What's a rebreather?

[Life-Is-Good-Diver]

Thanks Dave for answering that, i was right behind ya there.
Sorry guys for making this seem like us vs them, I get a little perturbed when folks start stating things like they are facts when they dont know the correct answers. I dont spend much time on the regular scuba forums for this reason. I was alerted to this post by a buddy who said I really should jump in and rebutt the crap with facts.

Everyone is certainly entitled to an opinion, however you should state opinions as such. As in "in my opinion, playing tennis is a very dangerous sport, and those participating in it are in great danger of losing their limbs from the stress on the joints"

what you have stated is put out as fact, with no backing information, this is what gets my dander up. The information I have posted is much more fact than opinion, with the articles and experience to back it up. I have written articles on rebreathers that are available on my website as well as RBW and soon to be in Advanced Diver Magazine. If you would like more info on RB's, that is a great place to start, as rewriting all that info here would be rather redundant.

In my opinion (see how this works) Rebreathers are as safe as the diver, and the instructor who taught them, if you dont have a safe mentality, do proper pre dive checks, follow checklists etc, then you have no business diving a RB. We dont need more bad press.
I would love to have a reasonable discussion with anyone on the subject of RB's, but please dont come across like you know everything when you dont. Please allow someone who actually knows the answers to respond. I am not saying that I know everything (or everyone either : ) but I have been been doing it for a while, and I will be diving this afternoon, with 4 other RB divers and 2 OC divers too. As long as you are diving, having a good time, then go for it.

It does make for a lively discussion doesnt it? dont get me started on DIR...

Well said, I been watching your post with and didn't know David Shaw was a friend of your's as well, sorry to hear about what had happend to him, I must have read that artical over and over a dozen time's.

 

[JonnyB]

Hi Alix, i wanted to add something to this thread as well.
I have great respect for Stefan and Ron for what they write,
i do recommend you to look around at www.rebreatherworld.com
I myself dive a few units, I just sold my classic KISS to get a Megalodon
and i have been trained on inspiration.
My personal opinion is that you can actually teach someone from the very begining to become a CCR diver, and if i am not mistaken i belive that IANTD actually aproves this. I might be wrong but i remeber correctly, IANTD allows you to do NITROX and ADV NITROX together with your CCR training and you can do that apart of your Open water training, just after your first OC dive. This is not bad as many people experience the crossover to RB to be like forgetting everything you already know about diving and start over again. And also many people who are diving ccr find it very difficult to do a oc dive when they've been on ccr for some time...
I believe that for the skilled diver ccr is far more secure than any other system, but in the hands of a person that does not show it the respect it demands it will turn around at some point and bit you in the *****.
Remeber folks Murpy is allways lurking around the corner, no matter what you are doing, but inviting him in when you are doing something demanding, that is just plain stupid. When it comes to me and my rb diving, i am 100% rigind, i do all my predive, on dive and post dive. And i will rather call the dive than to be strassed into it. And so i have done many times. I am ready to dive when i am ready to dive, most of the time i am ready long before any other oc diver, mainly beacuse i do all my setting up the night before...

Hope this helps, and dive safe!

/Jonny

 

[CaptainNemo]

This is the same guy who said you can get bent from a 40cm error in deco stop and now you're saying how dangerous rebreathers are. Listen man why don't you take up golf, you'll be much safer!

FOUR!

 

[CaptainNemo]

Yes. Particularly divers who set off to do dives which are beyond their capability - be it on rebreathers or any other piece of life support system.

Mr Espenskogen,
I was thinking about going to the moon and I was wondering if you could tell me how to build a spaceship? My point is, I come here to learn from others experience and not their opinions or rehashing of other peoples knowledge. That said, it appears you have an itching to don a rebreather so why not sign up for a course. Good luck and great diving.

 

[DiverBuoy]

What is a rebreather?
... In my opinion, a superior diving system

Jeffrey E. Bozanic, whos book Mastering Rebreathers, I consider the rebreather bible, says: A rebreather in its simplest form, is a machine that cleanses and conditions the gas a diver exhales so that it may be breathed again ...

There are two types semi-closed-circuit rebreathers, SCRs, and closed-circuit rebreathers, CCRs, the fundamental difference is how they function. SCRs: vent some gas, make bubbles, during use and CCRs retain exhaled gas, no bubbles.

Benefits include

• Gas efficiency, less loss
• Less noise (huge bonus for uw photo/videographers, without scaring aquatic life)
• Reduction of equipment
• Reduction of weight, easier to manage
• Breath warm moist gas
• Dive much longer on the same tank fill
• With appropriate mixes, prep and training dive deeper
• Users claim to be less tired after repeated dives (though scientifically unsubstantiated)

SCRs are "inexpensive" as low as 1200 bucks retail. They do require additional levels of training and certification. Training is more expensive and complex, but don't let that scare you, it's not overwhelming and the trade off is worth it. Slight additional cost in consumable materials, specialized gas fills, and to an extent maintenance costs.

 

[TSandM]

And also many people who are diving ccr find it very difficult to do a oc dive when they've been on ccr for some time..

The only person I've ever talked to who has actually got a lot of experience diving a rebreather told me that his bailout is OC . . . and therefore he had to stay current on all his OC skills. Is that not true? (Asking as somebody who has no clue, but has been reading this thread out of curiosity.)

 

[DiverBuoy]

The only person I've ever talked to who has actually got a lot of experience diving a rebreather told me that his bailout is OC . . . and therefore he had to stay current on all his OC skills. Is that not true? (Asking as somebody who has no clue, but has been reading this thread out of curiosity.)

Not sure what "all his OC skills means". Of course breath continuously and never hold your breath is the golden rule in all diving. You actually have to determine your SAC (used throughout your calculations) using OC anyway. You also have to contingency plan your dive such that at the furthest/deepest point in the dive if you have to "bailout" you have a sufficiently sized bailout bottle and gas supply to get to the surface safely, considering all appropriate ascent issues. Outside of that it is necessary to exhale most of your breath into the counterlung before switching systems (unless the emergency itself precludes this, but it is necessary to help maintain stable buoyancy). Then you insert the OC regulator, purge, and begin your emergency ascent plan.

 

[caveseeker7]

Not sure what "all his OC skills means".

1) place 2nd stage in mouth
2) inhale
3) exhale
4) repeat 2) and 3) until returning to surface

• Reduction of equipment
• Reduction of weight, easier to manage

• 
  Don't know about those two.
  
  Rebreathers by definition are more equipment, basically at least a single tank OC setup plus the loop.
  Most rebreathers use two tanks and first stages, related hoses and valves.
  Most rebreathers, usually due to very limited onboard gas supply, require another setup for OC bailout.
  
  Weight varies quite a bit, too, and depends on what it is compared to.
  The OC gear I use weights in at 52 lbs, the RB weights 47 lbs. But by the time I add weights and bailout as necessary it's heavier ... and many rebreathers weight 20+ lbs more to start out with. Compared to twin 130s they usually look pretty good, though.
  
  Ease of use and handling also varies quite a bit between units. Some are considerably more involved than others, and certainly more involved than OC. Different units have different design envelops for different applications. Even when designed with the same goal in mind doesn't mean they're anything alike. Prime example are the Cis-Lunar MK-5p and the Halcyon RB80. Both designed specifically for deep cave exploration, both used very succesfully for just that, yet two units couldn't be any more different.

 

[DiverBuoy]

1) place 2nd stage in mouth
2) inhale
3) exhale
4) repeat 2) and 3) until returning to surface



Don't know about those two.

Rebreathers by definition are more equipment, basically at least a single tank OC setup plus the loop.
Most rebreathers use two tanks and first stages, related hoses and valves.
Most rebreathers, usually due to very limited onboard gas supply, require another setup for OC bailout.

Weight varies quite a bit, too, and depends on what it is compared to.
The OC gear I use weights in at 52 lbs, the RB weights 47 lbs. But by the time I add weights and bailout as necessary it's heavier ... and many rebreathers weight 20+ lbs more to start out with. Compared to twin 130s they usually look pretty good, though.

Ease of use and handling also varies quite a bit between units. Some are considerably more involved than others, and certainly more involved than OC. Different units have different design envelops for different applications. Even when designed with the same goal in mind doesn't mean they're anything alike. Prime example are the Cis-Lunar MK-5p and the Halcyon RB80. Both designed specifically for deep cave exploration, both used very succesfully for just that, yet two units couldn't be any more different.

I think it comes from the idea that if you were to compare say a remote dive spot with no dive shop where you planned nine dives on a bottle of O2 and a bottle of "gas" ... the OC guy would have to bring 9 bottles. Other than that agreed with assessment, it's relative. Same goes with the subjects really of deeper and longer ... given an abundance of the right equipment many things are "possible" even if not "practical". Cheers.

 

[DiverBuoy]

1) place 2nd stage in mouth
2) inhale
3) exhale
4) repeat 2) and 3) until returning to surface

1) place 2nd stage in mouth
1a) purge
2) inhale
3) exhale
3a) Precluding other emergency, with considerations for safety stops and decompression stops, proceed to step 4
4) repeat 2) and 3) until returning to surface