WWW.AQUALUNG.COM Dräger Ray semiclosed rebreather. Behind, an Rebreathers open Inspiration fully closed rebreather What is it like? WWW.AMBIENTPRESSUREDIVING.COM Text & photos by Peter Symes Diving Rebreathers Why bother? Rebreathers look cool, glitzy, tech- they provide for a much differ- nical and heralded as the future of ent and richer diving experience, which, in the first place, is why we go in diving, right? We read a lot about the water ourselves rather than watch- their impressive performances con- ing dive movies on Animal Planet from cerning duration of dives, gas econ- the comfort of our reclining chair at home. omy, extended no deco limits and However, as we all know, there is no such thing as a free lunch in diving either. There is what not. But isn’t it a bit like watch- a trade-off, and you will have to consider if it the underwater realm so you can have an ing Jeremy Clarkson from BBC’s car is still worth your while despite this. enriching experience by witnessing, first program, Top Gear, whiz around in It is not merely a matter of comparing hand, this magic realm. So, as far as I am fancy Ferraris and Aston Martins with technical matters, performance and param- concerned, if someone invented human eters when pitting rebreathers against the gills and a thin hide to cover and keep me a goofy, happy grin on his face and open circuits (regulators and tanks). It is warm, my twin-set would surely be left to rust reeling off a string of excited super- easy to be blinded by dazzling numbers and in the attic for good. latives? Yes, they look fabulous and facts on how much longer you can stay I just want to see fish and other underwa- under water with no deco-obligation and so ter life. I want to get as close as possible sound fabulous, but you’re still not on, but consideration should also be given without disturbing the sure what all the fuss is all about and to the sensation and experience of diving creatures, and for what’s in it for you... and whether you rebreathers. me, this is could actually afford one. I think these subjective matters have been exactly grossly overlooked in textbooks and articles. Rebreathers aren’t exactly an impulse buy, Yet, how can we put words to them? but they don’t quite require the same deep pockets as a super car. So, you could actu- Why? ally own one if you put your mind and piggy Wine connoisseurs have a whole weird bank pennies into it. vocabulary to describe all the flavours They do come with the same sort of built- of wines, but describing diving the in bragging rights and can still gather a rebreather experience to an open crowd on a beach. However, the glitz fac- circuit diver still feels somewhat tor shouldn’t be the only reason for getting like trying to describe a sunset one—there are easier routes to impressing to a blind person: “It’s... erh... members of the opposite sex. just really cool and... uhm...” Any piece of equipment is Diving experience just a means to an end and The reason to go with a rebreather should not the end itself. It is a means be their performance in the water, and that of transporting you down into Aaah! Silence at last—and the Unbearable Lightness of Being starts to sink in Black goby, Baltic sea 65 X-RAY MAG : 6 : 2005 EDITORIAL FEATURES TRAVEL NEWS EQUIPMENT BOOKS SCIENCE & ECOLOGY EDUCATION PROFILES PORTFOLIO CLASSIFIED Up close and personal. This squirrelfish Rebreathers tips almost sat on my mask what all the fuss and hype Comparison Rebreather-friendly is about with Let’s go on a dive and compare how dive centres & locations these gizmos. open and closed circuits perform. In Do check the list of so-called rebreath- I am a pho- the following, I will use a fully closed er-friendly dive centres before you go. tographer, so system for comparison rather than the It could save you quite some hassle aside from more widespread and more economi- and money. You can find these dive the better cally accessible semi-closed system centres on various lists, ie. online bulle- personal since the fully closed systems are the tin boards and web sites. For example, experience, I thoroughbred of rebreathers, and you could use this one at the Ambient can also get because I am better acquainted with Pressure web site: www.ambientpres- better pic- this type of system. surediving.com/ccrdbint.htm) tures when I Before we even get to the water, So far, it seems that open circuit sys- don’t blow or there is the matter of transportation. tems lead closed circuit systems 4-0 in scare all the If you are going to the beach in your the why-bother score due to the hassle and remains stretched like a drum-skin. critters away. own van, there is not much difference factor. If not, we have to go over all the seals For me, the in hassle when it comes to transporting and joints once more. longer no-deco a scuba set with tanks and regulators Before the dive The open system now leads the score times that these or a rebreather. OK, we are now at the waterfront with 5-0. units give me But if you have to travel by air, we all our gear spread out, rigging up. Mr. Next, comes the fire-up sequence are great but not are talking about a completely differ- Open Circuit mounts his BCD on a tank, where the rebreather diver stares very a prime concern. ent ball game. Going by plane, the regulator on top, opens the air and he intently upon the unit’s handsets (the Although, I have on open circuit diver can bring along his is ready to dive in a minute or so, save controllers). Do not distract her at this more than one occasion, or her regulator and BCD, or the diver the odd popping o-ring experience. No time! appreciated the fact that I can opt to hire everything at the desti- complications here. The electronics on the handset are could just stay down there at nation. The diver doesn’t have to worry Ms. Re Breather, on the other hand, taking the diver through a “pre-flight” depth to get my shot far long- about carrying tanks either, so there is has a lot more equipment assembly sequence of actions and tests, and she er than an open system would not too much excess baggage. to do, some testing on top of this, and must respond to these accurately and have permitted me. Rebreathers are different story. then some “pre-flight procedures” to observe closely that the rebreather Other CCR divers may have other undertake. responds correctly. By pre-breathing uses and other subjective reasons for The check-in challenge After assembling the unit, we first the unit, the diver makes sure that it liking their units. For instance, rebreath- It isn’t quite the same for the poor have to do a negative pressure test, operates properly before entering the ers have also become quite popular rebreather diver who might have to where we, under eye-popping strain, water. among some wreck enthusiasts, techni- schlep quite a bit more hardware onto suck all the air out of the unit, close During the start-up sequence, the cal divers and cave divers. the plane. It is not an issue to be taken the mouthpiece and watch it to breathing loop is filled lightly these days when airlines are less see whether the counter- with 100% oxygen Hearing and less tolerant of passengers who do lungs remain deflated and to calibrate Another major reason why I have not head weight limits and bring along squashed like vacuum- the sensors, a richer diving experience on my overweight bags. packed coffee. so we rebreather is that I can hear better—no The rebreather diver must rely on the After that, we then have to noisy breathing apparatus or bubbles— destination dive centre to fill his or her do a positive pres- and so, can more keenly sense what oxygen tank, and if the diver is lucky, sure test where is going on around me, even when I the dive centre can also supply CO2- we inflate the unit do see it directly. I have a much more scrubber and rental tanks. If not, well… fully and make it acute sense of the three dimensional let’s hope that overweight charges look like an over- space around me and what is in it. But aren’t an issue for you. blown tire to see let me get back to that later. if it holds pressure On a rebreather, I often get the sense that I can hear what is going on behind me 66 X-RAY MAG : 6 : 2005 EDITORIAL FEATURES TRAVEL NEWS EQUIPMENT BOOKS SCIENCE & ECOLOGY EDUCATION PROFILES PORTFOLIO CLASSIFIED A couple of worthwhile tips Rebreathers rebreather resources: www.therebreathersite.nl www.rebreatherworld.com Weight can As you descend, the increasing ambi- become a real issue ent water pressure also starts to squash Some manufacturers: when travelling with your counterlungs flat. They have about www.steammachines.com your rebreather. the same volume as a BCD, but need www.customrebreathers.com If possible, sort it a constant volume in order for you to M www.ambientpressurediving.com ot beforehand. have something to inhale. www.ccrb.co.uk Sometimes you can negociate a fair Unless you add some more air (or price on overweight diluent, which can also be some other (Above list is not exhaustive) before you go - or breathable gas) on your way down— buy some extra either by manual injection where you allowance.