Slow down and dive a little. A blog about cave diving in Mexico.

I posted a link to my article Last Dive at The Pit - Bailing Out at Depth over on Rebreatherworld.com.  One of the users, zzzzzzzz, commented on it and I thought his comment was worthwhile reposting here with my response.  The indented copy is zzzzzzzz's comment.

Good article.

WRT keeping on schedule, OC trimix should be running a set of schedules, allowing for aborted dive, short, long and maximum schedules. This provides all the needed flexibility in an emergency. Running a single schedule is not great.

Thank you! I write the articles for people to learn from and enjoy as entertainment.

The diver had the appropriate schedules. I am not sure where you read that we didn't have the schedules. Seems like you made a bit of an assumption to the negative. Our desire was to stay on the nominal schedule. As you might imagine, the switch to the next schedule at depth can add an unnecessary amount of decompression and gas usage. Every minute at that depth translates into about 5 minutes of deco. A switch to the next schedule brings a 30 minute penalty, something neither of us wanted to be obliged too. A close reading of the article reveals that my one minute to make the switch was built in to our nominal schedules. We left the switch on schedule.

This is to distinguish the need for time to solve problems versus making an expeditious exit. Since you experienced issues, it is astounding that the OC diver's schedules did not allow flexibility in running schedules. Certainly, a diver targets a nominal run time for a dive, however, not carrying contingency schedules is a fundamental training issue. Recommending that someone executes faster when encountering problems is not constructive since one cannot predict how long problem solving can take, especially in an emergency.

See above.

It is also quite okay to encourage better skills integration for enhanced performance, however, not because it is an inconvenience for the OC diver.

I see his recommendation in a different light. Optimally, I would like to be able to be swimming towards the exit while making the switch. That ability would cut at least 1 minute at depth and 5 minutes off of deco saving a little less then 18cuft of gas. Additionally, it would put me closer to the exit if there were another emergency, which out of respect to Murphy isn't completely unlikely. I can't remember a time when only one thing went wrong when things started to go really wrong. I think Santiago's critic is correct in that I need to work towards the ability to swim and make this switch at depth. I can do it in 100ft, why not in 280ft? That is a valid question and needs to be figured into bail out planning and needs to be trained further to develop better muscle memory. I don't think either of my CCR instructors would have let me walk without being able to do that skill while making an exit. I shouldn't accept it either.

On deploying and stowing regulators, especially on the fly, an added option is to set hose lengths such that the regs drape around the neck to staggered positions. This can allow maintaining several regulators in a deployed condition, allowing more time and options for stowage.

This is not a bad recommendation though going back onto the loop and doing 2.5 hours of deco this way wouldn't have been very comfortable. Again, this is a training and equipment issue and was only identified because I took the time to actually try it out.  I wrote that I have a similar problem when I dive OC with stages.  That should have been a warning to me that it would manifest itself when I dive CCR.  It is interesting that the problems we have in the shallows are magnified under the time pressure that comes with depth.

Thanks for taking the time to read my article and provide feedback! Your ideas help me to better flush out my ideas. Keep them coming

If you have been following Quiet Diver, you know that I left Mexico a couple of days ago.  And while I was in transit, I was torturing you with stories that were unrelated to diving.  Well, this story gets us back to writing about diving!

A month or so ago Santiago and I made a dive at The Pit down the Lins/Walten tunnel.  It was a nice dive to 238ft (73m).   Santiago was diving OC and I was on the Megalodon.   After the dive we had some helium left over and we enjoyed diving together so much we decided it would be cool to do a dive to the back of Wakulla Room as a team.  Additionally,  we needed to pick up some tanks that were staged from the last project and I still needed to do my at depth bailout.   So, we got another tank of helium and decided to do the dive in a couple of days.  Well, as the date approached I was too overwhelmed with work and had to call the dive.  These dives require a lot of preparation and mental focus and if my mind is on other issues, then I can’t do the dive.

Well, it took me more then a month to reschedule the dive between work and social engagements.  But once we got the dive scheduled everything fell into place.  All the gases were blended, regulators prepared and dive plans cut.

The plan was to stage gas at 20ft (6m) and 70ft (21m) on a down line.  Then set the primary reel and stage gas at 150ft.  For bottom gas Santiago took double 80’s and a deep stage.  I took two 80’s of deep bailout and the CCR.  Normally, I would carry one deep bailout for this dive, however since I was going to purposefully bail out, I thought it would be wise to carry extra gas.  As well, I was diving with an OC buddy and I wanted to be able to donate gas in the event of a lost gas situation.  After staging all the gas, we planned to swim to Paul’s Rock, which takes about 16 minutes.  Paul’s rock is about 800-900 (274 – 278) linear feet (meters) from the surface at a depth of 280ft (86m).  Upon reaching Paul’s Rock, I would signal Santiago that I was bailing out.  We would spend one minute sorting out the situation and then make for the exit with haste.  After exiting the Bypass, I planned to switch back onto the loop to conserve gas and do a normal CCR decompression schedule.

I had a several reasons for bailing out at depth:

1. Switch from a rich HE mix to a lighter mix and experience a change in END and confirm our choice of deep bailout.
2. Go through all the steps of bailing out under the effects of depth.
3. Confirm my SAC rate in that configuration and under the environment stresses.
4. Practice bailing out under the supervision of a trusted dive buddy at depth and get critical feedback.
5. Complete the drill because I made Patrick complete the drill and he was riding me about it.
6. Feel the tanks as they get really light with HE in them.
7. Breath open circuit gas at depth while hustling.  (I never dove Trimix OC.)
8. Practice, practice, practice!

The dive went nearly as planned.  We reached our way point at 150ft (46m) a little late, through a little effort we were able to make up the time and we reached Paul’s Rock on time.  I turned to Santiago and gave him an okay.  He replied.  I then gave him the bailout signal.  I reached up and turned the knob on my BOV.  I breathed out a little to clear the regulator of water and took a breath.  As I completed the breath I was immediately hit with a case of nerves.  I felt a shot of anxiety and adrenaline wash over me.  It was totally unexpected because I had mentally rehearsed the drill a pile of times and had executed it in shallower water many times.  My brain went a little mushy.  I reached around and opened the bailout tank valve.  For reference, I have my bailout tank and diluent tank plumbed into a manifold, so I now had access to both.  I had switched from an END of 67ft (20m) to an END of 92ft (29m).  Plus I went from an “unlimited” gas supply to a very limited gas supply.

After opening the bailout tank, I pulled my regulator out to replace my BOV.  As I pulled the regulator to my face, I reached up and pulled the BOV out of my mouth and thought to myself, "Don’t flood your unit - close the BOV."  I reached around and switched the knob, opening the loop!  Dur! I heard the bubbles and quickly stuck the loop in my mouth.  I switched the loop closed and cleared the regulator.  I thought to myself, "You idiot!  That is exactly what you needed to not do."  I took the BOV out of my mouth put the regulator in my mouth.  Confirmed I was breathing the right gas and looked at my set point controller.  I needed to set the set point down to manual.  It took my four tries to get it right.  I kept setting it to 1.4 instead of manual.   Finally, I got it set and then switched my X1 over to bailout, which I achieved on the first try.  I opened the OPV and started to swim.  The whole switch over took about 1 minute.  However, it really felt like a life time.  We swam for 5 minutes exiting the Bypass.  I switched back to CCR and made all the appropriate adjustments.

As we ascended, I picked up the staged tank at 220ft (68m).  The tank had been there for almost two months.  It was covered in billowing clouds of bacteria.  All the hoses were slimy and I was very glad I didn’t have to breathe from it.

The rest of deco went smoothly and was without incident.  Santiago and I had very similar schedules and exited the water pain-free.

As I hovered in deco, I had a lot of time to reflect about the dive.  The first thing that came to mind was how glad I was that I took the time to do the drill!  I wish I had done the drill last fall, when we first agreed that we would do it.  There is no harm in practicing this stuff, except to your wallet!  There is only benefit and experience.  Because my Meg is so reliable, I do not often get the opportunity to bail in a stressful situation.

Bailing out at depth in the back of a cave is different then bailing out in the first 1000ft (309m) of Ginnie, any shallow cave in Mexico or on the Jodrey.  I had bailed out repeatedly in those environments and never felt the anxiety or lack of coordination that doing it in The Pit caused.  I was definitely noticeably more impaired at that depth, even with a 96ft (29m) END.  I was glad to learn that my SAC rate held even at depth with a shot of adrenaline and a hasty exit.  I was also glad that I was able to get all the required tasks completed.  After the dive, I checked my loop for water and there was very little.  The towels in the bottom of the can were just a little wet.  So the open look fiasco wasn’t too detrimental.  I was glad that I identified that problem quickly and resolved it.

Santiago was concerned with how long it took me to bailout.  As he was on OC and run time tables the whole dive, he really needed to stay on schedule.  He suggested that I might have been better off starting to swim earlier.  I don’t know that I agree.  I think it is critical, even if I waste 1 minute, to get everything set and then start to swim.  I can only do one thing at a time in a situation like that, especially if my lizard brain starts to emerge.  In past situations, I really fumbled things by trying to do more then one thing at a time.  I have learned I need to complete one task then move on.

In response to his remarks and my performance, I would like to go through the drill again at depth a couple of times and maybe a couple more times in mid-range water.  I think when I get back to Q. Roo, I will schedule another bailout before I start deep diving activities at The Pit.  I may have the opportunity to give it a try this summer here in NJ.

Santiago said I looked somewhat impaired as I tried to set the handset.  I agree with his observation, I was.  Either it was anxiety or being narced.  I think it was an insidious mixture of both.  I know that when I get scared or nervous, even in shallow water, my cognitive abilities diminish.  Mix that with some depth and you have a nice cocktail.

Lastly, he was unhappy with how long it took me to get back on the loop and the distance I swam off the line when I switched back to the loop.  Both are valid concerns.  I swam off the line to avoid getting entangled.  As the line exits the By-pass it splits in two and ends up above you and below you in ugly spots.  So, I swam away from it.  As for taking too long, he was right.  I had a lot of trouble stuffing the hose back on the tank and as I was about to pick up another tank I needed to sort the bailout first. I think I need to get looser hose retainers and practice with them a bit.  I have a similar problem when I am dealing with my OC stages.

I am very happy with the dive.  It didn’t go perfectly, but I learned a lot and we had a ton of fun.  I am grateful to for my friend’s observations.  When you are in the moment, you miss things sometimes and a neutral observer can add a lot of depth to the discussion.  Santiago is an excellent diver and I look forward to my next opportunity to spend time with him.  I am sad because that was my last dive at The Pit for a while!  I really enjoyed diving at The Pit, especially the deep dives.  The Pit is a spiritual place for me.  I see it as a cathedral of diving.  The spaces are so big and beyond normal scale that it inspires me.  Until next time, I will dream of diving at The Pit.  To be honest, I am going to miss all my friends: Patrick, Solomon, Alain, Steve, Etienne, Ross, Katie and Santiago just to name a few.  The last year and a half of diving has been amazing and I have many fond memories.  Thanks to all of you, my life is forever enriched!

The last two days have involved a lot of driving.....  Made it too Austin last night, which was a monster drive.   We got to the border at 3:11PM and it took 1:42 to cross the border.  We got pulled for a secondary search which resulted in nothing but the bottom of the car getting tapped with a flash light.  It ends up that they checked and found we didn't have records, so they sent us on.  The weirdest part was that they didn't ask about the dog or want to see his papers.  So the effort to get new papers in Acayun was in vain, no one wanted to see them.

Today, I got started on the road around 11AM.  Driving was smooth and boring.  I decided to stop early here in Tennessee.  I am glad I don't have more to report.

Jesus Mary & Joseph! A guitar? Isn’t that where this story began? Is it your mission to subject people to cross country trips with guitars, that you don’t play? - Mom

Well..... As luck would have it the guitar played an instrumental role in our entertainment! We got pulled over for one military check point yesterday. It was after dark and I was a bit nervous because I wouldn't be able to watch them as closely in the dark.

The soldier was interviewing me trying to decide if he should search the car. He turned on his flash light and peered in. Then he started to asked about "cantar"... Jeff and I both looked at each other and tried to figure out what he was talking about. All that kept coming to mind was "enchante me". But I knew that was wrong. Jeff and I pulled out our dictionaries at the same time and looked up the word. We found it meant "sing". Now we were profoundly confused. Why was the soldier asking us to sing!!?? We just kept looking at each other and the soldier. I told the soldier that I didn't sing.  He looked at me suspect like it was almost time to search the car.

After another moment, I realized he was asking about the guitar which is on top of the pile. I explained it belongs to my wife.  I think we were both relieved.   I was very relieved to know I didn't need to sing to the soldier to continue on. I asked him, "Qiueres checkar?" He said, "No." and waved us on with a smile. I think it was the most stressful of the stops because of the confusion.

My poor black toe....

This morning started out like any other day that includes a global pandemic, a SUV loaded with all your stuff, and trying to sort out how to get new vet papers for your dog in a country that you only speak part of the language.

I got up walked down stairs to the truck, laptop in hand, and stepped off a curb and fell down really hard, slamming my laptop down on the ground and my body.  Damn did it hurt.  The end result is one very very black toe and a scraped up laptop.  Luckily, both my foot and my laptop still work.

Jeff and I ate some breakfast and then set out for the vet.  And believe it or not, we found not one but two.  Of course this was after asking 1 cop and 1 taxi driver.  Unfortunately, the first one had no doctor on site.  However, they directed us to another place.   The second vet was at a feed store.  After about 20 minutes of me trying to explain to him what I needed in Spanish, he finally started to understand.  An hour later, I had updated documents.  I will tell you tomorrow if they work.

Other then that, we tresspassed on some federal lands and drove all the way to Tampico.  Tomorrow, we make for the border and then a doctor to look at my black toe.

Yesterday, I promised you photos of the truck and all the stuff.  As you can imagine, every time we are stopped for a search, they really have to consider the amount of work they are getting into!

If you look closely, you can see a Apple Power Book, scuba tanks, a rebreather, guitar, camera back, and cans of tuna! No road trip is complete without cans of Tuna as emergency food. Especially, when you are at the epicenter of the pandemic!

Todays big news is that we made it to a cross roads town called Acayucan.  It is a sleepy town of 50,000.  Actually, there are people everywhere.  It is in Veracruz state.  The drive from Merida took all day.  We stoped in Campeche to take some pictures and in a beach town before Ciudade del Carmen.  We drove about 400 miles.  We were searched by the military 4 times and allowed to pass 3 times.  The searches went smoothly with lots of smiles and discussion about the dog and where we are going.  It ends up that I speak a lot more spanish then my driving mate, which is scary becuase I don't speak that much.  Luckily, we haven't encounted any impossible hurtles and things are progressing.  Tomorrow morning I am going to find a vet to renew my dog's papers.  They will expire and we are still two days from crossing the border

Charging headlong into the Pandemic of 2009, I am driving across Mexico heading for the United States of Disease and Debt!

On Monday, Allie and I decided to push our move up by about 1 month. In support of that decision, we flew her to North Carolina to spend some time with her family. That left me and Chico stranded in Mexico, a country that is spiraling into chaos and pandemonium. Actually, it isn’t! Most everyone is going about their business like they do everyday. The difference is there are less tourist around, which is nice.

Since, I didn’t want to drive across country alone, I invited my friend Jeff Knight down to witness the apocalypse first hand. With just a couple of hours notice, he boarded a plane against the recommendations of his trusted gubberment.

I picked him up. We packed all my crap into the 4 Runner and the three of us left Playa yesterday afternoon. You wouldn’t believe it, but all the crap fit, that is everything I wanted to take. However, the truck is riding on the stops. It isn’t the most comfortable ride, but it works.

Last night we spent a lovely evening in Merida at Luz en Yucatan, an AWESOME hotel.  We also ate dinner on the Plaza Mayor and saw some sites.  Today we are heading for Veracruz.  I need to make the border in less then 5 days because of Chico's papers.

I am sure you are wondering two things. What will happen to Quiet Diver?  Why are you moving?  Well, the blog will continue on!  Patrick will continue to write for it and I will be writing about my wreck diving exploits and learnings from NJ.  As well, we still have open projects in Mexico to write about.  When I left, I had just buttoned up about 5500ft of resurvey and exploration at my project site and I am starting the drawing process.  So, that will be fodder for the publishing beast.  Patrick is working on several cool projects.  And believe it or not, the Pit project continues.  Just a couple of days ago, I retrieved some of our deep bailout and bailed out at 300ft.  So there is plenty of material.

Now, you ask why are you moving!?  Well, Allie is pregnant with our first child, a boy.  We want to be near our family for the first year and milk them for all they are worth.  You know, baby sitting, money, and stuff!  The reality is that living in Mexico is really nice but we are isolated from our families.  So, we are heading home for now to work on our newest project, Project Mini-Me!

On a final note, if you have dug into this site you would know that Allie and I make our living by building web sites and web applications.  One of our most recent projects was a new blog for Protec Advanced Training facility.  Matt, Nando and Patrick are now publishing regular updates to thier blog.  So, if I am not keeping you filled up on news and factoids, head over to Protec's Blog and read up a little.  And if you need a blog or a web site for your business, email me at hans@quietdiver.com.  We are very competitive!

Keep reading!

Brian Kakuk has posted another entertaining entry in his exploration log.  The post details Brian's progress as he approaches the 1 mile mark in Dan's Cave.    The latest dive required 5 80 stages and two sidemount LP85s.  He is diving on Nitrox and reaching a depth in excess of 160ft.  I definitely enjoyed reading about it.   Make sure you scroll to the bottom of the page....

Right now I am in NJ paying my taxes and taking care of some other business.   I am really missing the caves and my friends in Playa!

On a seperate but related note, my web design company, Cyber X Designs, just launched Protec's blog site at http://www.protecblog.com.   If you want to follow the characters over at Protec as they guide, instruct, explore and fun dive head over to thier blog and leave a comment!

Patrick and I decided that we needed to go for a nice easy dive, one that wouldn’t include a huge pile of tanks or the mixing of exotic gases.  The answer seemed clear, go looking for Cenote Pabilany in Sistema Sac Actun (Grand Cenote).

The journey to this decision started last year or the year before. Patrick was diving his Megalodon in the western end of the Sistema Sac Actun.  He was near the Pabilany section but he was on the Paso de Los Pozos side.  He wanted to continue but found the restrictions a bit tight in the rebreather.  He finally retreated and decided to return in sidemount.  As time passed, the idea of diving this section of cave stayed with him, I moved into town and then we both got scooters.

With all the requisite gear and skills, we decided to scooter up there in sidemount with a single stage to check things out.  We sat down on Tuesday night and spent a couple of hours debating the best gas management rules for a scooter dive of this nature, finally settling on what we believe to be an innovative approach.  Secure in our planning we decided to dive on Thursday.

The dive plan was as follows: scooter up the main line jumping to the Paso de Lagarto. Continue scootering eventually jumping to the line to Lithium Sunset. When we reached our stage pressure or the T at Lithium Sunset we would stage the scooters and the tanks.  We would swim north on the Lithium Sunset line looking for the jump into Pabilany.  Once we found it, we would make the jump and a short foray into that section of cave.

The dive went almost according to plan.  The first obstacle was planning the dive.  Looking at the cave map and estimating the depths it looked like we might get into some deco with air.  Therefore, we decided to take O2, luckily the average depth was much shallower then we anticipated and the O2 was unneeded, which brings us to the irony of this dive.  Patrick and I wanted to make a simple relaxed dive.  Instead we ended up needing 4 tanks and a scooter each.  I guess when you compare that to needing 6 people and 35 tanks, this was a relatively simple and easy dive, but it was still not a no-brainer.

The second small obstacle was an exiting team.  When we got to the jump off the main line, there was a team of three exiting in backmount swimming with double stages.  We gave them the courtesy of waiting for them to completely exit the area before installing our jump.  This ended up taking 4-5 minutes as they lumbered through.  Not a huge deal, but hanging out and waiting, cuts into your stage and scooter time.

When Patrick and I scootered up to the T, our run time was about 23 minutes and we were both nearing our stage drop pressure.  It was serendipity.  We dropped our scooters and then our stage tanks.  In those 23 minutes, we coved about 2300ft, installed two jumps and a primary reel.  It was awesome.  The last time I swam to this spot it took us about 55-60 minutes to reach it.  I felt like we made pretty good time!

We started heading north looking for the jump.  We came to an arrow and decided to make the jump left.  We swam past a T, taking it to the left.  At this point the cave got tight with an aggressive saw tooth shape.  Then the line doubled back on itself and disappeared into a no-mount restriction.  Well, the truth is Patrick made it through with both tanks on and I had to remove one tank to pass.  The line through the restriction was on the ceiling in an awkward position.  Patrick squeezed through first with a lot of silting.  I followed him using the brail method.  The restriction required angling the body and ascending.  It was challenging and doing it in zero visibility made me nervous.

On the other side the cave opens up a bit and then pinches down.  I started to follow Patrick up, but the silting was just too much and my nerves were starting to fray.  Add to that the line was slack when we first entered the room and Patrick was actively fixing it as I followed.  Finally, I ran into his fins and decided I had enough.  I backed out and into the bigger room.  I decided to wait for him and meditate a bit.  When he returned a couple of minutes later I gave him the “Turn the Dive” sign.  By this time I had calmed down however he could tell I was a bit scared by the look on my face.  I hovered for a minute more and meditated.  I wanted to relax and prepare myself for passing the restriction a second time in zero visibility.

I descended back into the restriction and got a little stuck.  After a couple of seconds of fidgeting I popped out the other side and a wave of relief washed over me.

There is something exponentially more terrifying about following someone in extremely restricted silty cave then leading into that same environment.  All I could see was waves of silt coming down the slope, I had no idea where we were heading.  It ends up that Patrick surfaced just ahead of me in Cenote Azteca.  The last jump we made wasn’t to Pabilany at all.  We had missed the jump to Pabilany.

Once Patrick came through the restriction we gave each other the fist and started our return swim.  Our short stint up to Cenote Azteca didn’t use much gas, maybe a couple hundred PSI out of each tank.  So when we arrived at the T, we decided to check it out.  We swam north at a leisurely pass.  The cave was bigger and relaxing.  We passed over at least one jump and finally turned the dive at a single tank no-mount restriction.  We were nearing our turn pressures so we didn’t attempt the restriction.  When we reviewed the map we discovered we were in First Hope.

The trip home was flawless and we used less gas then on the trip in.  When we reached the O2 we had 90min of NDL, which was a comforting discovery.  Patrick and I both found the dive very satisfying.  It included sidemount cave, scootering, no-mount restrictions, and some very beautiful cave.  Our gas planning worked like a charm and gave us additional flexibility in the execution of the dive.  The only shortcoming was that we didn’t find Pabilany, though it did result in the happy accident of finding Azteca.

When should I get a rebreather?

Is it best to get some good caving experience before I go rebreather or is it preferred to get on RB as soon as you can? I know that I will definitely go RB one day, but I want to make sure I am not going too fast down that path.

I am Intro to Cave right now with 20 cave dives/ 250 total dives. — khacken, Cave Divers Forum

I saw this question on Cave Divers Forum today and started to write a short response that turned into a long response ad now it is a Blog post.

This is a pretty interesting question.  I learned to cave dive on OC back mount.  Then I learned how to dive CCR and did a bunch of CCR wreck dives.  Then I moved to Mexico and started CCR Cave diving.  Then I learned sidemount and found myself doing 80% of my dives, even in big cave in sidemount.  I have a couple of observations I would like to offer:

1. It is very easy to go beyond your limits with a CCR and not know it.  If you are only CCR diving, you have to calculate/guesstimate how long your bailout will last you in a very dynamic situation.  If you underestimate, you drown.  I think it is worth while to have dived many of those situations open circuit to see how the environment and situation will change your gas consumption.  This is in the same vein as swimming before scootering discussion.

2. Many many many situations in cave diving are not optimally handled on CCR.  Therefore, it is beneficial to have a broad set of options to solve your problem.  Is the cave small?  Go sidemount.  Is it unexplored?  Go with some 40's to check it out.  Are tanks and sorb available?  Use double 80's or go sidemount.  Is your CCR broken or too expensive for the dive?  Use OC.  Do you really want to spend your time setting up/breaking down your CCR for every dive?  NO!  Is the cave deep? Use CCR.There is one big caveat to this point, you need to analyze your diving and determine if you dive frequently enough to switch between OC and CCR and maintain two skill sets.  OC and CCR are different beasts and require different muscle memory.  If you dive sporadically, I suggest you dive only one system and you dive it in forgiving environments.  If you dive often, then you might be able to practice both often enough to be good at both, but this is very tough.  Sometimes when I am off the CCR for a month or more, I find it challenging for a dive or two.

3. Lets look at a side-by-side comparison of cost for diving.Typical shallow 3 hour cave dive cost the following for consumables.  The figures are USD.

Typical OC Cave Dive
Entrance: $10.00
Fuel: $10.00
Fills: $12.00 (3 Single 80's with Fill)
Total: $32.00

Typical CCR Cave Dive
Entrance: $10.00
Fuel: $10.00
B/O Fills: $8.00 (2 Single 80's with Fill)
O2: $12.00 (12cuft)
Dil: $3.00 (19cuft)
Sorb: $30.00
Total: $73.00

Add to the financial cost there is a time cost. First it takes me 30-40 minutes to setup the CCR and then it takes 20-40 minutes to break down the CCR. When I am on site, I need to check the unit and pre-breath it on top of my normal S drill. This doesn’t include the costs for O2 sensors or flying the CCR around or fixing it when you drop it. I also didn’t include the cost of servicing the regulators, because you need the same number or more with CCR. Remember with CCR, you need Dil, O2 and B/O regulators.

I am sure there are more reasons to choose one approach or another.  I can tell you that Patrick and I both own Megalodons and only dive them deep (>60ft).  Therefore, 80% of our diving is open circuit.

I think it is prudent to really consider where you are going to dive and the specific situations you will find yourself in.  If you cannot do that because of lack of experience, you need to seek the best possible training and gain the broadest experience possible.  Because you are already an Intro to Cave Diver, become a Cave Diver and make some dives.  Gain some experience.  Then start to layer on more technology, such as rebreather, scooter and stages.

So much of technical diving is about planning and choosing the right equipment and procedures.  Whether to dive OC or CCR, is one of those choices.

A great example is a dive I did with Santiago last week.  We dove the Lins/Walton line at The Pit.  I was diving CCR and Santi was diving OC.  We planned to make a 20 minute dive to 245ft.  When we got to 210ft at 6 minutes we found the end of the line.  I signaled to Santi asking him if I should tie in my reel?  He said yes and we went on.  We immediately found going cave and added 100+ft of line to the system and brought the end of the line to 238ft.  We tied off the newly laid line, installed our arrow and head up.  At 220ft, I found another lead with a nasty silty bottom pinching down.  After some inspection, I decided it was too nasty to attempt in CCR and I made the decision to return in sidemount to check out the lead.   I haven’t returned because I haven’t had the time.  However, because I know both systems, I have the option.

CCR was the perfect choice for the initial dive.  I used about $6 HE, $6 O2, $30 Sorb.  Santi used about $100 HE, $40 O2.  I did my initial exploration on the cheap.  Next time, I will go in sidemount and check out the lead.  It will cost more, but I will have a clear objective and the right tool for the job.  Fortunately, because I have a broad base of experience and more then just a hammer in my tool box, I don’t have to use a hammer on that screw.

I love my rebreather, I think it is an awesome tool that has enabled me to dive many places that few people will.  However, it is not always the right tool for the job and is not a panacea of safety.  Rebreathers fail and so you have to carry bailout.  If you bailout, you had better be sure of how much gas you need, because if you are not, fear will creep into your lizard brain and things will go to shit.  Therefore, if you are technical diving a rebreather and until we have truly fault-tolerate rebreathers or bailout rebreathers are standard issue, you need to have a foundation in open circuit.  The best way to develop that foundation is by diving open circuit.