stopped and hovered staring at the handset trying to figure out what I was looking at.  I watched the PO2 fall on the number two cell from 1.97 to .8, while the other two sensors held steady at 1.0.

At this point I made a mistake; I didn’t flush the unit and put a known gas in the loop.  I just stared at the numbers trying to figure out if I should go for a dive.  Luckily on at least two separate occasions in the past week, I flushed the loop instinctually.  This time due to some mental twist, it never even crossed my mind. I think because it was so near the beginning of the dive and I thought I knew what should be in the loop.  The truth is I had no idea what was in the loop!  I wrongly assumed that I started the dive at .4, maybe I started the dive closer to 1.0.  I really didn’t know at that point, and what is worse is I didn’t know that I didn’t know.  I thought I knew.

After less then 1 minute, I decided to call the dive.  I couldn’t see going for a 4 hour 350ft cave dive with a unit that may or may not be broken.  I decided that when I surfaced, I would replace the number two cell again and try and go for another dive.

When I surfaced four minutes later, I hoisted the unit out of the water and changed the number two sensor with a brand new one.  I fired the unit up to calibrate it and the brand new sensor read 9.4mv.  I stared at it for a minute and realized, I couldn’t remember the proper range for an oxygen sensor.  My sensors had always started above 10mv, and that was my mental low limit.  I asked another CCR diver, Victor an Evolution diver, and he told me 8-13mv was the acceptable range, though I wasn’t sure if that same range applied to the R-22D sensors.  Later, I found out that the sensor was in range.

I decided against diving that day.  It was unfortunate that I couldn’t remember the proper range because I would have been able to continue my diving.  It amazes me how the smallest issue can sometimes put a dead stop to something that took hours and hours to prepare for.  It was a case of not being sure of a fundamental piece of information and paying the price.  In any event, I had hit my limit for the day.  Jorge and I packed up the gear, waved to Santiago and Victor and headed back to Playa for an afternoon on the beach.

The next day I called Patrick Widmann and Andrew Driver to discuss the sensor issue.  The very first thing they both did was give me a good flubbing for not flushing the unit.  The lesson is, know what you are breathing and don’t assume.  It was a good reminder that at any point in the dive, I may need to flush the unit to determine what gas is in it.  It may save my life.  As a result of my discussions, the sensor that spiked has been pulled from service. I am going to take it with me to Florida and put it on a cell checker.   The 9.4mv sensor is going to stay for now; however, I am going to watch it closely.  The bull got me.

January 28, 2009   4 Comments

Getting Bent, How could this happen?

Mhhh…I wish I could entitle this one: “How Not to Get Bent” but unfortunately, that is not what this article is about. I did get bent and this article is just one way for me to analyze what happened and try to find some clues on what I can do different next time.

Most of my personal deep diving experience comes from mixed gas diving in the Egyptian Red Sea. The workload before the dive was minimal since we used a boat to reach the dive site. I usually sat down at the end of the platform with all my stage tanks at arms length. The dive itself was mostly cruising a long a reef wall or wreck at depth, sometimes for pleasure and sometimes for collecting data. Most of the dives were easy swimming since elevating your breathing at depth using Open Circuit Scuba is not really something you want to do. Occasionally, heavy currents made it difficult to hold precise deco stops or forced me to hang on a shot line like a flag in a heavy wind.  Profiles were square shaped sometimes with a single bottom depth and ascent, sometimes a multilevel dive going from deck to deck of a shipwreck for example. Bottom times where typically limited by gas volume and my RMV. Since my resources were very limited in Egypt (80cf tanks only) and I had decided to never make a dive with less then 10min bottom time my depth was automatically limited to about 120m (400ft).

At first I used GAP and later Z-Planner for my custom cut tables.  When I look back on those dives them seem somewhat aggressive, not by choice but by lack of experience and knowledge.  However, I can’t really recall a single time when I felt different after a dive then at the beginning of the dive. Usually, I felt even better because I had spent some time breathing O2.

Doing deep cave dives with extended bottom times requiring long horizontal distances turned out to be way different from doing them in the ocean. These circumstances often force us to do things which can have a very negative impact on our decompression, such as:

  1. Strenuous work before the dive, which includes getting to the site, setting up etc
  2. Strenuous work during the dive, meaning traveling with bigger amounts of equipment long horizontal distances as fast/efficient as possible.
  3. Possible ups and downs as our profile is dictated by the cave which can lead to bounce dives and therefore a higher risk of DCS.
  4. Extended bottom times leading to hours of in water decompression.
  5. Strenuous work post dive, which includes getting all your gear back together and leaving the dive site.

As I reported in the article Three More Trips to The Pit, I believe that our three days at The Pit and my inability to listen to myself, contributed to my accident. Our analysis of the execution of the dive didn’t reveal any of the standard causes, there was no: rapid ascent, dehydration, violation of decompression profile, or ceiling violations.   From an execution perspective, the dive went very smoothly and according plan until the first symptom manifested itself.

Therefore, I have to look for other possibilities to understand the possible cause (if there is such a thing) for my accident or at least identify the contributing factors. Looking at the three days, I believe that I have found a pattern that gradually resulted in me lying in a recompression chamber.  The pattern was driven by the 5 aforementioned points as well as by ego and commercial interests.

Our objectives for the first day were to install a system for evacuating an unconscious diver and execute a dive to Wakulla Room.  During the dive I would fine tune new equipment and bailout at depth to check RMV under realistic circumstances. It took us more time, effort, concentration, work, etc. to install the system then anticipated, therefore we called the dive. For some unexplainable reason, I felt that I lost an opportunity and was behind schedule.  I felt slightly defeated when I left The Pit.

Three days later, we returned with the goal of perfecting the system and executing the first dive of the project. AGAIN, it took way more time, effort, etc. then planned to rig the lift system, however this time I didn’t call the dive. Why? I even thought about it.

I usually tell my students during their training that if they think about calling a dive, the dive is already called and they simply have to inform their team. I didn’t call the dive because I wanted to dive, because of all the effort I had put in, because I had already “lost” one day there, because other people were there to support my dive, because I wanted to know if everything works so I could make further plans, because I have to get this done, because I need to know if my configuration is better, because, because, because a thousand different reasons of which not one has any value compared to the outcome.

Looking back it is all so obvious and clear.  However, it wasn’t back then, I thought I would be just fine. My Ego needed adjustment and it got it!

We entered the water super late; this threw my focus off target, instead of relaxing and visualizing the dive, I focused on the late start.  I did my bailout exercise and finished my dive running a VPM B algorithm which I padded by about 20 minutes divided on the last stops to account for the pre-dive work as well as the workload and higher breathing rate during my fast exit. When I surfaced felt a slight pain in my left shoulder and the right ankle which I explained by the pre-dive work (lowering the tanks with my left arm), heavy kicking on the way out swimming at 60ft a minute in full gear with bailout tanks and the probability of a very minor Type 1 DCS hit. The pain disappeared in less then 10 minutes and I had no other symptoms.

Usually at the end of the dive we rest and eat on the platform, close to the water, for at least 2 hours to give our bodies time to recover before climbing up and evacuating the gear.  However, this time we omitted the rest period because it was getting dark which would have made the drive out more difficult and increased the risk to the vehicles. So, I climbed up and helped the support diver hoist the equipment out as fast as possible.

On the way back to Playa del Carmen, I got a phone call from Alain who happily announced that he had taken the next day off to support us. “Great!” I thought.  Since we had agreed to only dive there with support, every member of our support team is a working dive instructor with very limited time, and with the high season coming in fast, I feared it would be impossible to get enough people together. Maybe that is the reason I felt so pressured to dive.

Back in Playa, we went to Protec to blend for the next day and after a lot of work I finally arrived home at 22:00h. When I cut tables for the following day, I decide to go with the more conservative VPM B/E algorithm.  I took this step to add conservatism in consideration of the pain, all the work and two days of back to back deep diving.  The change to VPM B/E gave me 40 minutes more decompression then the previous dive, Pit Revisited, which had the same profile and longer bottom time.  I considered this more then an ample amount of decompression time.

The next morning, we got out of Playa a little late.  And as Hans was setting up his gear he had an equipment failure and called his dive.  I started my dive alone and felt great.  I found the alternate line into Jills Chamber and was super excited.  The dive was going really smoothly until I experienced a strong pain in my left shoulder on the 12m (40ft) stop while moving my arms. (The hyperbaric physician stated later that excess motion could have triggered bubble formation). Within minutes, the pain pretty much disappeared and so I went through the rest of my decompression padding my stops further due to the unexplained pain.

As I ascended through the last 3m (9ft) the pain in my left shoulder returned and I got a new pain in my both my ankles, the pain was significant. As I contemplated what to do I stayed on O2 breathing from the loop.  After 10-15 minutes, I hauled myself up on the platform doffed my gear and started breathing Open Circuit O2.  I stayed on the O2 until I decided that it wasn’t changing any of my symptoms.  Once off the O2 I started to feel better and better and after 30minutes I was free of pain or any other sign or symptom of DCS.  At this point, I was a bit confused and I scanned my body rigorously for any remote signs. We left the jungle and I felt great! First, my dive was awesome.  Second, I thought I had very closely escaped a chamber ride…Boy was I wrong.

After dropping people and gear I came home and since it was late I ate something and went to bed, still without pain or any other symptom.   The next day I woke up with sore muscles in my left shoulder. Nothing unusual after challenging day in the jungle, however, given the episode I was worried and cautious. As the day passed the pain didn’t change but I had no other symptoms which drove me mad. Here is what I thought,

“If I go to the chamber and tell them the kind of diving I did, they will put me in no matter what and I will not be allowed to dive for at least 6 weeks. Given that diving is my only income and that in the past 6 years the longest brake I took was about 3 weeks that thought was unbearable. It did not help that my work calendar was filled with bookings.”

So, I decided to breathe oxygen to see if that would make any difference, which it didn’t.  Next, a friend came over, who is working a hyperbaric chamber operator, to give me a neurological exam, which came out totally ok. However, I was still very unsure what to do. After some talking, I decided to go to the chamber and see the physician. He gave me the same exam which came out clean, again.  However, as anticipated he sent me to the chamber for a table 6 treatment.

My shoulder pain didn’t change during the treatment, however my right ankle started to hurt on decent and then stopped. Five hours later I exited the chamber in the same condition I entered, except I was more tired and my lungs were burned. The next day I returned with the same issues and so I went back in for a table 5 treatment which I exited unchanged again.  After 5 treatments and no changes they switched the plan to table 9 and I did two more treatments to a total of 7. The last two days I had some relief in the shoulder in the evenings but the pain pretty much came and went and alternated between my ankle and the shoulder.

It was a very difficult time with a lot of emotional episodes. Blaming God and the world for what happened to me and questioning what went wrong over and over again with endless discussions and the opinions of every diver that crossed my path. (Some of which where helpful).

After that my treatment was suspended due to the fact that it seemed not to change anything. I was prescribed anti-inflammatory medication for two weeks and another doctor visit in two weeks. After 5 Days on medication the pain started to fade and now it is sometimes on, sometimes off, sometimes strong, sometimes week. But generally it seems to fade.

I asked the question, “When can I return to diving?” And no one knows. Five different doctors give me 6 different answers ranging from 5 days after pain dissolved up to 3 months. It continues to be a difficult time, I have many questions and there is nobody there to answers them.

Summing up, I think my accident (if you can call it that way) was an accumulation of many things. I believe that the mix of hard work, repetitive long deep dives,  pre-existing injuries caused by the dive the day before and all the other stuff contributed to situation I find myself right now.  Do I regret it? Yes, of course. Will I stop this kind of diving? Of course not! But I definitely learned a lesson or 7.

Safe Diving,
Patrick

I want to thank DAN and the local chamber for doing an excellent job, Hans, Alain, Matt, Steve, Nando, Etienne, Alex, Santiago, Maura, Victor, Allie, and many more for their moral support. I also want to apologize to my family and my girlfriend for putting them through this.

December 30, 2008   9 Comments

Exploration of Sweeden’s Longest Under Water Cave System

Happy Thanksgiving to all my U.S. readers.  I would like to give thanks for the 75’F weather, warm water and miles of beautiful cave we have here in Mexico.  And over course, all of the other wonderful blessings I have in my life, like my family, friends, dog and the good health of all.

This morning I was checking the relevant sources and I came upon a link to a video about the exploration of the longest under water cave system in Sweden.  That unto itself would not be that exciting, however, to execute the exploration they needed snow machines, augers and snow shovels.  Yes, that is right! They ran the expedition in the middle of the Swedish winter.

From their summary, they ran the expedition in the middle of winter because they were exploring a river that siphons under ground and springs a couple of miles later and the winter has the least flow. The cave actually traverses the border between Norway and Sweden.  Whatever their reason, they deserve a huge round of applause because being wet and being cold are very difficult to master, my hat is off to them. The diving looked challenging from the video. Tight sidemount through hard rock and under the ice.

The video is in Swedish but I think it is worth a watch.  So, I give thanks for the easy diving and warm water here on the Yucatan. I have made a couple of ice dives and though beautiful, I am not inclined to make it my primary mode of diving. Keep the videos coming Markus.

The original video can be found here: Expedition Bjurälven from Markus Nord.

November 27, 2008   3 Comments

Surveying While Cave Diving is Difficult

Alain and I spent the day developing a protocol for team tape survey.

On Friday, Alain and I spent the day working on protocols for team tape cave survey.  It was Alain’s first attempt at underwater cave survey and it was my first attempt as part of a team.  When I took my survey class, I learned solo knotted line survey (KLS).  A knotted line survey is the process of using a knotted guideline to measure the data needed for the survey.  For those of you who haven’t surveyed before, here is the simplified process:

  1. Talk to locals and dive a lot.  Eventually a good project will come to mind.  Do some test diving to make sure it is a meaningful project, get permission, and create a plan.  If you need a team to do the work, recruit them and train with them.  And before you start, check your motives.  (This one I got from Matt at Protec).  Ask yourself if the exploration is for your ego? Does it contribute to the cave community?  Are you going to follow through and give back to the community?  How much impact will it have on the cave?  Does the data exist and can I collaborate to minimize risk and impact?  Remember, exploration and survey is a high impact activity and conservation needs to be a close second only to safety.
  2. Sitting at home or in your refrigerator box, use a knotting machine to put knots ever 10ft in some guideline.  This is the really tedious part.  Spool the knotted line onto your reel.  My exploration reel holds about 600ft and my exploration spool holds about 250ft of 18guage twisted nylon line.
  3. Make some survey slates.  A survey slate has a compass and 4 columns for data:   depth, distance, azimuth and comments.  I attached my compass directly to the survey slate.  Trident makes these great slates that are 6in x 8in and have a nice slot for a pencil.  I choose to use a Suunto M3 compass  it has +-2 degrees of accuracy which is the minimum required for the grade survey I am interested in.
  4. Put all the stuff and your teammate in your vehicle and go diving.
  5. Once on site and to the area of cave you want to explore, install some guide line.  When you lay it, make sure you have nice straight level shots and the line isn’t kissing off anything.  Also make sure it isn’t a risk to other divers.  Installing the line is critical; if you do a lousy job here the rest of the job will be very difficult.  My advice is to spend a lot of time looking at existing lines and analyze their placement and their impact on the cave and the dive.  Do they look easy to swim?  Are they safe?  Can they be surveyed?  Then practice putting line into benign situations.  A tight or pristine spot isn’t the place to learn to lay line.  Be prepared!    I have heard some funny stories from Steve about him finding reels and lines that were obviously left by someone who had gotten in over their head.  And remember, take your time and enjoy yourself.  The joy is in the journey.
  6. This is where you have a choice, conditions permitting and gas permitting you can survey the line you just put in on the way out.  Or, if you don’t have the gas or conditions are too nasty, you can exit and survey the new line on another day.  Collecting the data and staying alive are critical to the success of your project.  Drowning with a slate full of survey data is stupid and will curtail any further exploration. We witnessed this recently in Ginnie Springs and it was really sad.  It impacted me and everyone else in the cave diving community, whether they realize it or not.To collect the data you need to record the depth, distance, azimuth and notes at each station.  There is a fine balance between precision and speed and as you practice you will get faster.  I am still pretty slow and I make minor mistakes pretty regularly.  Usually those mistakes are a couple of degrees one way or another, I forget to write a number down such as 16 instead of 163, or I loose count when counting the knots.  Minimize your mistakes by taking your time.  Resurveying kind of sucks and robs you of time to make real progress.And now we have come full circle, it is called a knotted line survey, because you are counting the knots between stations.  When you get to a line segment that doesn’t span two knots you use arm spanning to estimate the remaining lengths.  I know the length of my forearm, tip of finger to tip of finger and tip of finger to the middle of my chest.  Using this method I can get 95% of my data within 1ft of accuracy.
  7. At the end of the dive, immediately record the data from the slate to a notebook.  Slates have a way of loosing data by getting erased or rubbed off.  I have already lost data to this villain, you don’t need too.
  8. When diving is done for the day, I go home and enter the data into Compass.  Compass is a cave mapping program.  If I have GPS coordinates, I place the new survey into Google maps so I can see my relative progress.
  9. Rinse and repeat as necessary.

What I just described is greatly simplified and doesn’t really capture the difficulty or investment required to do a survey project.  Please do not use my instructions to go out and start a survey project.  I suggest that you seek training or mentoring from instructors who are experts in survey/mapping and actually do it themselves.  There are MANY tricks and ways to make it more efficient and I can’t really imagine learning to do it on my own.  Survey is the essence of tasking loading and perceptual narrowing.  I think it could be described as a right brain activity and it can blot out your sense of time and reprioritize things for you.

Moving right along, I learned to do KLS solo so I didn’t really have to deal with any of the complexities of communication or team logistics while surveying.  Recently, Alain and I decided to work on a project together.  The cave has existing line and the line needs to be resurveyed so we could continue our work.  The line is not knotted.  So he and I decided to do a tape measure survey and leave the existing line.  We decided to leave the line to save the impact and time of relining.  Additionally, leaving the line in maintains some of the history of the cave.  I would be sad to see my line taken out, someone placed that line with love and care and it should be respected.  I know I enjoy looking at the arrows and seeing the names and dates.  It gives me a real sense of who was there before me.

A tape survey is when you use a tape measure to measure the line segments instead of knots.  Almost everything else I described is the same.  A tape survey is much more accurate, however it is more difficult.  It requires two people or it requires one person to swim back and fourth repeatedly.  Alain and I selected a 100ft nylon tape measure.

To begin with, Alain and I practiced our survey on dry land.  I set up a circuit and we each set about surveying it solo using KLS.  I walked Alain through the process and we each took the data down.  Then we decided to attempt a tape survey with me as diver one (D1) and Alain as diver two (D2).  We decided that D1 would swim the end of the tape out and fix the guideline as he made progress.  When he reached the next survey station he would signal diver one with a BIG X.  While D1 swam away, D2 would take the depth.  Once D2 received the X, he would take the distance and the azimuth.  After completing the circuit, we switched position and tried it again.  We neglected to create any other signals.  I bet you can foresee what is going to happen. We were happy with our progress so we entered the water.

For Friday’s surveys, Alain was D1 and I was D2.  We planned to survey into the cave and we started at the beginning of the line.  The line at this location starts in 20ft of water and then drops down to 40ft and into halocline. It runs for about 300 feet at that depth and then rises out of the halocline.

Alain and I got the first 2 stations pretty easily.  Then we got into the halocline and I realized that light signals just were not going to work.  I couldn’t tell when he was giving me an X.  And I couldn’t signal to him that I needed to repeat the distance measurement.  Work really slowed down at this point, it was a real trial by fire.  Our communication protocol was short a couple of commands.

The first dive provided many excellent lessons.  I learned that we would need to develop a protocol for communicating through the tape.  I also learned that the process was going to be pretty slow and our SAC rates would be much higher as we settled into the new level of task loading.

On the first dive we collected about 500ft of survey.  It took us 54 minutes surveying and we only penetrated about 10 minutes into the cave.   At 54 minutes we both hit our thirds and had to call the dive.  Our gas consumption was through the roof while surveying.  I can tell you that I was stiff in the water and tense all over.  I could see how I was burning through the gas.  Plus, I was paying attention to surveying and not my breathing.  Luckily, surveying in adds conservatism to gas management.  I survey much slower then I swim, therefore if I use a third surveying in, I should use a 1/6 or less to swim out.

During our surface interval we worked on our protocols for communication.  We developed a system to communicate through the tape.  I also developed signals to ask him to repeat the tape measurement.

For the second dive we swam to the end of the first survey and started surveying.  At this point the cave got much smaller and the condition and placement of the line deteriorated.  The new signals worked out great.  We were a bit more efficient but covered less ground due to the conditions.  The second survey only netted about 300 feet of data.  I was still really stiff, but at least I was aware of it.

When I got home Friday night, I fired up Compass and put the data in.  The stick map started to come together.  I spent a couple of hours and learned how to put the stick map into Google Earth which was a real thrill.  The stick map super imposed on the satellite photos really pumped me up to go back and collect more data.  Overall it was an excellent day with a great dive buddy and friend.  We laughed a lot and got to improve our skills, you really can’t beat that for a Friday.

November 23, 2008   5 Comments

A Tattoo, A DPV and Another Way to Waste Your Employeer’s Time.

It is good to be back in Mexico!  I went back to the states for a week and let me tell you, it was cold cold cold.  I was wearing a hat and a winter jacket; My friends thought I was crazy.  I have to admit, my blood has gotten very thin living in Paradise.  Unfortunately, I didn’t do any diving while I was in the states, however, I did bring back some gear which was sorely needed for us to continue our deep work.   The list of new gear includes new climbing pulleys from Petzl for the lift system, a bunch of caribeaners, tank bands, regulators, hose retainers, mouth pieces and some valves.  I am feeling well stocked now.  I also finished my back tattoo. hans-back-tattoo.jpg

On Friday, I visited my friend Jay at Electric Lotus Tattoo in Boonton, New Jersey and sat for two hours.  This was the easiest sitting yet.  The first two sittings were absolute torture.   Both sittings I was in a terrible spiritual place and exhausted when I arrived.  This time, I was spiritually centered, well feed and relaxed.  I was ready. I only got out of the chair once, about 20 minutes in to look at the first new color in more then a year. From that point on, I just sat there, ate Good & Plenty candy and drank a Coke.  I am super stoked about the art and I am glad I kept my head in the game and finished it.  There were times when I was sure I wasn’t ever going to go back and finish it.

Now on to the DPV portion of the story. After many discussions with Steve Bogaerts and Patrick, I elected to purchase a Silent Submersion N19 DPV. In the end I selected it because it was near my price range, though very expensive, and it was a known quantity. Plus, I hadn’t seen the Tahoe DPV (Scooter) Benchmarks which placed the Cuda as the pack leader for a small technical scooter.  I am still happy with my purchase, although it hasn’t been in the water.  I will have to wait a week for my back to heal before I can get wet.  The suspense is killing me. n19-closed.jpg

And now for a good way to waste some of your Employeer’s time, not that you aren’t right now.  David from Cancun turned me on to the Ejido Jacinto Pat Documentation web site this morning.  He wrote,

If want to see more photos and videos of Nicolai and Gang check this “old site”
http://www.divesitevideos.com/EJPP/
David

There are some interesting dive reports about Nahoch Na Chich and Dos Ojos check it out and let me know what you think!

I hope to get back to diving the first part of next week.    In the mean time, we have an article coming from Patrick about his DCS and another article about me not passing my multi-stage course.

November 12, 2008   1 Comment

Three More Trips to The Pit

Learning to lift an unconscious diver, confirming an alternate route to Jill’s Chamber and a DCS incident.

After a long brake it was time to go back.  This time we started different; with the success of the previous dives in mind we decided to go full scale this time. The main idea was to make the whole project as safe as possible. We quickly understood that being just the two of us would not cut it anymore. Analyzing scenarios including an unconscious diver, a growing number of tanks, and increasingly complex logistics led us to the fact that we would need more support, at least two more divers.

The search was difficult because we were looking for people who like to spend their days off carrying numerous tanks, being eaten by mosquito’s, spending hours out of the water just waiting to later jump in and shuttle tanks around. They also need to understand their role in the team and why we can’t have them fun dive or risk anything even remotely dangerous.  Plus, the idea of trusting your life with somebody else is quiet disturbing. With Hans continually supporting deeper and deeper we needed somebody to fill his spot and somebody out of the water. After many discussions, Hans and I finally called Alain Pocobelli and Etienne Rousseau.  After we explained the criteria for participation they were super stoked and happy to join…awesome.

We all met at Pro Tec for our first meeting.  We discussed protocols, procedures, and set some goals. Specifically, we developed an idea to build a system to lift an unconscious diver from the water up to the trucks, an emergency and evacuation plan, and the parameters for 5 progressive dives the last of which would be a push dive to the end of the line in the Next Generation Tunnel.  We also agreed to document our experiences, procedures and protocols in a manual.  The manual would be used to educate new team members, in the event of an emergency as well as guide our decisions.

The plan for the first day was to setup the unconscious diver system and dive to the Wakulla Room supported by Alain and Etienne. For the support divers, it would be their first opportunity to learn the descent lines and the start of the main line.  For Hans, it would be his first deep mixed gas cave dive.  I would use the opportunity to execute a practice bailout at 300ft while swimming a horizontal distance through the bypass; the primary objective was to confirm my numbers.

As with all complex plans it was bound to change. Constructing a system for lifting a 235lbs (106kilo) diver with equipment 20ft (6m) from the surface of the water and then swinging him on to a platform was more difficult then anticipated. We wanted the system to be simple enough that a single person could operate it in high stress conditions. With limited climbing gear and other resources it seemed almost impossible. Through trial and error it took us some 5 hours to construct and test a nearly working system.  I write, “Nearly” because it still required two people to operate.

After the enormous effort, Hans and I called our dive.  We were exhausted, stressed and it was late in the afternoon.   With the roles reversed, Hans and I played support and cleaned up while Alain and Etienne made a reconnaissance dive.

That evening, I left with a slight feeling of defeat.   It was the first time I went through the effort of blending, putting everything together, waking up early, paying the entrance fee and then not diving.

Three days later I was back at The Pit with a similar plan, this time with Hans and Chris.  Chris is a professional Cave Rescue Expert from Poland. He and I had been diving the week before and when I heard of his profession, I knew I had to get him out there and learn from him.  He quickly came up with 3 different lift systems. Unbelievable!  To our relief, he thought our system wasn’t bad at all; we were just missing one critical improvement that would facilitate single person operation and swinging the body onto the platform.

Unfortunately, rigging and testing took a lot of time and required considerable heavy lifting.  Just like the day before, we finished setting up late.  As I prepared for our dive, I contemplated calling the dive; however I wasn’t able to leave The Pit again without trying my suit inflation system, my new helmet and the bailout plan. Mistake #1.

It is funny how we can feel pressure where there is none. As we prepared for the dive we were feeling time pressure; therefore we decided to shorten the bottom time. Without my normal pre-dive meditation we hurried into the dive. I laid line and Hans staged his intermediate mix.

Cruising through the bacteria cloud at 190ft (57m) I was super happy to finally be back. At the T before the Bypass Hans and I split, he swam through the Bypass at 281ft (85m) and I took the deeper “Main Tunnel” at 305ft (93m). Surprisingly, it is quiet narrow and more difficult to pass.  Two minutes later we met at the second T where the lines join again; it was time to turn the dive and start the bailout drill.

I signaled Hans and bailed out. I chose a bailout gas with a deeper END than I normally use to make it more difficult and more realistic.  To add to the realism, we planned to exit the cave with haste to simulate the highest possible gas consumption due to stress or CO2 poisoning.  For precaution, Hans closely monitored me ready to donate a shallower END bailout gas or I could go back on the loop in the event the Inert Gas Narcosis was too strong.

The first three breathes brought on the strong narcotic effect and it became difficult to focus on my objectives. Complicating the situation was the fact that my weighting in saltwater was neutral with my wing totally deflated. So being off the loop with gas remaining in the counter lungs made buoyancy management more challenging.

Imagine me swimming at full speed while squeezing through the Bypass, switching the set point down to avoid O2 injection, opening the OPV and rolling to get as much gas out of the loop as possible and I was becoming positive, all under the effect of Inert Gas Narcosis…what a blast. I am happy I couldn’t see myself.

By the time I arrived at the turn at 213ft (65m) I had regained composure and everything went “pretty” smoothly from there.

The main goal of simulating a realistic bailout scenario at depth was absolutely accomplished, I learned A LOT.  The old saying: “Slow is smooth and smooth is fast” confirmed itself once more, thanks Steve. I use this line like a thousand times per course, maybe I should listen to myself once in a while.

After the dive, we truncated our normal 2 hour break because it was getting dark. As I climbed out to hoist and load the tanks, I felt a slight pain in my left shoulder and right ankle; it subsided quickly.  However, it was definitely an indication we worked too hard before and during the dive and that we needed more conservatism.

As we loaded the truck, I got a phone call from Alain who had taken off the next day to join us at The Pit. Since support was available and we agreed to not do anymore push dives without support, we felt obliged to dive.  We agreed to dive the next day, mistake #2.

Again, it is funny how we feel pressure where there is none.
We didn’t anticipate that our desire to increase safety by having more support onsite would pressure us into something we knew from the beginning was a bad idea?!?

After blending and prepping the rebreathers, I arrived home at about 2200h. I ate, hydrated and went to bed. The next day we started even earlier to hedge against time pressure. However, we left Playa late because we had to reassemble the CCRs, analyze gases and leak check everything in the pool. Once on site we reinstalled the evacuation system and instructed Alain on the improved version.

For a second day in a row, I was late into the water due to Hans calling his dive because of technical difficulties with his Meg and Alain bruising his leg when he slipped and trapped it between the platform and the rock wall.  Calling the dive crossed my mind, however everything was in place and I felt confident it was safe.  Once the dive started, I was slower then normal as I had to swim all my tanks and stage them.  Mistake #3.

My goal was to explore the other passage into Jill’s Chamber and see if it would be easier to navigate with a scooter then the horrible chimney I passed last time. I hoped to find the origin of the line that was paralleling the main line through Jill’s Chamber into the Next Generation Tunnel. To add conservatism, I selected the VPM B/E algorithm.  I wanted to accommodate for the back-to-back days of deep diving, the strenuous pre-dive work and as a response to the way I felt the day before.

I arrived at the end of Wakulla Room only a minute slower then planned, even though I had to stage all my tanks.  As I swam through the BMB, I started to get a little nervous again, anxious to see the size of the restriction.  Before the T, I crossed sides to get a peak up the restriction. Fortunately, it was a little bigger and did not ascend vertically like the chimney.  It’s slope was more manageable as it ascended to 328ft (100m), instead of 314ft (96m).  There it led to a canyon depicted cave, which headed towards Jill’s Chamber.

After a short distance there is another T. Well actually it is a Jump that is “T”ed into the main line. The main line ends about two body lengths after. So I took the T to the left and further ascended into an even narrower canyon, which further ascends towards Jill’s Chamber.

I was stoked because I was nearly 100% sure that I had found the origin of the paralleling line and passed the chimney. About 1 minute later I was in Jill’s chamber and it was confirmed. It is pretty hard for me to explain my emotions; I felt unbelievably awesome! I think it took me like 30sec to gain control over my euphoria. I was 20min into the dive and I had fulfilled my objectives; it was time to turn.

The way out was relaxed since I did not have to pass upside down through a tight restriction. My decompression obligation was substantial due to the more conservative VPM B/E algorithm. I stopped at every waypoint to keep track of exit times, picked up the tanks and did a couple of short deco stops in between the levels.  Forty-five minutes into the dive I could see the open water in the distance and my Time to Surface was about 160min.

At 131ft (40m) Alain greeted me, took my tanks and left me with one 80cf.  I swam around the huge dome to stay warm and to help the time pass a little bit faster. Even though I was warmer then past dives, I decided that this would be my last long dive at The Pit without a habitat.

When I arrived at 40ft (12m) the dive had been going perfectly and I was very happy.  I swam around and moved my upper body a little bit to warm up and increase blood flow. Suddenly, I felt an unbelievably sharp pain in my left shoulder. At first I was shocked but I was hopeful because I still had almost 2 hours of deco ahead. The pain faded about 15 minutes later; however, I decided to extend all the remaining stops.

When I arrived at 20ft (6m) I extend my 65min stop to 75min. The pain was almost completely gone and I started to surface. At 10ft (3m) I added a stop even though the urge to surface after 4h almost drove me crazy. After 5 min I started a super slow final ascent. Almost immediately upon surfacing the pain in my shoulder returned at full intensity accompanied by pain in both ankles.

I stayed in the water on the loop breathing O2 for 20min contemplating what I should do.  Should I get out of the water or go back down?  Eventually, I decided against going back down because of my body temperature, general physical state and a 100%+ CNS clock.

As soon as I surfaced and didn’t come off the loop, Hans was nearby with an 80cf of O2.  When I decided to exit the water, he helped me strip my gear and I pulled myself up onto the wooden platform. I lay there breathing open circuit O2, hydrating and scanning my body for neurological symptoms. After 30min the intensity of the pain hadn’t changed. I decided it was time to evacuate. I climbed up to the trucks and sat down for a moment.   The pain disappeared and the general fatigue vanished.  Coming off the long period of high PO2 it seemed plausible, but I didn’t trust the situation since something felt strange.

As we left The Pit, I continued to scan myself for pain or neurological symptoms related to DCS. I felt great and honestly a bit relieved. The entire drive back I tried to figure out what happened.  I wanted an explanation for the weird sensations I had at 40ft (12m), on my final ascent and shortly after the dive. Why did I feel that way and what can I do different next time?  Arriving home I felt unchanged: no pain, no extreme fatigue, and no other symptoms. A long day had passed and I was happy to be home and ready for dinner and bed.

I am really happy about our progress and our understanding of the cave.  I am also happy that our team is growing and we are taking a more conservative approach to diving and the project’s logistics.  The project is remains very exciting and we are learning so much from each dive.

Looking back it is easy to identify many of the mistakes.  Many of you will ask why I made them? I can only answer that I am human, this is a learning experience and mistakes are inevitable.  Sometimes the cost for a mistake is small, sometimes it is huge.  Life it seems is a hard teacher, many times you get the test first and the lesson later. There was a time when I read articles like this and said: “Ha, I would never make mistakes like that.” But this was also a time when I didn’t do dives like this.

I want to thank Chris for his invaluable input on our rescue system, Alain and Etienne for supporting us and joining the team and Hans for letting me post on his blog.

Unfortunately, as you may have guessed, I suffered a DCS incident.  I am going to follow this story up with another about the DCS.

This is my story about the Pit and it is to be continued.

Edited By Hans

November 5, 2008   7 Comments

8000 Feet, One Spool and One Total Loop Failure

A traverse from Naharon to Mayan Blue on rebreathers.

This past week has been very busy for Patrick and me.  With the arrival of “Slow Season” here in Playa Del Carmen, we have found more time and more opportunities to get ourselves into some serious dives.  We have made two trips to The Pit and one trip to Sistema Naranjal with our Megalodons.  Luckily, the dives at The Pit were relatively excitement free, other then Patrick reaching the restriction at Jill’s Chamber at 105 meters.  However, the dive at Naranjal was anything but boring.

Patrick had finished up a full cave class at Mayan Blue on Sunday.  Unfortunately, the student didn’t complete the A Tunnel / Death Arrow circuit, so we had to retrieve the remaining gear, one spool.  We decided the only reasonable way to do the clean up dive was to traverse from Cenote Cristal (Cenote Naharon) down to the Death Arrow jump, pick up the spool, and swim back.  The swim from Naharon to Mayan Blue typically takes about 2 hours.  We decided to cut the swim a little short by only going to the end of the Death Arrow passage.

When we were planning our bailout gas, I was worried about having enough.  I hadn’t swum this distance and I wasn’t sure of the depths.  Patrick and I agreed to take 2 Aluminum 80’s each.  We ran some calculations and it was enough to get us out if we needed it.  Patrick’s calculations showed that two 80’s would last him 4 hours at this depth.  My SAC is higher, so I didn’t have same cushion.

When it came time to decide on our gas mixes, I asked Patrick what he was taking?  He told me Air.  And then we got into a discussion about bailout.  He very sternly explained to me that the choice of bailout gas didn’t really matter.  He didn’t believe he would ever have to bailout.  However, if he did he would only be punished with deco time.  He explained that he follows a checklist and is meticulous about assembling his unit.  I told him I was going to take 32% regardless of his feelings on the topic and I was going to drop a tank of O2 in the cavern for good measure.  You really never know when something unexpected is going to happen.  Isn’t that the definition of unexpected?   We agreed, or I decided in my head, I can’t remember, that if someone bailed out, they would get the 32% and the Air would be the gas of last resort.  At this point, Patrick’s attitude really concerned me and I decided that I was going to have a sit down with him, but I was going to wait until after our dive, as to not mess with his head.

Wednesday arrived and we got on our way.  The dive was going according to plan.  We passed the restrictions heading for Mayan Blue.  At the T, I wanted to “drop” a cookie.  As I got my markers out of my pocket, I dropped my safety spool. I reached for the safety and lost control of my buoyancy and started to fall.  I reached for the inflator, but no luck!  I ended up rolling down the windows saving myself from crashing into the mud, but creating some silting.  I could hear Patrick laughing as he watched this comedy of errors.  I finally got my act together, marked the T and proceeded.  I am sure it looked hysterical, you know how things happen in super slow motion, I know I was laughing about it.

We arrived at the spool at 80 minutes.  He retrieved the spool and we rested briefly.  When we finally got going on the return trip I was in the lead.  We were singing into the DSVs and just enjoying the dive.  After about 10 minutes we settled into a decent rhythm and pace.

At about 20 minutes, I saw a quick flash of the light head of me.  I instinctively turned and started to swim to Patrick.  We were about 50feet apart.  It took me a second to process the situation.  What I saw was one of the breathing hoses from the KISS Classic just floating in the water and I saw Patrick deploying a bailout reg.  My first thought was, ‘Oh shit, what do I do?  My bailout regulators are really secured and are not quickly accessible.’  Before I was close enough to help, he got his regulator out.  I arrived and assessed the situation.  The exhale breathing hose had disconnected from the canister.  At Patrick’s request, I reattached the hose.  We thumbed the dive, changed positions and started swimming.  This is when my heart rate finally picked up and I became aware of the gravity of the situation.  This was a real live catastrophic loop failure way back in a cave.  This is the exact type of unexpected situation we train and prepare for.  I knew we had enough gas, but I still got hit with some adrenalin.  I had to stop and think about my breathing and heart rate for a second.  My heart rate really isn’t under my control sometimes.  The base of the brain just reacts.

As we swam, I stayed near to Patrick in case something else went wrong.  I checked my computer and marked the time.  We had 60 minutes of swimming up stream to exit the cave.  Patrick cleaned up his hose routing and attempted to go back on the loop.  As I watched him attempt this, I just kept thinking, “You can’t recover a KISS from a total flood.  Don’t try.”  He found out in short order it was a done deal.  Then I offered him my 32%.  He waved it off, and he started to play with his X1.  Patrick later told me he thought he would be fine on air.  However, a couple of minutes later when we reached the T, he realized he was running out of no stop time and asked me for some 32%.

He asked at the worst time for me.  I was about to pick up my cookie and had too many things going on at once.  I struggled with my tank for a minute and finally told him to start swimming.  It would be easier to make the switch underway instead of hovering.  At this point I made a mistake, I think I was a bit overloaded and my brain was fried.  Instead of doing one thing at a time, I had the tank neck out of the bungee in the left hand.  I reached down to get the cookie with my right.  Now I was swimming with both hands full trying to get my tank completely off.  Ug! What a nightmare!

I finally stopped and stowed the cookie.  Then I passed the tank to Patrick.  He reached down to pull the regulator off the tank and the mouth piece came off!  The irony is that Patrick recently told me it was stupid to put the bungee necklace under the same zip tie as the mouth piece and that the mouth piece would come off at the worst time.  I defended my choice and didn’t change my configuration.  The bungee was wrapped around the tank neck and under the single zip tie.  When he showed me the regulator without the mouth piece, I could hear his voice in my head and I laughed.  I have since changed my configuration for CCR diving.  I removed my 120 degree swivel and the necklace on the bailout regulators.  I want them to be as accessible as possible.  Now, I believe that I will need them at the worst possible time.  He replaced the mouth piece and started to enjoy the joy that is 32% EAN.

Patrick swam off and I struggled with his tank.  This dive taught me my sidemount bungees are too short to be useful in an emergency.  As I struggled with the tank, I swam into the ceiling with my rebreather.  It got a little hung up so I jerked my head down.  I immediately realized my head was way heavy and I was heading for the floor!   A huge rock had broken loose and was on its way to pinning me.  I rolled to the right and the rock fell off my head before I hit the ground.

Again, I laughed.  I couldn’t believe how many things had happened to us on a single dive.  We have been diving for seven months together and all of those dives had been incident free.  A series of walks in the park, including cave dives to 300ffw.  The type of diving that breeds complacency.

I caught up to Patrick and we continued to exit.  We decided to pull our gear.  As I pulled my spool from the jump between Southern Sacbe and Southwestern Sacbe, I created a nasty knot around the main guideline.  I ended up cutting the spool free from the guideline.  It was the last in a row of incidents.  We exited safely with a total run time of 180 minutes.  I estimate the total distance at around 8000 feet.

Patrick and I agreed that we handled all of the situations acceptably.  We did a serious review of the dive and have both made changes to our rigs and attitudes.  As I mentioned, I changed my regulators and I lengthened the sidemount bungee.  Patrick also made some changes to his regulators to ensure they are accessible.  We adjusted our bailout gas attitudes.  And we agreed to take better care to avoid team separation.

Once the stress started to pile on, it made simple tasks like a tank swap more difficult.  A task he and I normally can handle in a minute or less took a couple of minutes.  My overall awareness decreased and we got a good distance apart more then once after the main failure.

I feel it was an excellent dive!  We both returned and no one was hurt.  We tested our abilities as a team, and as individuals in a stressful situation.  We both stayed calm and controlled our breathing.  We reacted instinctively and completed the tasks at hand.  We realized our performance wasn’t perfect but it was acceptable. The whole dive confirmed to me the following idea.  Bailout is for unexpected situations and it does matter.  No matter how bullet proof you might think you are or your procedures, unexpected shit happens and it will happen at the worst time.  And these situations never happen alone, they are always compounded by other events.

Patrick used just over 2000PSI from one Aluminum 80 to exit from 60 minutes into the cave.  I hope you learn a little from this, I know I have learned a lot.

As always, your comments and criticisms are welcome here.  If you want to know more about the incident, leave a comment and one of us will respond.

July 29, 2008   13 Comments