Category — CCR Cave Diving

…The very next day I was back in the water with Yamil and this time we couldn’t finish again as I had another course already booked but we could get another two days done.

Then Ritch came in who I had taught previously during his cave diver course to do some training in deep diving and expand his horizon in cave diving with a basic Sidemount class. As Ritch was already a cave diver his basic skills just needed a little brush up but we were ready to go and introduce new information and skills such as SMB deployment, gas switches, team formation in open water, ascent protocols, and so forth. We did a deep diver and advanced Nitrox combination and so the theory was focused on gear selection, dive planning in regards to decompression, gas volumes, oxygen exposure, emergency procedures and plenty of real life examples. During our dives we saw different environments as we used a Cenote for confined water, a sinkhole for our first dives and then moved over to dives in the ocean. During our dives in the ocean we went down to Xpu-Ha and then drove down a bit south to the deep reefs. After arriving on the bottom I have to admit I was surprised how cool the reef was. Anybody that knows me, knows I am not super keen on ocean diving, but I have to say that I really enjoyed the dives there as it was full of life and colour.

Right after that we were back in the caves (juhu) and our first objective was to built a rig that Ritch would feel comfortable in. Being that Ritch is a bit larger then life it wasn’t quiet that easy but not that hard either, and I think at the end we came to a total price on his rig of like 100usd or smth =) The next two days we were training first in open water to get familiar with the equipment and to understand 3 dimensional diving, fine tuning here and there and working on gas management and emergency procedures the basic game. After that we started with cave diving in passages that he could have passed in backmount but only with serious effort but now in sidemount were manageable with ease. It was cool to see Ritches smile after the dives because he felt so comfortable and free under water as never before with a set of doubles especially since the normal backplate simply doesn’t fit on his back. We even had a day to spare and go for a fun cave dive down in Chan Hol which we both really enjoyed!!!

Ritch in a basic harness with a modified BCD

The days after that we could finally finish Yamils cave training with two last spectacular days in Taj Maha and Xunnan Ha. It was kind of funny since I went from the biggest person I have ever trained (Ritch) right to the smallest one (Yamil). The same way I like to challenge my students during training I like to be challenged myself, and so it was really cool to look for ways to make the two comfortable in the water although they had slight disadvantages due to their seize. At the end of the day the two of them really came around during the course and I was more then happy to sign their certification!!!

Right after that it was my time to be student again, Yipi!!! I had enrolled in a GUE fundamentals class with Fred who I know and respect for some years now. I am constantly trying to evolve as a diver and as a diving instructor and part of that is to take classes myself not only to see again how it feels to be watched and critiqued but also to see how the instructor teaches and relates information. All in all it was a great experience and lots of fun and I am looking forward to do further courses with Fred an hopefully also with Danny and Chris!

At the same time my dear friend and dive partner Hans (with family) was is town and so of course we had to seize the opportunity to go cave diving. He had spent the last couple of days exploring with Mauro while I was teaching and now that I was free the three of us went to Cenote 307 adding some 600ft of line in small unstable but awesome cave!!! The day after that we went down to Dos Pisos for a three hour swim around since neither of the two had been there before. There is really hardly anything better for me then going cave diving with a couple of friends and just enjoy a day out in the nature!

Little Hans

The day after that I was back teaching, finishing Anneleens course that she had started with Nando. We had only the last three days left to go from intro to full cave. Anneleen is a local diving instructor who finally after living here for more than a year gave in and started cave diving. It was fun to watch because she instantly was so fascinated and stunned by the caves that she was still smiling hours after ascending =)))))

Finally the last couple of days I had the great pleasure to dive with Dr. Mel Clark and show her around a little bit which was great. Of course it is always cool to dive with another CCR cave diver especially one that is in the hall of fame!!! We did some really amazing dives and finished with an insane trip from Cenote Dos Palmas to The Pit and back. Some 4h of non stop scootering…I don’t know what was better the dive or finally getting out of the water releasing the pressure in certain areas =)

Mel with a 42 ... without batteries in it though =)

After that I got another two former cave students in, Jojo and Chris from the french part of Swiss. We started of doing a stage, multistage course which was really super fun, since I had to teach in french which always kind of makes me look like a stand up comedian. In the evenings my brain was so much in knots that I started to mix all sorts of languages and simply was not able to communicate anymore. Moments like this always make me think of my polish chemistry teacher in high school, being that chemistry isn’t the easiest subject in the first place, only being able to understand every third word of the teacher doesn’t really help either But they both assured me that I was doing great and that they really understand what I am talking about (yeah right…)! Thanks god hand signals are international!!!

Jojo and Chris still suited up to avoid the bloodsuckers

After that Jojo continued with a Normoxic Trimix class which brought me back again to dive in the ocean. After the confined water session in a cenote we dove out of Xpu-Ha, mostly hanging out at the drop off =) Jojo really enjoyed the training especially the ratio deco which was a new concept to him and as he told me changed completely the way he looks at dive planning now! I am always happy and glad to get such a reaction from a student!

So I hope this little report shows why I didn’t post too much in the last 2 months but I was simply too busy living the dream and going diving every day, hahahah! I hope you enjoyed the post nearly as much as I enjoyed the dives!!!

cheers Patrick

I just come out of a pretty busy run full of teaching and exploring, tiring but fun and now as things slow down a little bit I can take the time to write about it.

When I had finished the basic sidemount course with Wayne I was off on three weeks vacation. First I had planed to travel to Dominican Republic and everything was set until my travel partner had to cancel due to work obligations. I was pretty bummed out about the whole situation but when Mauro asked me to join a project he and Alex where pursuing I forgot about the situation and was looking forward to go and explore with the two.
In the same period of time I also got the second draft version of a sidemount rig I help to design which instantly outdid all my expectations and gave me great motivation to go out and dive again daily. So besides exploring I also dedicated a good amount of time to testing the rig in various different diving environments as well as techniques ranging from wet to dry suit, stages and scooters in backmount and sidemount seized passages.

With Mauro I was exploring in Cenote Balan Ak where Alex had established the relationship with the landowner and out of Cenote Palomita to resurvey and push some lines. A great pleasure to hang out and dive with the two guys who are both so passionate about the exploration there.

After that it was back to work and I started my first course right away with Mark who came in to do a deep/advanced nitrox combo course. A cool start that gave me also the rare possibility to dive in the ocean. After one day in a Cenote for confined water training and another day in the sinkhole Angelita we lost a day to sickness. Having only one day of diving in the ocean left, we couldn’t finish the training but Mark has already booked his return in September where we will not only finish but also integrate the advanced recreational trimix course.

Before the next course I had the great opportunity to help Nadia a cave explorer that lives down in Tulum with her mapping project of Cenote Dos Pisos. It was a super experience, first of all since I had never attempted to produce a large scale cave map (besides stick maps of course) and second it was cool to hang out with her and talk about different projects she is pursuing with her husband Dave in the area as well as some of the history of  the Cenote and the Cave System.

After that I almost instantly went into a CCR cave course with two Germans, Dirk and Thomas who came equipped with an Inspiration and a Megalodon CCR. Dirk had already done his course in Thailand some time ago and already visited Florida and Mexico for cave diving but wanted to sit in and train with his buddy. Dirk was one of my really first advanced nitrox students back when I lived in Egypt and to see him now as a very skilled trimix/cave ccr diver puts a big smile on my face. Thomas being a very experienced trimix ccr instructor himself made for a great team and hard for me to challenge the two.

Thomas and Dirk back from a dive in B Tunnel

The first two days we spent in the open water working on buoyancy, trim and fining techniques as well as looking at the units and trimming them down to minimal seize. We also went through all of the ccr related exercises followed by zero visibility training and touch contact and touch and go procedures.
Third day had us in the cave ready to go and trying the first time all ccr skills while staying horizontal within arms reach of the guideline. We realized quickly that doing those skills in a dark place with limited space while staying perfectly trimed with neutral buoyancy is not a quiet easy thing to do =)
The next five days we were working on many different scenarios including hyper and hypoxia drills, boom scenarios, hypercapnia, long hose gas sharing of bail out, passing restrictions in zero viz, complex navigation, surfacing in zero visibility, solenoid stuck close and open during a cave dive, lost line and lost diver and many combinations of the above.
During the entire course we had lots of fun and a general relaxed atmosphere and shared many stories of diving the cold lakes in europe =)
Both of them came very open minded in the course and with a lot of experience which gave us many interesting topics and point of views to discuss, all in all a great time!

Dirk and Thomas tired but happy!!!

After that Dirk who had brought his own scooter enrolled in a three day basic cave dpv course. We were using Bonex(dirks), Silent Submerge as well as a Divex Cuda during the training to see different performances and characteristics of the models.
First day we were doing theory all morning discussing pros and cons, gas management, emergency procedures, conservation and other topics before driving to Cenote Ponderosa to do our initial training. We were practicing different towing techniques, how to keep neutral bouyancy while driving, touch contact, touch and go and runaway dpv failure which especially on the bonex is an easy scenario due to his master switch.
The next day we were in the cave all day long going through lots of complex exercises involving lost line and lost diver during a dpv dive, computing different RMVs and times which are essential to dive planing, zero visibility drills including picking up gear, dpv failures, time awareness and so forth. Dirk realized very fast that there is more to scootering in a cave then pulling a trigger =)
Last day we implemented all of the previous learned in complex dives in cenote Mayan Blue which turned out to be just amazing! The previous long days payed of and we could use our rebreathers and scooters effectively. We did long dives covering an amazing distance while relaxed sight seeing knowing that at all times even with two catastrophic failures we would still be able to safely exit the cave. Now Dirk must get some more experience using his new favourite tool so that next time we can bring out the long range dpvs and take it to the next level. =)

The next day I went straight over to a OC cave course with Yamil a local diving instructor who had started some time ago but couldn’t finish due to work obligations. Again we were not able to finish his training due to a bad cold that knocked him out after the first two days.
At least that gave me the opportunity to squeeze some days of exploring in and even a fun dive with friends from Utila (Frank and Andy). We were a big group consisting of Dirk, Thomas, Mauro, Frank, Andy and myself and were diving in separate teams in Cenote Muchachos. Dirk and Thomas on CCRs, Mauro sidemount and stage, the Utila gang after finishing their basic sidemount training with Nando in their new rigs and me CCR also and dpv. A great day with 3h+ dive time =)

The following day I welcomed Nick who came in to “upgrade”  from GUE Cave 1 to Technical Cave Diver. We had met before to discuss exactly the expectations that he had in the course and that I had from him as a student. Nick came in as a highly trained, skilled and experienced diver which made my job both very easy and difficult. Easy in a way that he learned extremely fast difficult in a way of bringing him close to the edge of his comfort zone to establish some limits. The main new information and skills we had to cover were navigation, restrictions, deco bottel and stage tank use in the overhead environment and reviewing the stuff he had already learned and all of that on a tight schedule which ment early mornings and late evenings, especially for me as Nick stayed in Puerto Aventuras…
Nick is an avid deep and wreck diver from Australia which made the lunch brakes very entertaining as he shared some insights on the local wreck and cave diving in the land down under. I really hope I will get the chance one day to visit him there and check it out!!!

So that was part one…part two will be up in some days…I hope you enjoy =)

cheers

A little while ago I was teaching a CCR Cave course down in Tulum. Besides the daily driving it was definitely nice to teach in different places than I usually do. To change the air conditioned classroom and PC with the mosquito infested jungle and a white board didn’t appeal to me at first but having the water and breathtaking nature right next to me had definitely its advantages!

My student was Enzo, an Italian Megalodon diver who had already plenty of experience diving CCRs and after having done plenty of deep and wreck dives finally became interested in cave diving. He also managed to combine his training with a relaxed vacation together with is girlfriend in a romantic hide away hotel right on the beach.

The first day we met with all the gear at Cenote Carwash (Aktun Ha) to start of with paperwork, some theory and gear configuration. It was also the first opportunity to chat about different point of views on CCR diving, Bail out Strategies and Dive planning. After agreeing on important points and trimming and streamlining the gear as much as possible it was time for the first splash. Checking if all the gear works and getting comfortable in the configuration and the new environment. Carwash is really a perfect place for that with its easy entrance and exit possibilities. The first session was only focused on buoyancy, trim, and fining techniques to create a stable platform from which we would be able to perform more complex tasks. At 6pm we left the water and it was time to pack up and head home.

Next day we were back in the same place, this time though less talking and more action. The day was split in two water sessions and a brake with some theory and dry line drills. First up we were working on the CCR related skills. Now most divers when they enter the course have a good understanding on the principles of the ccr skills but never tried to do lets say a diluent flush while staying in a horizontal trim and within an arms reach from the guideline. You also cannot lose your depth control while performing the exercise since that would mean crushing into the sediment covered floor or ceiling which could result in loss of visibility and the danger of damaging a vital part of your equipment. So the main goal of this session is to “cave modify” the already learned skills.
In the afternoon we were working on the cave related skills which added new things while still perfecting what was learned before. The exercises are dealing with zero visibility scenarios and are meant as well to teach the student to deal with task loading in stress full situations. Always with the eyes closed to train other senses and the means to navigate underwater in total darkness.

The next day, after some more line drills, we where finally ready, to depart on our first tour in the overhead environment. The first dive is always a demo dive where the student is walked through the pre dive checks and later shown how to use the reel and how to install the guideline. Being second gives the opportunity to observe and focus on buoyancy, trim, and propulsion techniques.
After surfacing and debriefing we stayed in the water to drop back down and run once more through the CCR skills while maintaining our position in regards to the line, the floor, and our team. Most accidents don’t happen because of a single problem but an accumulation. A key element in avoiding accidents is to cut the chain of errors as fast as possible before it gets out of hand.
After hours in the water we left, tired but happy and satisfied!

The fourth day of our training was here and we were off to a dive site south of Tulum which to cave divers is known as Naharon. A very dark but beautiful place just perfect for conducting training dives.
First dive of the day and the first time for Enzo to be the team leader. On the way out we simulated a zero visibility situation and exited using touch contact and touch and go communication. All in all a good success which just confirmed that all the time we had invested training in the open water was not wasted.
On the second dive we ran through some CCR skills, same as the day before, just this time in the cave in darkness. Bailing out gave us the first chance to confirm our calculations with real numbers from a simulated emergency.

After a day brake we were back at the Cenote for some more fun. On the first dive we repeated the bail out scenario and changed donor during the exit and then continued into a zero visibility simulation to further the complexity of the exercises and to simulate worst case scenario.
Second dive we introduced the lost line scenario after practicing it on the surface. Not on the first try but after conducting a systematic search Enzo found the line and I could here his enthusiastic scream into the mouthpiece.

We continued our training in Jardin Del Eden aka Ponderosa so that Enzo would have the opportunity to see a different type of cave. I generally do at least one dive in Tulum when I am teaching around Playa Del Carmen and Vis Versa.
This day we started complex navigation introducing Jumps, Gaps and Ts as well as techniques to negotiate restrictions with and without visibility. To round the whole thing up we had lost diver scenarios and CCR failures.

The last days we were back down in Tulum diving in Zazil Ha and Grand Cenote to further complex navigation, restriction training and completed an entire dive flying the unit manual amongst other things.

All in all a great course, fun time and awesome dives.

After that Enzo also booked some guided CCR cave dives to enjoy the caves without being hassled by an instructor all the time =) and to simply use the learned in real life.

The need to confirm data, inform a dive partner of a problem, to ask questions and to give as well as receive answers is an essential and integral part of diving. Unclear communication can result in distress or even can accumulate into emergency situations. In advanced forms of diving or the overhead environment this need of precise communication is amplified.  Darkness in black water, inside wrecks or caves makes the process and need of communication much more important and can complicate the means of communication.

Underwater communication is more complex in caves or inside wrecks then in open water. Simplicity and ease of understanding are essential. Standard communications have been developed for general communications but if special tasks are to be performed such as cave, reef or wreck survey teams the need to develop specialized communication for specific objectives is imminent. Lights and correct lighting are essential for  talk”.

The need for communication depends on multiple factors. These would include the size of the dive team, the experience levels of each diver, visibility, environmental factors as well as questions related to the specific objective of the dive. Normally, as long as each diver’s light is visible, without erratic movements and the distance remains constant, there is no real need to communicate. As a safety factor, it is good practice to do an        “ o.k. ” check periodically, even though the dive is running smoothly. It is also prudent to check more regularly when distances or depths beyond those dive team members have increased.

The best way to establish communications with a diver following you is to simply bend over and look backward between your legs. Stopping and turning around to ask a question is not the preferred method. If you are facing an oncoming current, it could push you into a reef, ceiling or wall and if the floor is covered with clay or fine sediment, stopping could increase the potential for silting. Communication signals can vary from one area to another and a review of communication is in order when diving with new team members or diving in new areas.

Slate

A slate can be used in case of total communication breakdown, however exiting the cave or wreck is preferred over a long discussion inside the overhead environment. During a discussion by slate the whole team has to stop with potential silting / zero visibility consequences, loss of line or navigation in regards on where the exit is and potential entanglement. The slate can be used for data logging such as turn pressure, time in or survey data. In emergencies such as a cut or broken line, or a lost team member a slate is very important in order to leave messages in the cave or wreck.

Light

Light signals are very effective and can be used in close quarters or large distances but a diver blinded by light is not able to communicate. It takes approximately 10 minutes for eyes to readjust to the low light environment. Depending where you are, shine your light onto floors or surfaces. When a lead diver asks a question relating to the entire dive team, do not respond until you have received the responses of the divers behind you. For example, if the lead diver wants to know if everyone is ok, pass the question back. Light position, distance and steadiness can be used to determine comfort and pace of divers in the team.

O.K. –  A light motion with a simple circular motion. The simplest question-response communication is, “Are you ok?” and “Yes, I’m ok.” The best way to communicate this to simply sweep your light in a circular motion on the floor or other surface of the cave or wreck. If your buddy is ok, he or she will then give the response with a circular sweep. Light OK signals are command signals as well and must be returned with an OK signal. Failure to do so needs to be investigated. Making a fast circular motion with your light could be misunderstood. It is often interpreted as a distress / problem related signal. If you are using the circular signal as “ok”, then sweep your light slowly.

Attention – A slow moving beam close or across a team members light beam indicates “I want your attention” usually followed by hand signal communication.

Emergency – An erratic or rapid light movements indicated that there is a problem and the team member using that light signal must be immediately investigated. Be prepared to hand over the long hose regulator and commence air sharing.

Touch Contact

Another area of communication occurs when following a guide line in very limited or zero visibility when hand or light signal become useless. The divers must maintain in touch contact with each other in order to communicate and the line in order to exit. The location of where the touch contact point on the body is depends on the cave or wreck passage size and configuration. In a large passage where divers can swim side by side the diver can grab the arm of the diver in front. In passages that are small or in restrictions the contact point is moving down to the leg to allow single file swimming. A firm hold to the buddy in front should be established and clear and concise signals should be used in order for our buddy in front to clearly understand the signals. The first diver out must protect the head to prevent head injury with possible unconsciousness or head injury, the second and third diver are protecting their heads behind the shoulder of the diver in front which helps as well in the streamlining of the whole team and a more efficient exit. Touch contact signals and communication can vary from one area to another.

Stop – One firm squeeze indicates the stop of forward movement. The diver giving the signal is usually the one who is giving the forward signal again to get the team into motion. Possible mask, ear clearing, gear adjustment or buoyancy adjustment could be a reason to use that signal.

Hold – A squeeze onto the hand that is holding the line indicates a hold in the exit process. Possible mask, ear clearing, gear adjustment or buoyancy adjustment could be a reason to use that signal.

Back Up – A pull backward on the arm indicates that the team must back up a little. Possible entanglement or verification of a intersection could be a reason to use that signal.

Forward – A clear push to the front indicates the team is ready to move.

Cross over Line – The diver in front is taking the free hand / arm contact hand and puts it onto the line pushing it back to indicate cross over and space needed, a small twist of the hand toward the direction of the cross over could help to understand which way the cross over is going to be.

Entangled – The line hand signal is pushed into the hand of the team member who is holding the line. If further help is needed the free / arm contact hand could be placed onto the entanglement to indicate where help is needed.

Emergency – A shaking motion onto the arm indicates an emergency. A possible out of air situation could develop and the long hose regulator could be needed to assist in an out of air emergency. One should be prepared that the out of air diver is pulling the regulator out of the mouth and proceeding to locating and securing the secondary regulator short hose.

Hand signals

While diving most communication will be done using hand signals. While giving hand signals and illuminating your hand with the light, never shine it in another diver’s face specially when communications occur in a low light or no light environment. Always point your light down or toward your lower body illuminating your hand full or partially.

Command Signals

OK – The OK signal is the same as used in open water but has more significance since it must be returned in the same way as given, unless there is a problem. If there is any doubt about the well being of all team members the OK must be given to verify that all members are indeed OK.

Hold – The hold signal is a closed fist shown to team members and signifies the hold or stop of the whole team. It is important that the hold signal is given back as a hold signal. The OK is not the correct response since it is not clear if the signal was understood.

Surface or Exit – When communicating that a dive is terminated this must be especially clear. The thumb up signal is used and all divers must return the signal with the same thumb up signal to acknowledge that the signal was understood, the team is to turn around and the cave or wreck is to be exited to the original entry point. The golden rule of diving is any diver can terminate the dive for any reasons, no questions asked, and no discussion. Reason may be cold, fatigue, and discomfort or as simple as thirst, hunger or enough time spend in the overhead environment and no time is wasted during exit.

Other Common Hand Signals

Turn around – The turn around signal is given when a team member wishes to turn the dive and exit but does not have the urgency as of the exit signal. The turn around signal is the index finger pointed up and moved in a circular motion.

Line – The line signal is used to initiate communication about line issues. The index finger is crossed over the middle finger and used in combination with the following four signals.

Entanglement – A figure eight motion with the line signal indicating an entanglement with the line that requires the help of another team member

Reel in – A circular motion with the line signal against an open palm of the other hand, indicating that the reel and line should be brought in.

Cut – A cutting motion with index and middle finger to indicate that the line has to be cut.

Tie Off – A circular motion with the line signal pointing down, a indication that this location can be used as a line tie off.

Silt – A rubbing motion of the thumb against the index and middle finger indicating that silt or sediments are close by or if agitated by a team member to make him or the whole team aware that a limited or zero visibility situation is imminent.

Bubbles – A tapping motion of the index finger to the thumb indicating that bubbles can be seen and depending on the size of the bubbles the diver or team decides to turn around and leave the cave.

Small / Big – A space between index finger and thumb indicating a lot with a large space between fingers and a little with a little space between finger. Usually this sign is used in combination with the silt or bubble signal to indicate the amount of silt or bubbles observed.

Question – A bend index finger resembling a question mark. This signal is given to ask questions and can be uses in combination with other signal such as bubbles, direction and team members.

Light On – The opening of the full hand with all fingers spreading indicated that the reserve light is on. When diving in caves we should look at our teammates periodically to see if the reserve lights are on and if so they should be deactivated until needed.

Out of Air – A cut throat motion with the hand indicating that the diver is out of air. This signal is used exactly the way as in open water diving and demands immediate action. Emergency light signal should be given at the same time to alert the other team members.

Decompression – The small finger (pinky) is extended while the rest of the hand is closed in a fist.

Direction – The thump is laying flat on top of the extended fingers pointing into the direction of travel while the hand is doing a waiving motion.

Numbers

One to Five – With the palm toward the partner extend one finger up for one, two for two up to five fingers to indicate five.

Six to Ten – With the back of the hand toward the partner and tilted by 90 degree extend one finger for six, two for seven, three for eight, four for nine and for ten give the signal for one and a zero a given an O.K. without extending the three fingers.

While reading this article please keep in mind that 99% of my diving takes place in the caves of the Yucatán Peninsula, Mexico. The opinions expressed in this article are based on my observations of the combined experience of Matt here at Protec, Hans Kaspersetz from Quiet Diver and myself.

Patrick decoing after deep dive in the Pit

I have found the X1 to be an extraordinary tool, considering the environment I dive in and the type of diving I pursue.  The X1’s design and features are both robust and easy to use and facilitate the type of diving I do on a daily basis.

I have used the X1 for: shallow cave diving, teaching and exploring; both in open and closed circuit modes; in environments from huge power passage to tight sidemount cave; for air, Nitrox, Trimix and Heliox; and for up to 7-hour long decompression dives with in water decompression as well as in a habitat.

There are certain aspects that make the X1 the perfect choice for me and here are some of them:

1. The computer is unbelievably small: I think this is a very important factor because of various reasons such as, less entanglement hazard while working with reels and lines, less crowded forearms especially while deep diving and the general minimalist approach of equipment in cave diving. The unit is nicely streamlined and can be carried on both arms with the option of flipping the screen. In cave diving, seize matters!!!
2. The solid body: Anyone that dives in caves will be able to tell you that it is extremely demanding on your equipment. Sharp edges and fine silt that enters even the tiniest orifice put your equipment to the test. The solid body, button less design and wrist mount from Deep Sea Supply combines to make a durable unit that securely attaches to your person.
3. The OLED display: Well, who ever has seen one under water or in pictures knows that the display is very powerful and also readable from almost every angle. A fantastic feature especially for exploring because you can still read the depth reading in extremely low visibility which facilitates the collection of data. In fact the display is so bright that I call it my 3rd back up light.
4. The compass: Honestly I would not use the compass for surveying BUT, you can use it to follow the general trend of the cave while laying line for example. It safes another spot on your arm, two birds one stone.
5. The integrated stopwatch: Very useful for timing decompression stops, low Po2 brakes in the water or habitat, slow final ascents, distances between way points in the cave, runtimes of DPV and many more.
6. The constant updates: Another awesome feature and they are FREE, when you use Ross Hemingway’s V-Planner Live. It is like getting a new computer every couple of months. The new software versions are announced by mail. To download and update your computer takes about 10min and it is easy even for somebody like me who is very inexperienced with computers.
7. The user elected menu list: The new software 4.25 gives you the option to choose the order of the menus. Meaning you can swap things around depending on their importance during the dive. Depending on the type of dive you maybe want to have the compass on first place followed by deco mixes and maybe then the lost gas option or maybe first stop tables then ceilings and display. Before every dive it’s your choice in which order they appear.


Hans preparing for a 325ft / 4.5hours cave dive

8. Plan your dive, dive your plan: I am a fan of Ross´ software since I first used the Z-Planner for deep diving projects in the Egyptian Red Sea. When I got my hands on the first multi-gas computers the calibration nightmare started. I don’t know how often I “bent the computer” because I followed the tables and my computer did not agree…what a nice back up?!? Anyway it always took some time to tweak the settings of the software with the ones of the computer to get them to more or less agree. Now having the same software in the laptop as in the dive computer makes really for nice straight forward dive planning.
9. The use: If this computer was any easier to use a monkey could do it, on a second thought maybe the ones at NASA can. But seriously the menu set up and programming is really great. You still should READ THE OWNERS MANUAL before you use it though. But after sitting and playing with the unit for like 20min you know it inside and out.
10. Customer Service: I have worked in the dive industry for about 8 years and purchased a lot of gear.  Unfortunately, my customer service experiences have been less then satisfying and I rarely have something positive to say about dive equipment manufacturers.   Most will invent the weirdest stories or blame you no matter how something brakes or doesn’t work as advertised. Sometimes it is even insulting.  However, I am happy to report that for the case of the X1 where you have to deal with two manufacturers: Liquivision and HHS Software, I received OUTSTANDING support from Margaret at Liquivision and Ross from HHS. They are incredibly fast when it comes to answering emails, are super professional and very helpful.  I had to deal with them for equipment failures and after a dive accident.

Patrick during Deco

Unfortunately, I cannot report only good things about the X1.  We suffered some hardware failures; however they were dealt with quickly and without cost to us.

1. Problem with depth sensor: There is a known problem, as stated by Liquivision, where the pressure senor port is filled with too much protective white goo.  When the computer is heated up by being in direct sunlight or in the sweltering jungle, the goo expands and the unit senses that it is under pressure and will not turn off.  There are fixes for the problem listed on the Liquivision web site.  If it occurs while on site, Hans discovered that he could just take the computer in the water and the goo shrinks and display the correct numbers.  Liquivision offered to replace the computer.
2. Missing pixels on the display: Matt and I both had some missing lines and missing pixels on the display after only a couple of dives. Liquivision replaced them at 0 cost and we kept the computers (since they were still absolutely usable) until the new units had arrived. The same day after sending a mail to Ross we had a new key to install V-Planner Live again at no cost.

All in all it is really a great tool with a wide range from exploring tiny caves in OC sidemount and getting good readings even in low viz which is crucial for collecting good survey data to several hour long deep cave dives utilizing CCRs with 20 different Bail Out mixes and habitats. The X1 with V-Planner Live is a great product that really jump started a new generation of dive computers. What a great time to be a diver ))

Photos by Matt and Hans

CCR (Closed Circuit Rebreather) cave cross over

I recently conducted a ccr cave cross over with Bill from Hawaii. The reason and purpose of the ccr cave cross over program is to combine ccr rebreather diving with cave diving. The term cross over is coming from the fact that a diver who had a cave diving education in open circuit as well as a ccr rebreather diving education who wishes to combine his cave diving experience with his rebreather experience.

The ccr cave cross over program to my knowledge (and I could be wrong) is only offered by two training agencies, IANTD and NSS-CDS. The prerequisites to participate in the ccr cave cross over is to be a trained cave diver with cave diving experience (75 cave dives with Bill) and to be a ccr rebreather diver with at least 20 dives and 35 hours on his unit (30 dives and 35 hours on his Classic Inspiration for Bill) to ensure that the skills of cave diving and rebreather diving a well rehearsed before bringing the two together.

The ccr cave cross over training program starts with a long discussion about bailout techniques and concepts as well as the advantages of diving a rebreather in water filled caves in terms of time we can spend and complex navigation we can do. Bailout is the alternative path to the surface in case your rebreather is non operational for whatever reason allowing us to return safely to the cave exit and surface. Bailout can be organized in three ways: open circuit (o/c), scr rebreather or ccr rebreather depending on a diver’s preference and recourses. Most divers opt for o/c as it is the easiest to obtain and simple. Team bailout concept versus individual bailout concept is a question about how much gas is carried by each individual, if the needed bailout volume to bring at least 1 ½ divers to the surface will be split in-between the divers or carried by each individual diver.

The complex and task loading training for the ccr cave cross over is coming from the fact that all cave diving related skills such as touch contact in zero viz, backup light exit, sharing gas in zero viz, lost line in zero viz plus the line protocol, team diving awareness and cave conservation have to be done using the rebreather doing them in the cave. The rebreather related skills such as partial and complete flood recovery, hypercapnia, hyperoxia, hypoxia, flying the unit manual as well as long horizontal o/c bailout swims have to be done in the cave.

All drills and skills are not new to the cross over student as he has done them many times before, only in separate environments and different breathing sources. The ccr cave cross over program is to bring the two together by first discussing the drills, then practice in openwater and then to practice them in the cave environment with safety and cave conservation in mind.

What will help the student is to have done as many cave dives as possible before the cross over as well as have done as many as possible rebreather dives on his unit. The basic operation of the rebreather should be second nature as we move from basic rebreather training and diving into a more advanced form of rebreather diving where we have two choices after an event on the rebreather which is either to stay o/c or go back onto the loop if we have figured out what is wrong with the unit, and go back onto the loop after a diluent flush to do a full or at least partial exit out of the cave using the rebreather.

Ccr rebreather cave diving is one of the most complex forms of diving due to the complex and task loading skills that need to be mastered by the ccr cave diver. To dive a rebreather in a water filled cave takes time to learn but can open new doors into the art of cave diving as we are not just going in and out of the cave anymore but are freed to stay much longer, as long as we stay within our bailout range and within save diving parameters including our consumables such as oxygen, diluent and Co2 absorbent duration and time limitations.

Save diving and greetings

Matt

Bailout is the alternate path to the surface if our rebreather does not work anymore for any given reason such as a full flood, not trusting the unit anymore, flooded handsets, malfunctioning mushroom vales or electronics failure. The CCR Cave Diver has a variety of options, scenarios and approaches that will get him back to the surface safely.

In an open circuit ( O/C ) bailout scenario the minimum breathing gas that is needed and to be carried by the team is the breathing gas volume needed to get 1 ½ divers back to the surface. In a rebreather bailout such as a SCR or CCR bailout rebreather a second rebreather can be used as bailout to bring us back to the surface in case of our primary unit malfunction. If we think in overhead environment terms gas planning , in particular the rule of 1/3’s a second rebreather might not be the end of the scenario but a third rebreather might be considered.

In the 1 1/2 diver to the surface scenario, diving in a team of 3 we calculate the gas volume needed for 1 1/2 diver and can separate the needed gas into 3 tanks, carried by three divers. The needed bailout volume is seen as a total carried by 3 divers. The team-bailout approach may work in most cases but it does not factor in a team separation, particular for the diver who is on its own who does not have sufficient bailout gas to come all the way back to the surface.

I believe that having and major rebreather problem that forces me to take drastic actions or even may force me off the loop, and due to that major problem in the cave environment we may create bad or zero visibility that could result in a team separation is not something I personally would like to leave out of the equation and my dive planning.

CCR cave diver with bailout tank

As the individual bailout approach is allowing to have for each CCR diver sufficient bailout gas to bring every diver separate to the surface, plus a margin of reserve the CCR cave diver has a larger bailout gas reserve. During later dives this can be practiced and then expanded upon to further penetration and team bailout approach as larger bailout gas volumes are needed if depth or penetration is expanded.

The whole bailout concept needs to be understood by the CCR cave diver in terms of not having all the time in the world anymore when on open circuit bailout as we are breathing our life support away, a breath at a time. Potentially we need to deal with some 25 – 30 % more decompression due to falling Po2´s on the way up and or poor bailout gas choices, depending on dive profile. Teaching a CCR cave course or diving with a rebreather in a cave without proper bailout planning capability to the student or diver is nothing else then giving the student or diver a loaded gun.

On open circuit bailout tanks a long 5 or 7 foot / 1.5 or 2 meter hose is a must and the deployment of the long hose from the always open and turned on bailout tank must be well practiced during predive safety drills. That will be a life saver and in some environments the only way to deal with a failed CCR while diving in a cave. Handing over the bailout tank in a fluid motion while sharing gas now on o/c and being under time and mental pressure will only lead to further problems, delays and stress. The hand over and sharing of the 7 foot hose, and not the handover of a stage tank will be the key to some real emergencies. However, the hand over and exchange of bailout tanks in-between divers must be well rehearsed to enable proper execution in case the skill is needed in earnest.

The choice between team or individual bailout, the balancing of bailout gas volume within the team, within all present bailout tanks must be discussed and rehearsed within the team prior diving and followed in either 1) team approach because the needed volume is split up in-between the team members and the out of CCR diver need their gas to make it back to the surface alternating between bailout tanks when the gas pressure reached 50 % of the initial starting pressure or 2) individual approach to have enough gas for oneself but not breathe the bailout tank totally empty and loose all redundancy when still with other team members, alternating here as well on the 50% rule. Larger bailout gas supplies are present with the individual approach, even when diving as a team allowing for delays exits such as restrictions, zero visibility, potential team separation and increased RMV due to stress.

When talking about the furthest point of penetration o/c bailout versus right before deco or close to exit bailout it is the furthest penetration that would be most problematic, as the divers still have to do the exit out of the overhead environment and then potentially have to deal with decompression. As we are talking about cave diving and not ocean drift diving we are able to stage the deco gas bailout if needed at the cave entrance. Having planned and carried sufficient bailout gas traveling horizontally through the cave will be the trick. Potential air hogs that go CCR to have more time in the cave still need to sling them large bailout tanks or they going to be running out of bailout gas fast. Taking a bailout tank without proper volume planning and reserves is like Russian roulette, and must not be done.

Besides opting for O/C bailout different options have been developed as Jochen Hasenmaier, Olivier Isler and the Wakulla II team went to SCR or CCR bailout for at least two reasons. First the bailout gas volume and the ability to carry it, drag and streamlining, second is time pressure of diminishing gas supplies and associated stress levels translating in potential errors and elevated RMV. If diving in deep caves the decompression obligation and related gas volume requirements are a factor too.

The bailout gas and volume planning will bring with it a change of breathing gas and Po2 at the bottom, changing decompression schedules and breathing gases needed to finish the warranted decompression. A dive computer capable of switching from O/C mode to CCR mode will help to control inert gas loading either wired into the loop with a separate sensor, or separate from the rebreather. Breathing gases as well as CCR and O/C operation of the rebreather can and must be changed when going from CCR to O/C in a bailout scenario in order for the dive computer to give us the correct inert gas load information. Diving with only one of such dive computers has no redundancy, that is where submersible tables or dive plans come in. Bailout gas volume calculations are a must and are done prior diving and separate to insure sufficient breathing gas bailout volumes.

In my opinion we need to take submersible bailout tables with us underwater in order to recalculate potential changes in dive plans as long we stay on our CCR. Submersible tables need to be designed for the breathing gases used during proper function of our CCR as well as the O/C bailout gases we may use. Planning dives with deco planning software including the calculation bailout scenarios with to deep and to long profiles as well as having them on a slate works well when diving known caves and profiles.