Rebreathers, Partially closed or fully closed?

[ScubaJewel]

I would like to hear everyones opinon on diving with a partially closed circuit or a fully closed circuit unit?

Thanks

Julie

 

[BigJetDriver]

Julie,

The CCR is the best machine, bar none, for giving you the "best mix" no matter what your position in the water column because of its ability to constantly change the fractions of the gas that you are breathing. The CCR is also best when it comes to duration at depth. The new ones, such as the Inspiration are quite reliable, and relatively easy to use.

The down side of the equation is that they are more expensive than SCR's. Both the SCR and the CCR require type-specific training, and a different "mind-set" than OC diving.

Hope that helps. =-)

BJD

P.S.---I would suggest Jeff Bozanic's book on rebreathers from Best Publishing.

 

[madmole]

A lot also depends on the type of diving you do or may do in the future

Semi Closed units (SCR) are ideally suited to recreational depths and give extended dive times and a little advantag in decompression. They become limited as you go deeper and although many people do take then deeper than 40m they are getting out of their element

Closed Circuit units (CCR) can be used at virtually any depth most of us mortals would consider sane. They give an ideal gas mix at all depth and really do extend your duration at any depth and minimise decompression. They also considerably reduce you gas bill if you are using helium mixes

Down side to both are cost (CCR cost more than SCR, both cost more than Open Circuit (OC)). EXtra training is required, more preparation and predive care is required, and you are introducing more ways to kill yourself on a dive

Up sides are warm, moist gas (no more dry throat), a more natural breathing pattern, no more worries about gas duration and more options if things do fail

You still need to carry enough OC gas to bail if the unit fails, so dont expect an RB to reduce the load you carry (unless you are diving above 30m when the unit has enough gas on board to bail, unless you have a large deco overhead)

There are 2 really good books on rebreathers in general and most of the manufacturers publish their user manulas on line

I know I biased but take a look at my website. I have a library section that has reviews of the books and you can download all the Inspiration stuff from my site

Your choice of breather may be limited by your location, so tell us where you are and what sort of diving you currently do and plan to do and we can make a suggestion of which units you should be looking at

Be aware that there are no perfect rebreathers and many folks get very protective about their particular model. Make your own decisions and get as many try dives in as you can

 

[db8us]

Hi Julie,

i have to step up to the soap-box for the SCR-machines.
At least passive SCR like the RB80 are used for deeper and longer dives, like the can be found on www.wkpp.org or www.ekpp.org
But then you are also in the same price-class as you are with an CCR.

For me the primary question is: Do i need a rebreather ?

Michael

 

[BigJetDriver]

db8us once bubbled...
For me the primary question is: Do i need a rebreather ?

Michael

...And here we all thought you had made that decision already!

P.S.---The deepest RB dives have been done on CCR's.=-)

BJD

 

[db8us]

BigJetDriver69 once bubbled...


P.S.---The deepest RB dives have been done on CCR's.=-)

BJD

Does this say somehting about the Intelligence of the CCR-users ?


I do not get the point

Michael

 

[madmole]

I thought the deepest and longest dives where done on OC, Many of them are still down there!!!;-0

Depends on if coming back up after the dive is a critical criteria of success or not

Deepest depth, longest dive, furthest penetration etc say more about the mentality of the diver than the kit they use. There is always more than one way to skin a cat!!! (Unless your DIR , in which case you HAVE to use the Halcyon Cat Skinning Kit, worn on the left side)

Personally My shortlist would be Insp, MEG, Prism, RB80, Ourobouros, KISS. These units can all do the sorts of dives I want to do, all work, all are well made and despite the protests this will cause, are all capable, safe, functional units if you are trained properly in their use

Factors such as location (most of these units are technically illegal for us to buy in Europe), Support, can you get spares at home and when travelling, delivery time (couple of weeks to nearly 2 years) and petty politics (will inspiration owners be allowed to buy an RB80?) will also dictate your choice.

Find someone near you that has a unit and talk to them, Many instructors will run a try dive for you and spend some time showing you the units and the pro's and con's

Swapping to an RB is not an easy (or cheap) descision, knowledge is definately power here so read all you can and ask as many questions as you want

Its just like buying a car, you want a new one, but which, there are so many and they are all different, all have good and bad points and all makes have their followers who wouldn't touch another make. I reckon (sorry, but I'm English) and dont take this too seriously

Inspiration = Ford, lots of em, cheap and functional
MEG = TVR, Swish, Flash, Pretentious
Prism = Porshe, Owners look down at others (Joking guys!!)
Ouroborous = Daimler. Looks good but based on old designs
KISS = Land Rover, basic, tough no thrills
Mk16/15.5/16 = Rolls Royce. Expensive and getting on a bit
RB80 = Audi, dependable and reliable
Dolphin = Skoda, Basic, functional, keeps on going
Azimuth = Fiat. looks nice, but not so good to drive and falls to bits

Right, now I've offended everyone I'd better do some more work

 

[pipedope]

Is the first question.

Besides all of the mainstream rigs previously listed there are the build your own types. Some people say, "If you can't build your own rebreather you shouldn't dive a rebreather." I don't go that far, but there is *some* basis to it.
For some interesting reading;
http://home1.gte.net/doctrbob/CCO2.htm
http://www.atlimp.com/dive.htm
http://www.nobubblediving.com/

Training is a whole additional thing.

 

[jptrealty]

The PRISM in no way should be considered the PORSHE, it is likely the worst unit of the list you mentioned. If you would compare it to cars, I would say it is the equivelant to the LOTUS ELAN the one made in the US that was garbage..


Thanks

I thought the deepest and longest dives where done on OC, Many of them are still down there!!!;-0

Depends on if coming back up after the dive is a critical criteria of success or not

Deepest depth, longest dive, furthest penetration etc say more about the mentality of the diver than the kit they use. There is always more than one way to skin a cat!!! (Unless your DIR , in which case you HAVE to use the Halcyon Cat Skinning Kit, worn on the left side)

Personally My shortlist would be Insp, MEG, Prism, RB80, Ourobouros, KISS. These units can all do the sorts of dives I want to do, all work, all are well made and despite the protests this will cause, are all capable, safe, functional units if you are trained properly in their use

Factors such as location (most of these units are technically illegal for us to buy in Europe), Support, can you get spares at home and when travelling, delivery time (couple of weeks to nearly 2 years) and petty politics (will inspiration owners be allowed to buy an RB80?) will also dictate your choice.

Find someone near you that has a unit and talk to them, Many instructors will run a try dive for you and spend some time showing you the units and the pro's and con's

Swapping to an RB is not an easy (or cheap) descision, knowledge is definately power here so read all you can and ask as many questions as you want

Its just like buying a car, you want a new one, but which, there are so many and they are all different, all have good and bad points and all makes have their followers who wouldn't touch another make. I reckon (sorry, but I'm English) and dont take this too seriously

Inspiration = Ford, lots of em, cheap and functional
MEG = TVR, Swish, Flash, Pretentious
Prism = Porshe, Owners look down at others (Joking guys!!)
Ouroborous = Daimler. Looks good but based on old designs
KISS = Land Rover, basic, tough no thrills
Mk16/15.5/16 = Rolls Royce. Expensive and getting on a bit
RB80 = Audi, dependable and reliable
Dolphin = Skoda, Basic, functional, keeps on going
Azimuth = Fiat. looks nice, but not so good to drive and falls to bits

Right, now I've offended everyone I'd better do some more work

 

[caveseeker7]

The PRISM in no way should be considered the PORSHE, it is likely the worst unit of the list you mentioned. If you would compare it to cars, I would say it is the equivelant to the LOTUS ELAN the one made in the US that was garbage..


Thanks

If you want to compare the Prism to a Lotus, it would be the Elise.
Well engineered, light weight, high performance.

At least you can spell Lotus. Porsche does have so many letters ...