What's a rebreather?

[caveseeker7]

If you can damage your ears on open circuit you can damage them on closed circuit. Did she mention why any of this would be different on a rebreather?

Mind you, I'm neither a doc nor a nurse. Just a diver with ears and a rebreather.

 

[Warren_L]

Caveseeker's right. While diving, a rebreather shouldn't make much of a difference as far as being able to equalize. If you have trouble equalizing on open circuit, a rebreather isn't going to necessarily be any better or worse. Someone referred to problems after diving on a rebreather - that can certainly happen. If you're breathing oxygen rich mixes (which can happen with CCRs and deco diving on OC), your inner ear will equalize with these high mixes. After a dive, if the high mixes are still in your inner ear and sinuses, you may have to continue to equalize for a while after the dive as the oxygen can get slowly metabolized through the skin and membranes in your inner ear. As this happens, there can be a slow decline in pressure, resulting in a bit of a squeeze if left unequalized.

I'm no doc either. Just another guy with a rebreather.

 

[wedivebc]

never mind

 

[Jupiter31]

OK...don't make fun of me, please.....this is a term I've not heard until visiting this board.

What's a rebreather?

Please don't laugh at me.......but, this isn't something we covered in the class! :11:

Big Hugs~

Alix

Bet you never expected all the replies, especailly for a very fair question -

I've been diving almost 30 years, and while its neat technology, I never saw the need, not because its "dangerous" but because of the cost.

Unless you have a real desire to have the latest and the greatest (someone spent 20k++ to have the 1st plasma 60" TV), are super technically oriented - and willing to do the maintenance required, or are a serious photog wanting to virtually eliminate bubbles - these may not be the breathing devise for you. And I realize your question was "what are these things", not that you are planning to buy one.

I don't think they are for the average diver, and certainly not for a beginner. The inital usage was military - mission critical when stealth was needed.

That said, I would consider one if the maintenance issues and pricing could be "solved" - until then about as technical as I'm likely to get is a 119 steel w/ 36 o2!

Good luck and welcome to the board.

 

[Mverick]

Bet you never expected all the replies, especailly for a very fair question -

I've been diving almost 30 years, and while its neat technology, I never saw the need, not because its "dangerous" but because of the cost.

Unless you have a real desire to have the latest and the greatest (someone spent 20k++ to have the 1st plasma 60" TV), are super technically oriented - and willing to do the maintenance required, or are a serious photog wanting to virtually eliminate bubbles - these may not be the breathing devise for you. And I realize your question was "what are these things", not that you are planning to buy one.

I don't think they are for the average diver, and certainly not for a beginner. The inital usage was military - mission critical when stealth was needed.

That said, I would consider one if the maintenance issues and pricing could be "solved" - until then about as technical as I'm likely to get is a 119 steel w/ 36 o2!

Good luck and welcome to the board.

I agree the price is high. But, when doing technical labled dives with Helium oc gets pricey. With the RB I fill my DIL tank which costs me about $10 and have my bailout tanks filled which costs around $120. And as long as I don't have a Problem the bailout tanks don't get used. So, every time I dive it cost's me around $30 or so with sorb and tanks for dives that used to cost around $300 for gas. Plus, I have a window of 6 hours on the RB that I didn't have on OC gas.

Do 50 dives a year at $300 a dive and that's $15000. Do 50 dives a year on the RB and that's $1500. You can see where the RB comes into it's own. In the first year you paid for the RB and training.

To me it was about cost savings on gas and Safety. Safety as if I get my butt lost in a deep wreck I have a while to figure it out. Where if I get lost in a deep wreck on OC I need to get it worked out quickly.

Your depth has a lot to do with you're time underwater on OC. On RB's it doesn't. Meaning gas that will last you 1 hour at 30 feet only lasts you 2 min at depth. While on a RB gas that lasts you 1 hour at 30feet lasts you 1 hour at depth.

Some people also want them just because there cool. LOL But there are reasons for them.

 

[Starboard Tack]

Hey Mverick,

And actually all of you guys, Caveseeker, Warren L, and wedivebc. I have really enjoyed this thread. I am just getting started on a Draeger and the last post has me wondering about sodasorb, or whichever brand you use on CC. How long does it last and how do you know how long you have left. I haven't dove my Draeger yet. I just ordered the connections for my VR3 and will start diving it once I have the electronics straightened out and take the class. I'm just curious about other systems.

Thanks,
Mike

 

[caveseeker7]

Hi Mike, thanks for the feedback.

Regarding your question, most manufacturers test, rate and recommend one absorbent.
For example for the Inspiration it is Sofnolime 797, for the PRISM Topaz it's Sodasorb 6-12 and for the Dräger you're planning to dive it's Dräger's own DiveSorb. Since the Dräger has CE testing and certification the unit is rated accordingly. The details of the Dräger's rating are available from Aqualung/Dräger's download library.

Once you dive with rebreather you'll keep track of the time you use it.
Hence it's fairly easy to track the scrubber usage as well as the highly recommended
O2 sensor (or sensors, and batteries on CCRs).

How exactly to handle sorb, track times etc will be part of your rebreather class.

Safe diving
Stefan

 

[Warren_L]

How long scrubber will last depends greatly on a number of factors. Keep in mind, not all rebreathers will have the same sized scrubber basket as well. My evolution holds about 4.5lbs of Sofnolime (I use 812 mesh) and I've gotten 4 hours on a fill. Your metabolism (which is affected by workload) plays a big role as well, since the more you work, the more you produce CO2 and that will shorten your scrubber life. Mesh size can also play a role - smaller mesh (higher number) will be able to scrub more CO2 due to greater surface area, however, generally at the cost of work of breathing.

If you're starting off, as Caveseeker alludes to, I would go with the manufacturer's recommendation and make changes as necessary.

 

[Dr. Doug Ebersole]

I agree with everything above. Also remember scrubbers works on a chemical reaction that is temperature-dependent so they are less efficient in cold waters like where WarrenL and Caveseeker7 live and more efficient where the warm water wussies like me live. Damn that high school chemistry!

Anyway, all of this will be covered in your course.

Doug

 

[Starboard Tack]

Thanks much, all. I'm looking forward to the closeups with the locals.