Great discussions on this site!

STARDIVER

I am currently somewhere between a sport diver, and a wannabee tech diver. I am a rescue and recovery diver for my county, and get lots of exposure to austere conditions. I have done some deco, and have most recreational specialties under my belt, as well as several hundred dives, ranging from 30 foot warm water to 120 foot ice dives. I have decided to get trained on and purchase a CCR in order to access some of the great deep wrecks. I wish to understand the differences between the CCR units available, and choose the one best suited to my mission. If you have any comparative remarks on the units available, specifically the models best suited for long deep dives, I am VERY interested. Thanks!

EBT

Hi,

it might help if you could give some guidance on what you class as "deep" or "long".....

/Zak

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STARDIVER

Zak,

I guess deep would mean 250-350. Long would mean great enough duration to descend, visit, and ascend, allowing for necessary deco. I understand the need for mixes at these depths, and another requirement for the unit I purchase, would be that it is easily fitted with mixes. Perhaps you could also explain to me the preference for Manual inhection CCRs. I do not understand why one would not choose a computer controlled unit that could handle mixing. I understand the principles of CCR's, but not the details necessary to operate one. Thank You. SR

EBT

Fair enough, I ask because everyones definition seems to vary. You still dont mention duration though?

Essentially, my criteria for unit selection are driven by;

1. Effectiveness/size of scrubber, the whole unit really exists to support the scrubber.
2. Reliability of unit (Im a great beleiver in things that just work)
3. Ruggedness of unit.

Reasons I went for manual addition. Its reliable, Im in control, theres less to go wrong and it lets me wobble around the PO2 to suit different deco strategies. So far its worked a treat (touch wood), although obviously you dont have the benefits of blind operation like you can have with eCCR.

I dont really have aspirations to go much over 110m, so the KISS is fine.

In your case, you want to do some reading around the things that impact scrubber duration and get an understanding of that.
Then consider how the unit helps you in shit/fan interface moments and how else you can mitigate those.

Units you'll probably get pointed to are ; Boris, inspo, meg. Its also worth considering KISS and taking a look at the bigger PASCR units. Anything with a small scrubber should be considered critically.

/Z

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STARDIVER

Zak,

Your advice is well heeded, and I must agree with the theory, at least concerning your selection criteria. I certainly cannot speak with the voice of CCr experience, but my trials with OC gear certainly lend credibility to your criteria. Would the RB80 qualify as a PASCR unit? I read that duration on that machine was in excess of 10 hours in some trials. I was quite interested in the RB80 until I learned that it required 3 DIR Halcyon courses prior to being allowed to train on the unit. These courses pushed its price point well past the desireable. The Meg seems to be a very popular unit, but I am equally enamored with the KISS, despite the potential depth limitations. Thank You very much for your input and suggestions.

EBT

Yeah the RB80 and clones are PASCR. Its got some validity when operated within the bounds of their "system". As for the 10 hour scrubber, I honestly have my doubts it'd be anywhere near that within a CE test regime.

My best advise to you is read lots... question a lot.... and make your own informed decision.

If you want to see units in the flesh, try taking a look at Curts days (advanced diver magazine), he tends to get KISS/Meg etc together in one hit.


/Zak

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Dutchy

Forget the RB80 if you're after some sort of CCR. Although the RB80 has a great reputation in exploration diving it's basically an SCR and you'll consequently have bubbles. From "long and deep" if deduct that you might not mind that because you're after wrecks not marine life...but hey if you were prepared to couch up the dough for a RB80 then know there are similarly priced Rebreather's around (both mCCR and eCCR) that you might want to consider.
Some things to thinks of:
Price - Think of both the Rebreather and the Training and the travel costs to obtain such training.
Spares/Repair - Would you like to ship your Rebreather in case of troubles?
Limits - Both time-wise and dept wise there are some limits associated with Rebreather's. Make sure you compare the same things. A machine might be CE rated with sofnolime for 4 hours whereas another user will claim he did 7 hour dives without probs.
Features - Would you like to have an integrated computer or would you prefer a separate one (with the model of your choice) Is there a need to plug in additional gas? Some features may be added later but would you rather have it integrated?

If you are looking into CCR you'll find that they all do Tx. Differences will be in the area of confort level for a particular type of dive. E.g. mine is great for travel. (But only has a 2.5 hou scrubber)

Jeffrey Bozanic wrote a nice book. Although it doesn't cover the latest generation of rebreathers it's a great starting point as you'll find many biased ppl here that love their own Rebreather best....

Search for that name and you'll find a link I posted it before....

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STARDIVER

Thanks for your suggestions and input, everyone. I have dropped the RB80 from my list due to the functional and fascist limitations of it. This is a wonderful site; where else could I have learned this much so quickly?

UKSteve

decoweenie

If you decide that quickly, you will be buying a Meg pretty soon with this crowd...

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