Tech Diving: Rebreathers …

By Steve Lewis

Steve Lewis and one of the twelve rebreathers heas owned; simply make sure you invest in the right tool
for the job. Photo: Jill Heinerth.

So, youare looking at taking the big step into rebreathers, are you? Letas chat.

Itas okay, your secrets are safe with me. Iall admit it, I have owned a few rebreathers myself. At last counting, there have been twelve. But no worries, I am getting better, the psychotherapy is working, and there are only two sitting in my scuba shed right now.A

Whatever the word is a you know, the one putting aside for legislators, telemarketers, and for those who knock on the front doorway just as youare jumping into the shower a well thatas the word that best describes how I feel about rebreathersa | most of the time.

However, please donat get me wrong. There are times when I will not dive anything BUT a rebreather, because it is simply the very best alternative for the job in hand.

So perhaps I should start by trying to explain the dichotomy.

When they are set-up correctly; when all the assembly and pre-dive checklists have been fulfilled and run smoothly, when every aspect of the rebreather unit is working as it should, they are great. When all those necessary details are squared away, there is nothing more relaxing , nothing more comforting and peaceful, and nothing more fun to dive than a rebreather.

The benefits of abundant warm, moist gas being delivered with precisely the arighta balance of oxygen to diluent are hard to beat. Rebreathers often have the added and related benefit of delivering their owner back on the surface in better shape physically and mentally than when they started their dive.A

Decompression stress is mitigated compared to someone doing a similar diving on traditional open-circuit gear. Also, a rebreather diver has not had to hydrate and warm-up every lungful of gas, and because of that, his or her fatigue level is likely less. And on a long-deep dive necessitating helium to cut both the effects of nitrogen narcosis, and to help manage loading of central nervous system oxygen toxicity, the rebreather diver has more money left in his or her pocket at the end of the working day to buy a post-dive celebratory round of cappuccino, ripasso, or whiskey sours for their dive buddies.

And, perhaps the least talked about benefit of all for the tire-kicking public considering a rebreather buy, if something does attain the fan at depth, the well-trained, well-practiced, properly kitted out and aware rebreather diver has many more options to get safely back to the surface than squad members breathing open-circuit gear; many, many more options.

All told then, when everything has been done correctly, according to Hoyle, the useras manual, training courses and experience, well then, rebreathers is not the most comfortable and easiest thing to dive, but they are also the safest option.

All in all , not a bad equation.

But being a realist get in the way of me lies in the facts of the case that cheerleader of CCR diving you assure prancing around at your local dive site telling all and sundry that, aOnce “youre starting” diving a rebreather, youall never go back to open-circuit! a Frankly and candidly set, rebreathers are exactly the right tool for only a very select and very small niche in the scuba diving community. At least, in my opinion.A

Without argument, for that select and niche marketplace a rebreather of one flavor or another is the perfect answer for most dives, but that doesnat change the fact that itas a small and select grouping. And that reality influences my exuberance solely, to the point where Iave perhaps talked more punters out of to buy a rebreather than Iave talked into it. And that is not best available career move for someone whoas served as a product consultant and factory-sanctioned instructor-trainer for a couple of rebreather producers!

So, letas get back to some of hard facts.

First off, if your notion of putting your dive gear away at the end of a trip-up is to reserve a corner of your garage or tool shed because, aIt doesnat matter if the floor get wet, and piled up like that in the corner my dive gear is out-of-sight and out-of-mind until I next need it, a please turn away now and donat look back. Opportunities are better than a guess that youall be wasting your time and fund. After a few weeks of being ridden hard and put away wet, youall be sending your division back to the manufacturer for a major overhaul and rebuild. And thatas the best-case scenario.

If your notion of putting your dive gear away is piled up in the corner, please turn away now and donat look back

However, if you are reasonably meticulous, enjoy maintaining your stuff looking good, and as a personal rule love to set things away in their designated place a are ALL the bits and pieces of your socket defined present and put away in the right place a you have passed the first barrier.

At their very basic, rebreathers are actually as simple to maintain as rinsing with fresh water, sterilizing the breathing loop-the-loop and counter-lungs, drying them, and then putting them where spiders, chipmunks, and glitches canat put up home. The other basic chores include emptying the scrubber material, and stimulating sure the head, controllers, and oxygen sensors are stored someplace warm and computer-friendly. But if you have doubts, redirect your rebreather money toward that journey of a lifetime youave been thinking about.

Okay, second barrier. How many times a month do you dive? Perhaps that should read, how many times a week do you dive? You may, like me, live in Canada and weekly dips are a challenge for part of the year at the best of times.

Regular use and a deep familiarization is a prerequisite to remaining safe. Rebreather diving goes a whole lot better when you recollect precisely where the breathing thingy plugs into without consulting a division schematic.A

Following the manufactureras checklist helps a and is a involved safe-practice a but a checklist is not infallible and isnat going to help if it lacks precise detail and you canat remember, for example, which side of flange C is the one that phases in the direction of gas flow.A

Also, the skillset needed to run a rebreather in the water is a mite more complicated than abreath-in, breath-out, recur as necessary.a All skills are perishable, and if itas been a few since you last practised a diluent flush or operate your division semi-closed, or if for instance you arenat sure what the appropriate sequence of actions is to manage and deal with a stuck solenoid safely at depth, this is necessary business practices diving or even a full refresher before venturing anywhere interesting.A

A good buddy recently sold one of his CCR divisions because even though he was an active instructor on it, head been unable to put in any time on that particular division for several months. aI love the human rights unit, a he said a little sheepishly. aBut Iave forgotten how to run it safely.a

So, if you are an avid diver who is able to invest the time, attempt and fund if maintaining abilities sharp and experience current, welcome. You have attained it passed barrier number two.

Next: what type of diving do you do? Are you a photographer; do you shoot video? Answer yes to either of those and youare definitely a candidate for a rebreather. Your interactions with marine life are expected to take on a new level of intimacy when you are not spewing out a creek of noisy bubbles several times a minute.

Okay, another question in the vetting process! Do you currently spend the equivalent of a semester or two of college tuition on helium? A

The gas efficiency inherent with a closed-circuit rebreather genuinely is remarkable, and it can show itself in bold black( or red) figures when it comes time to balance the books. On a recent live-aboard the average cost of helium for the CCR team was around one-fifth of the cheapest bill for one of the folks diving open-circuit!

Final question: do you have concerns about being able to afford a CCR? A

This is a lot like the tale about the luxury-car salesperson who tells a friend that if a customer asks the cost, nine-times out of ten, they canat actually afford the car.

Now donat misunderstand, everyone has to be price-conscious, but the initial be invested in a CCR and training, and keeping up acquaintance by diving it regularly is expensive. If youare on a tight budget, be realistic about the required expend to get into CCR technology.

SomeA numbers

Now, a wholly manual bare-bones sidemount division from Kiss is going to cost a third to half the price of a state-of-the-art, expedition-grade Red Bare unit with the appropriate bells and whistles, but neither is precisely chump change .( And of course, both are primarily designed for most varied applications. What that means in practice, is you may want to buy more than one type of division. Did you just holler ?)

Training is going to cost around $1500 and will take seven days a so taken into account in traveling and living expenses for you and perhaps your teacher during your training.

If all that voices feasible and you think youare a good nominee for CCR, thereas one more question. I know I wrote final question one step back, but I lied.

Are you in decent shapea | as fit as a butcheras dog? An alarming number of aaccidentsa on rebreathers have had diver fitness as such factors. This is a dodgy topic and one that some educators/ marketings people dismiss, and one that one has to be careful about; however, age/ weight/ fitness related issues have been were mentioned in a number of fatalities and near-misses. I have heard about a growing number of teachers who are very particular about taking on students who may be at risk because of these factors. They are asking for a very thorough medical sign-off. Again, if you have doubts, please suppose long and hard about your suitability for the added stres of carrying a CCR, bailout bottle( s) and abruptly having its full potential to dive deeper, longer and harder than you are used to.

The message here is that a CCR might be the best thing to happen to you and your diving; merely be realistic about the connection and appropriateness of it for you.

Okay, time to afess up. I have to go now and pack one of my CCRs for a cold water wreck diving trip-up. In this particular case, my rebreather( a Hollis P2 in case youare interested) is genuinely the only thing I can trust thatall do the job I want it to do.A

Steve Lewis is an writer, adventure traveling consultant, and a technological diving instructor-trainer/ evaluator. He lives in a small converted 19 th-century schoolhouse in the wilds of Muskoka and has what he terms athe good fortunea to travel around the world to lecture and teach .

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