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CPTOZZY
05-03-2008, 16:56
I'm curious about rebreathers.
I really know next to nothing about them. I assume they use Soda Lime to "scrub" the Carbon out of the CO2 which allows the oxygen to be recycled. Is this correct?

What are the Benefits of Rebreathers? What Are the risks?

I heard they were "Killers", but more and more people seem to be diving them so there must be a greater benefit verses risk......??

Here is a funny Video I found , but I really would like some info on Rebreathers.

YouTube - How Not To Use a Rebreather (http://www.youtube.com/watch?v=GhvHTHLg418&feature=related)

thanks

wolfen42
05-03-2008, 17:24
From my reading... :)
Rebreathers will kill you if you aren't willing to make absolutely sure that yours is working BEFORE you get in the water. They will also kill you if you try to reuse your material by repacking it. They will also kill you if you try to use them at a shallow depth without correctly setting them up for it.

Essentially, they allow you a lot more flexibility but require more attention and care on your part. A lot more.

Charles R
05-03-2008, 19:13
I would suggest alot of reading here Rebreather Forums - Rebreather World (http://www.rebreatherworld.com/forums.php) there are so many diferent types of rebreathers and this kind of information is best left to the experts.

ianr33
05-03-2008, 20:10
I'm curious about rebreathers.
I really know next to nothing about them. I assume they use Soda Lime to "scrub" the Carbon out of the CO2 which allows the oxygen to be recycled. Is this correct?

thanks

Not quite.

The Soda Lime (Calcium Oxide) combines with the CO2 to form Calcium Carbonate CaO+CO2 --> CaCO3

As your body uses Oxygen more has to be added .

A rebreather has 3 main parts. A Diluent Tank,an Oxygen Tank and a Scrubber.
The Diluent dilutes the oxygen (you can not breathe pure O2 below 20 feet)The Diluent can be air,nitrox or trimix depending on depth
The Oxygen tank adds oxygen as needed and the scrubber removes the CO2.

The danger of a rebreather is that if the PO2 drops below about .18ATM you can lose consciousness and drown. If the PO2 goes above about 1.6ATM you can have an Oxygen Toxicity seizure and again you will most likely drown.

The advantages are
1)Possible to do dives that can not be done on regular scuba.Want to do 300 feet for an hour? Do it on a rebreather as it would not be possible to carry enough tanks on Open Circuit
2)They use very little gas.Helium is expensive and doing a deep trimix dive can cost $$$$ on Open Circuit
3)The gas being breathed is warm and moist
4)No bubbles,good for photography

elijahb
05-03-2008, 22:10
I'm curious about rebreathers.
I really know next to nothing about them. I assume they use Soda Lime to "scrub" the Carbon out of the CO2 which allows the oxygen to be recycled. Is this correct?

thanks

Not quite.

The Soda Lime (Calcium Oxide) combines with the CO2 to form Calcium Carbonate CaO+CO2 --> CaCO3

As your body uses Oxygen more has to be added .

A rebreather has 3 main parts. A Diluent Tank,an Oxygen Tank and a Scrubber.
The Diluent dilutes the oxygen (you can not breathe pure O2 below 20 feet)The Diluent can be air,nitrox or trimix depending on depth
The Oxygen tank adds oxygen as needed and the scrubber removes the CO2.

The danger of a rebreather is that if the PO2 drops below about .18ATM you can lose consciousness and drown. If the PO2 goes above about 1.6ATM you can have an Oxygen Toxicity seizure and again you will most likely drown.

The advantages are
1)Possible to do dives that can not be done on regular scuba.Want to do 300 feet for an hour? Do it on a rebreather as it would not be possible to carry enough tanks on Open Circuit
2)They use very little gas.Helium is expensive and doing a deep trimix dive can cost $$$$ on Open Circuit
3)The gas being breathed is warm and moist
4)No bubbles,good for photography
wow lots of good information
Anyone know how much a rebreather would cost.
Sounds like it would cost a lot because of all the chemistry involved.

ianr33
05-03-2008, 22:21
Anyone know how much a rebreather would cost.
Sounds like it would cost a lot because of all the chemistry involved.

Somewhere in the range $5-10,000 depending on the model.

Plus probably around another $3000 for all the training required to dive them to Hypoxic Trimix depths (>200 feet)

Its not a cheap game.

Some popular rebreathers.
Kiss KISS MANUFACTURING (http://www.kissrebreathers.com/)
Megalodon InnerSpace Systems Corp (http://www.customrebreathers.com/)
Inspiration Ambient Pressure Diving Ltd. (http://www.apdiving.com/flash_content/flash_content.html)

Rebreather World - Rebreathers for Scuba Diving - the next step (http://www.rebreatherworld.com) is the place to learn more about rebreathers than you ever wanted to know

terrillja
05-03-2008, 22:21
Low end manual CCR, maybe 5K, electronic CCR, 7K or so, the evolution and inspiration, which are some of the more popular models are both 10K.

Roughly $500 a yr for maintenance.

Personally, I like how with OC I know my mix, and all its characteristics, MOD, all that, and it doesn't change. The RB is always changing the mix, if something jambs, you are SOL unless you can get to OC bailout. Just not for me.

texdiveguy
05-03-2008, 22:44
You have been provided some of the basics in the posts above....much more to CCR than meets the eye.....for a person wishing to get a bit more info. a good source of data, though a bit 'dated' in terms of branding/gear to some degree but in procedural data still a great read is : Mastering Rebreathers. CCR has come along way over recent years and in particular that area that focuses on us the recreational diver, but still has lots to offer in terms of future applications and gear. Rebreathers are still a rare bird in most diving circles even today....OC still is and will be the dominate means of diving for sometime to come.

texdiveguy
05-03-2008, 22:49
Some popular rebreathers.
Kiss KISS MANUFACTURING (http://www.kissrebreathers.com/)
Megalodon InnerSpace Systems Corp (http://www.customrebreathers.com/)
Inspiration Ambient Pressure Diving Ltd. (http://www.apdiving.com/flash_content/flash_content.html)



SCUBA Diving Equipment for Technical, Wreck and Cave Diving: Dive Rite, Inc - Product Catalog - O2ptima FX Rebreather (http://www.diverite.com/products/catalog/o2ptima/drt-1-fx)

ianr33
05-03-2008, 23:27
I could maybe see buying a rebreather sometime in the future.Maybe!

What would I use it for? Well I have a love affair with the walls on Cayman. Deepest I have been there is 210. I could see doing a brief dive to maybe 300 feet oneday,anything beyond that is rebreather territory.

And if anybody thinks there is nothing to see deep,well,you are wrong! 200 feet is about where the corals stop and the sponges take over.Big sponges!

Black-Gorrilla
05-04-2008, 03:22
(ignore this)

texdiveguy
05-04-2008, 10:11
I could maybe see buying a rebreather sometime in the future.Maybe!

What would I use it for? Well I have a love affair with the walls on Cayman. Deepest I have been there is 210. I could see doing a brief dive to maybe 300 feet oneday,anything beyond that is rebreather territory.

And if anybody thinks there is nothing to see deep,well,you are wrong! 200 feet is about where the corals stop and the sponges take over.Big sponges!

Heck, I would love to hit those walls at those depths, and down below 300FSW in Cayman....my problem is I have never even been to Cayman :( . I just have to wish for a trip someday... and enjoy the photos from others for now!

ianr33
05-04-2008, 11:10
I was there last Thanksgiving. Talking to one of their Instructors,Natt he said he did a 300 foot dive about once a week,deepest ever 450 feet.

Incidentally diving with a guy on a rebreather makes for easy contingency planning. If anything goes wrong just steal the rebreather guys bail out!

Getting a job with Divetech would be a GREAT second career !!

The walls are just amazing. Something very special about being at 200 feet ,seeing the sun looking up and HUGE sponges,100? 200?? feet below .

texdiveguy
05-04-2008, 11:39
I was there last Thanksgiving. Talking to one of their Instructors,Natt he said he did a 300 foot dive about once a week,deepest ever 450 feet.

Incidentally diving with a guy on a rebreather makes for easy contingency planning. If anything goes wrong just steal the rebreather guys bail out!

Getting a job with Divetech would be a GREAT second career !!

The walls are just amazing. Something very special about being at 200 feet ,seeing the sun looking up and HUGE sponges,100? 200?? feet below .

That is so awesome....I am jealous!!!! Sounds so relaxing. :)

Yea I have heard such great things about Divetech ..... sounds like a wonderful operation with an eye on safety and detail...def. would be the op I would dive with.

Its on my 'wish' list for sure....Cayman!

ianr33
05-04-2008, 11:51
One of the great things about Divetech is that you can dive as deep as you want and do it from shore!

A set of Al 80' doubles with 20/25,an 80 of 32% and 40 of 80% for deco was less than $100 (and about the same price as a 2 tank recreational boat trip)

Do 20 minutes at 200 feet where the wall is going dead vertical,come up a 45 degree slope of pristine corals to the first switch at 130, head back over sand flats at around 60 feet to the "mini wall" which runs from around 50 feet to 25 feet. A perfect profile and just wonderful diving.

You should try it sometime. Its not far from Texas !!

I'm going back in September this year for Tekweek Scuba Gear and Scuba Diving Equipment - Discount dive gear (Cheap online!) (http://Tekweek)

Might even get to try one of those rebreathers :smiley20:

texdiveguy
05-04-2008, 12:00
One of the great things about Divetech is that you can dive as deep as you want and do it from shore!

A set of Al 80' doubles with 20/25,an 80 of 32% and 40 of 80% for deco was less than $100 (and about the same price as a 2 tank recreational boat trip)

Do 20 minutes at 200 feet where the wall is going dead vertical,come up a 45 degree slope of pristine corals to the first switch at 130, head back over sand flats at around 60 feet to the "mini wall" which runs from around 50 feet to 25 feet. A perfect profile and just wonderful diving.

You should try it sometime. Its not far from Texas !!

I'm going back in September this year for Tekweek Scuba Gear and Scuba Diving Equipment - Discount dive gear (Cheap online!) (http://Tekweek)

Might even get to try one of those rebreathers :smiley20:

This is torture reading about this and sitting here at my 'dusty desk' in Arlington--LOL!!!

So what does TekWeek involve....have you done that event before.....I have only read promo pieces on it....does sound interesting..?

Deep walls from shore...dang what more could you want for $100 (are those standard pre mixed combo's they have set up for that cost?) -- :)

ianr33
05-04-2008, 12:06
[quote=ianr33;168053]

So what does TekWeek involve....have you done that event before.....I have only read promo pieces on it....does sound interesting..?


My first time.

Daily boat dive to 200 feet for us normoxic weenies. Much deeper for rebreather gods.

As much shallow shore diving as you can handle,lots of good food, lots of toys to look at and maybe try out.

One big diving party.

I cant wait !

CPTOZZY
05-04-2008, 18:10
I'm curious about rebreathers.
I really know next to nothing about them. I assume they use Soda Lime to "scrub" the Carbon out of the CO2 which allows the oxygen to be recycled. Is this correct?

thanks

Not quite.

The Soda Lime (Calcium Oxide) combines with the CO2 to form Calcium Carbonate CaO+CO2 --> CaCO3

As your body uses Oxygen more has to be added .

A rebreather has 3 main parts. A Diluent Tank,an Oxygen Tank and a Scrubber.
The Diluent dilutes the oxygen (you can not breathe pure O2 below 20 feet)The Diluent can be air,nitrox or trimix depending on depth
The Oxygen tank adds oxygen as needed and the scrubber removes the CO2.

The danger of a rebreather is that if the PO2 drops below about .18ATM you can lose consciousness and drown. If the PO2 goes above about 1.6ATM you can have an Oxygen Toxicity seizure and again you will most likely drown.

The advantages are
1)Possible to do dives that can not be done on regular scuba.Want to do 300 feet for an hour? Do it on a rebreather as it would not be possible to carry enough tanks on Open Circuit
2)They use very little gas.Helium is expensive and doing a deep trimix dive can cost $$$$ on Open Circuit
3)The gas being breathed is warm and moist
4)No bubbles,good for photography


thanks for the Info -- A couple of more questions:

1) Is the benefit due soley because of the reduction in bulk

("Want to do 300 feet for an hour? Do it on a rebreather as it would not be possible to carry enough tanks on Open Circuit")

or is there a reduction in deco obligation with CCR's?

2) I've heard about the need for Open Circuit "Bailout" with CCR's. is this a built in feature, an additional open circuit "spare Air" or what?? (What about Deco?)

Thanks Again

ianr33
05-04-2008, 19:29
e of more questions:

1) Is the benefit due soley because of the reduction in bulk

("Want to do 300 feet for an hour? Do it on a rebreather as it would not be possible to carry enough tanks on Open Circuit")

or is there a reduction in deco obligation with CCR's?

2) I've heard about the need for Open Circuit "Bailout" with CCR's. is this a built in feature, an additional open circuit "spare Air" or what?? (What about Deco?)

Thanks Again

1) Mainly the reduction in bulk.
On a level profile the deco on a rebreather will be roughly the same as open circuit using an optimium botom mix. On a gradually ascending profile the deco will be less on the rebreather. (Because the pO2 can be kept at 1.2ATM or whatever is chosen throughout the dive)

2)Open Circuit Bailout tanks are regular scuba tanks each with its own regulator. (Like a pony tank) For an NDL dive to less than say,100 feet a single Al 40 with air would be fine. For deeper dives at least 2 bailout tanks would be carried,one a mix that is breathable on the bottom,the other a deco mix. So even though the rebreather may be fairly compact the extra tanks needed to get you back to the surface in the event of a rebreather failure can be significant.

On a big dive bailout will probably be shared between teams e.g if the bailout plan requires 3 tanks each diver will carry 2 (a bottom mix and a deco mix) in the event of a problem tanks can be shuffled around.

CPTOZZY
05-05-2008, 06:31
e of more questions:

1) Is the benefit due soley because of the reduction in bulk

("Want to do 300 feet for an hour? Do it on a rebreather as it would not be possible to carry enough tanks on Open Circuit")

or is there a reduction in deco obligation with CCR's?

2) I've heard about the need for Open Circuit "Bailout" with CCR's. is this a built in feature, an additional open circuit "spare Air" or what?? (What about Deco?)

Thanks Again

1) Mainly the reduction in bulk.
On a level profile the deco on a rebreather will be roughly the same as open circuit using an optimium botom mix. On a gradually ascending profile the deco will be less on the rebreather. (Because the pO2 can be kept at 1.2ATM or whatever is chosen throughout the dive)

2)Open Circuit Bailout tanks are regular scuba tanks each with its own regulator. (Like a pony tank) For an NDL dive to less than say,100 feet a single Al 40 with air would be fine. For deeper dives at least 2 bailout tanks would be carried,one a mix that is breathable on the bottom,the other a deco mix. So even though the rebreather may be fairly compact the extra tanks needed to get you back to the surface in the event of a rebreather failure can be significant.

On a big dive bailout will probably be shared between teams e.g if the bailout plan requires 3 tanks each diver will carry 2 (a bottom mix and a deco mix) in the event of a problem tanks can be shuffled around.

Great information !! Thank you