How deep to you dive on air diluent?

botle maker · 18th January 2008, 21:07

For me 30metres used He in Egypt on the Roslie Muller even at 7pence a litre it was cheap diving. I can see know point in paying for a dive not to remember it after. I never used to suffer from narcosis then I did a gas dive the difference for me was huge. I would not dive deeper than 40metres on OC in Britain without He, on CCR 30metres max. .

hoppyinca · 18th January 2008, 21:12

Quote: (Originally Posted by Beanie)

...Tx is cheap so I use it...

the decreased consumption of trimix was one of the main reasons I came to the dark side.

while 'running the numbers' and trying to 'standardize' my mixes for given depth ranges I planned on 165FSW | 50M as a max for air DIL...

the thing is, once the trimix in in the DIL tank, why not use it until it's gone? The only thing to watch is how the He will effect the required deco, too much will add significant and possibly unwanted deco and hypoxic mix when not dictated by the dive is silly IMHO, but in either of those cases just... DIL your DIL!

in summary, my deepest dive on CC with air DIL is 130FSW | ~40M.

my 2 cents...

hoppy

lizardland · 18th January 2008, 21:13

My deepest air dive on OC, 89m.

My deepest air dil dive on CCR, 28m. I use 18/40 for everything less than 60m, I never use air dil at all now. Less narcosis, less fatigue, less WOB, less stress on the scrubber.

Air dil is a bit like getting a Jaguar converted to run off chip fat. You could do it but why would you want to?

**Gill Envy** · 18th January 2008, 21:14

John, thanks for that, that's exactly the kind of feedback i'm looking for. I'll look into it more. I am TDI certified at this point and they do not have such a cert. that I am aware of...which might be problematic since the cross over would likely require redoing a bunch of stuff. i'll look into it.
thanks again.

g

Quote: (Originally Posted by jkaterenchuk)

You might want to look over the ANDI CCR program. Specifically, course TRD Level 3 - Technical Rebreather Diver Level 3. Link attached to the course standards.

Untitled Page

I just finished the course with Bruce Konefe in Thailand and its rated to 50MSW/164FSW and 30 Minutes of Deco only Air Diluent. I will be doing a detailed write up on the blow by blow for each dive on this course as well as a few others I took once I get a few spare hours. ANDI's program is indepth and ensures you are task loaded with valuable exercises in controlled conditions. It really starts to get you comfortable with many critical skills like SCR for extended periods.

Not sure if this fits the bill for what your are looking for but I thought I would mention it.

John

gerstl_ossi · 18th January 2008, 21:30

Diving a rebreather means less use of diluent. So why dive air on deeper dives. No cost of diving He-mix.
Max 30 - 40 meter in clear warm water. No air on cave dives.

Cheers Oswald

**Gill Envy** · 18th January 2008, 21:39

I'd like to respond publicly to a PM I got from a very considerate member who kindly qualified his concerns with the fact that he was not personally familiar with my dive style. He expressed caution around my use of the words "comfortable and confident".

Since others may be feeling this but not wanting to risk offense, I thought I just say a few words along those lines:

There is only so much one can ascertain about others diving styles from reading posts. concern is only natural as the words "comfortable and confident" relative terms and can be dangerous words to mix with rebreather diving. rest assured I have and will continue to take cautious baby steps as I venture deeper. I'm in no rush and am dually suspicious of my own assessment of my capabilities.

my pursuit of training is a reflection of that as I ascertain the safe limits of air diluent.

**Dave Sutton** · 18th January 2008, 21:41

Quote: (Originally Posted by diverklondike)

I almost ALWAYS have some "He" in my dil... The only exception is shallow oyster or quarry diving... Less than 75ft ffw.

It's amazing how much more you remember etc with a bit of "He" in the mix even on 100ft dives.

Dive Safe...

Mark

Concur with Mark. I draw the line at 100 feet. Normoxic trimix is a no brainer.

When I ran a chamber, we used to play in the thing and so we had lots of chamber time. I was *shocked* at the narcosis at 60 feet in a dry chamber. Take away the stimulus of being in the water and you can easially detect it. With that experience under my belt, I can feel it in the water also. So... why not have a clear head and remember what you're paying to see?

Dave

.

**Gill Envy** · 18th January 2008, 22:07

Thanks for the responses everyone. I figured I'd get questioned on my resistance to use helium but was most interested in the limits of air diluent. I trust that folks will keep weighing in on that even if I respond to why I'm resistant to Helium.

here goes

:

Decompression theory for N is a theory when applied to any individual.

PO2 tolerance is a theory when applied to any individual.

Decompression theory for He seems even more of a black art to me.

He is known to make one less tolerant of exercise post dive.

Adding a third set of theories of tolerances to the mix raises the task of risk assessment beyond my comfort zone for now. It also takes more than I feel is justified for what I do. Some even argue if a rebreather is overkill for what I do...I use all the same arguments for extended range recreational rebreather diving that folks use for He...not sure what that is telling me.
Having no more experience with He than taking hits off balloons as a kid to make funny noises may be part of the reason i'm still so leary...maybe I should call up my instructor and see if there is a safe way to try it without getting cirtified first. never mind, I didn't say that.

the diving I do:

I do a lot of shore diving. some of my favorite diving includes getting to and from the entry/exit point by kayak. I dive in strong currents. My desire to go deep is few and far between. the tropical destinations I like to go to tend to be particularly remote and with operations that have never catered to tec divers. Basically I like the freedom of deciding when, where, how long and how deep I'm going to dive. diving a rebreather was a natural step for someone who prefers such independence... though it certainly has it's down sides.

the long and short:
I do quite a bit of exertion pre and post dive, rebreather diving helps either to extend my bottom time and or limit my risk of dcs since I do limited or no deco. I'm concerned that He would increase my risk of getting bent with my level of exertion before, during and after the dive.

He is hard to get in remote locations.

the length of time I want to be deep is limited at this point.

the cost is not a concern.

ok, lay it on me:
additions and counters?

Mark Chase · 18th January 2008, 22:18

Quote: (Originally Posted by gerstl_ossi)

Diving a rebreather means less use of diluent. So why dive air on deeper dives. No cost of diving He-mix.
Max 30 - 40 meter in clear warm water. No air on cave dives.

Cheers Oswald

Because there are times when Trimix is not available.

When i dived the canyon they wouldn't give me trimix because i wasn't Mod 3 despite the fact i am TDI Mix on OC. Not a good excuse but its the truth.

When we did the Brothers gig there was no trimix available on the livaboard so we did 50-60m on air.

Obviously if mix was available we would have used it on a CCR as even at red sea costing its cheep.

I thought the question was how deep would you be willing to go on air?

When I have access to mix I use it all the time. I did a 25m dive last Saturday on 18/45.

ATB

Mark

Mark Chase · 18th January 2008, 22:32

Quote: (Originally Posted by Gill Envy)

Thanks for the responses everyone. I figured I'd get questioned on my resistance to use helium but was most interested in the limits of air diluent. I trust that folks will keep weighing in on that even if I respond to why I'm resistant to Helium.

here goes

:

Decompression theory for N is a theory when applied to any individual.

PO2 tolerance is a theory when applied to any individual.

Decompression theory for He seems even more of a black art to me.

He is known to make one less tolerant of exercise post dive.

Adding a third set of theories of tolerances to the mix raises the task of risk assessment beyond my comfort zone for now. It also takes more than I feel is justified for what I do. Some even argue if a rebreather is overkill for what I do...I use all the same arguments for extended range recreational rebreather diving that folks use for He...not sure what that is telling me.
Having no more experience with He than taking hits off balloons as a kid to make funny noises may be part of the reason i'm still so leary...maybe I should call up my instructor and see if there is a safe way to try it without getting cirtified first. never mind, I didn't say that.

the diving I do:

I do a lot of shore diving. some of my favorite diving includes getting to and from the entry/exit point by kayak. I dive in strong currents. My desire to go deep is few and far between. the tropical destinations I like to go to tend to be particularly remote and with operations that have never catered to tec divers. Basically I like the freedom of deciding when, where, how long and how deep I'm going to dive. diving a rebreather was a natural step for someone who prefers such independence... though it certainly has it's down sides.

the long and short:
I do quite a bit of exertion pre and post dive, rebreather diving helps either to extend my bottom time and or limit my risk of dcs since I do limited or no deco. I'm concerned that He would increase my risk of getting bent with my level of exertion before, during and after the dive.

He is hard to get in remote locations.

the length of time I want to be deep is limited at this point.

the cost is not a concern.

ok, lay it on me:
additions and counters?

I am 44 a smoker, a drinker, 2.5 stone over weight and not very fit in any other way. I dive loads of helium (usualy max 25END) running zero safety on Vr3 and 10/90 on The GF Shearwater. I have dived in cold water and in strong currents where your holding on the deco line like a flag. I often dive for 120-180mins runs on dives up to 80m and very ocasionaly beyound and I have been lucky enough not to have had a proper bend on mix yet.

I have dived 70m on air OC and 65m on air CCR. Deep air in the right conditions is not a no no for me, its just that Mix is so cheep on CCR then why the hell not.

In July this year ill have been a diver for 20 years.

So my 2p is, getting bent is nothing to do with He content and everything to do with the individual person on the day and the profile he /she decided to use.

The second point Id make is I have witnessed four or five Helium bends. They were all fixed with Ambient 02 on the boat. All the Nitrogen bends I have seen needed hyperbaric treatment.

Is helium better than Air? No definitly not.

Helium makes rapid ascents far more dangerous than Air does.

However i feel the advantages of a clear head deep far outweigh the posabuility of me having a rapid ascent.

ATB

Mark

18th January 2008, 21:07	#11 (permalink)
botle maker New Member Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Oct 2005 Location: bletchley bucks uk Posts: 22	Re: How deep to you dive on air diluent? For me 30metres used He in Egypt on the Roslie Muller even at 7pence a litre it was cheap diving. I can see know point in paying for a dive not to remember it after. I never used to suffer from narcosis then I did a gas dive the difference for me was huge. I would not dive deeper than 40metres on OC in Britain without He, on CCR 30metres max. .
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18th January 2008, 21:12	#12 (permalink)
hoppyinca New Member Current Rebreather/s: MK 15.X Other Rebreather/s: Join Date: Jun 2005 Location: Laguna Niguel, CA USA Posts: 252	Re: How deep to you dive on air diluent? Quote: (Originally Posted by Beanie) ...Tx is cheap so I use it... the decreased consumption of trimix was one of the main reasons I came to the dark side. while 'running the numbers' and trying to 'standardize' my mixes for given depth ranges I planned on 165FSW \| 50M as a max for air DIL... the thing is, once the trimix in in the DIL tank, why not use it until it's gone? The only thing to watch is how the He will effect the required deco, too much will add significant and possibly unwanted deco and hypoxic mix when not dictated by the dive is silly IMHO, but in either of those cases just... DIL your DIL! in summary, my deepest dive on CC with air DIL is 130FSW \| ~40M. my 2 cents... hoppy __________________ "The government is merely a servant... merely a temporary servant; it cannot be its prerogative to determine what is right and what is wrong, and decide who is a patriot and who isn't. Its function is to obey orders, not originate them..." - Mark Twain
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18th January 2008, 21:13	#13 (permalink)
lizardland Yak Current Rebreather/s: MK 15.X Home Build Other Rebreather/s: Classic Kiss Home Build Join Date: Mar 2005 Location: North... Posts: 1,304	Re: How deep to you dive on air diluent? My deepest air dive on OC, 89m. My deepest air dil dive on CCR, 28m. I use 18/40 for everything less than 60m, I never use air dil at all now. Less narcosis, less fatigue, less WOB, less stress on the scrubber. Air dil is a bit like getting a Jaguar converted to run off chip fat. You could do it but why would you want to? __________________ Can you imagine drifting along in the sea with your mouth open and a load of f***ing plankton going in? You'd like it, would you? www.westons-cider.co.uk Azerbaijani Association of Technical Divers Publicity Officer and Goat Wrangler
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18th January 2008, 21:14	#14 (permalink)
Gill Envy Shearwater Copis Divers Current Rebreather/s: Other CCR Other Rebreather/s: Evolution Other CCR Join Date: Nov 2005 Location: seattle Posts: 1,314	Re: How deep to you dive on air diluent? John, thanks for that, that's exactly the kind of feedback i'm looking for. I'll look into it more. I am TDI certified at this point and they do not have such a cert. that I am aware of...which might be problematic since the cross over would likely require redoing a bunch of stuff. i'll look into it. thanks again. g Quote: (Originally Posted by jkaterenchuk) You might want to look over the ANDI CCR program. Specifically, course TRD Level 3 - Technical Rebreather Diver Level 3. Link attached to the course standards. Untitled Page I just finished the course with Bruce Konefe in Thailand and its rated to 50MSW/164FSW and 30 Minutes of Deco only Air Diluent. I will be doing a detailed write up on the blow by blow for each dive on this course as well as a few others I took once I get a few spare hours. ANDI's program is indepth and ensures you are task loaded with valuable exercises in controlled conditions. It really starts to get you comfortable with many critical skills like SCR for extended periods. Not sure if this fits the bill for what your are looking for but I thought I would mention it. John __________________ Gill Envy ...Because I wasn't born with gills! ><(°>><(°>><(°>><(°>><(°>><(°>><(°>><(°>
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18th January 2008, 21:30	#15 (permalink)
gerstl_ossi Custom Title Allowed! Current Rebreather/s: RB80 / Clone Home Build Other Rebreather/s: Not Bought Yet RB80 / Clone Home Build Join Date: Dec 2006 Location: Italy Posts: 337	Re: How deep to you dive on air diluent? Diving a rebreather means less use of diluent. So why dive air on deeper dives. No cost of diving He-mix. Max 30 - 40 meter in clear warm water. No air on cave dives. Cheers Oswald Last edited by gerstl_ossi : 18th January 2008 at 21:44.
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18th January 2008, 21:39	#16 (permalink)
Gill Envy Shearwater Copis Divers Current Rebreather/s: Other CCR Other Rebreather/s: Evolution Other CCR Join Date: Nov 2005 Location: seattle Posts: 1,314	Re: How deep to you dive on air diluent? I'd like to respond publicly to a PM I got from a very considerate member who kindly qualified his concerns with the fact that he was not personally familiar with my dive style. He expressed caution around my use of the words "comfortable and confident". Since others may be feeling this but not wanting to risk offense, I thought I just say a few words along those lines: There is only so much one can ascertain about others diving styles from reading posts. concern is only natural as the words "comfortable and confident" relative terms and can be dangerous words to mix with rebreather diving. rest assured I have and will continue to take cautious baby steps as I venture deeper. I'm in no rush and am dually suspicious of my own assessment of my capabilities. my pursuit of training is a reflection of that as I ascertain the safe limits of air diluent. __________________ Gill Envy ...Because I wasn't born with gills! ><(°>><(°>><(°>><(°>><(°>><(°>><(°>><(°>
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18th January 2008, 21:41	#17 (permalink)
Dave Sutton Diveshop of Horrors Current Rebreather/s: Sport Kiss MK 15.X rEvo Other CCR Azimuth Home Build Other Rebreather/s: Classic Kiss rEvo Other CCR Azimuth Home Build Join Date: Jun 2006 Location: Narragansett, Rhode Island and Hackettstown, New Jersey Posts: 2,672	Re: How deep to you dive on air diluent? Quote: (Originally Posted by diverklondike) I almost ALWAYS have some "He" in my dil... The only exception is shallow oyster or quarry diving... Less than 75ft ffw. It's amazing how much more you remember etc with a bit of "He" in the mix even on 100ft dives. Dive Safe... Mark Concur with Mark. I draw the line at 100 feet. Normoxic trimix is a no brainer. When I ran a chamber, we used to play in the thing and so we had lots of chamber time. I was shocked at the narcosis at 60 feet in a dry chamber. Take away the stimulus of being in the water and you can easially detect it. With that experience under my belt, I can feel it in the water also. So... why not have a clear head and remember what you're paying to see? Dave . __________________ "Changes in Lattitudes, Changes in Attitudes, Nothing remains quite the same".... www.nobubblediving.com
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18th January 2008, 22:07	#18 (permalink)
Gill Envy Shearwater Copis Divers Current Rebreather/s: Other CCR Other Rebreather/s: Evolution Other CCR Join Date: Nov 2005 Location: seattle Posts: 1,314	Re: How deep to you dive on air diluent? Thanks for the responses everyone. I figured I'd get questioned on my resistance to use helium but was most interested in the limits of air diluent. I trust that folks will keep weighing in on that even if I respond to why I'm resistant to Helium. here goes: Decompression theory for N is a theory when applied to any individual. PO2 tolerance is a theory when applied to any individual. Decompression theory for He seems even more of a black art to me. He is known to make one less tolerant of exercise post dive. Adding a third set of theories of tolerances to the mix raises the task of risk assessment beyond my comfort zone for now. It also takes more than I feel is justified for what I do. Some even argue if a rebreather is overkill for what I do...I use all the same arguments for extended range recreational rebreather diving that folks use for He...not sure what that is telling me. Having no more experience with He than taking hits off balloons as a kid to make funny noises may be part of the reason i'm still so leary...maybe I should call up my instructor and see if there is a safe way to try it without getting cirtified first. never mind, I didn't say that. the diving I do: I do a lot of shore diving. some of my favorite diving includes getting to and from the entry/exit point by kayak. I dive in strong currents. My desire to go deep is few and far between. the tropical destinations I like to go to tend to be particularly remote and with operations that have never catered to tec divers. Basically I like the freedom of deciding when, where, how long and how deep I'm going to dive. diving a rebreather was a natural step for someone who prefers such independence... though it certainly has it's down sides. the long and short: I do quite a bit of exertion pre and post dive, rebreather diving helps either to extend my bottom time and or limit my risk of dcs since I do limited or no deco. I'm concerned that He would increase my risk of getting bent with my level of exertion before, during and after the dive. He is hard to get in remote locations. the length of time I want to be deep is limited at this point. the cost is not a concern. ok, lay it on me: additions and counters? __________________ Gill Envy ...Because I wasn't born with gills! ><(°>><(°>><(°>><(°>><(°>><(°>><(°>><(°>
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18th January 2008, 22:18	#19 (permalink)
Mark Chase I go down for ages Current Rebreather/s: Classic Kiss Other Rebreather/s: Inspiration Classic Join Date: Jan 2005 Location: Kent Posts: 2,700	Re: How deep to you dive on air diluent? Quote: (Originally Posted by gerstl_ossi) Diving a rebreather means less use of diluent. So why dive air on deeper dives. No cost of diving He-mix. Max 30 - 40 meter in clear warm water. No air on cave dives. Cheers Oswald Because there are times when Trimix is not available. When i dived the canyon they wouldn't give me trimix because i wasn't Mod 3 despite the fact i am TDI Mix on OC. Not a good excuse but its the truth. When we did the Brothers gig there was no trimix available on the livaboard so we did 50-60m on air. Obviously if mix was available we would have used it on a CCR as even at red sea costing its cheep. I thought the question was how deep would you be willing to go on air? When I have access to mix I use it all the time. I did a 25m dive last Saturday on 18/45. ATB Mark __________________ Is it supposed to make that noise ? I took my unit to the dive shop and demanded they bolt on every thing that would fit. Join my elite diving teem and get a Tshirt "Doing It Chasey"Hammerhead Eccr Advanced Diving System
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18th January 2008, 22:32	#20 (permalink)
Mark Chase I go down for ages Current Rebreather/s: Classic Kiss Other Rebreather/s: Inspiration Classic Join Date: Jan 2005 Location: Kent Posts: 2,700	Re: How deep to you dive on air diluent? Quote: (Originally Posted by Gill Envy) Thanks for the responses everyone. I figured I'd get questioned on my resistance to use helium but was most interested in the limits of air diluent. I trust that folks will keep weighing in on that even if I respond to why I'm resistant to Helium. here goes: Decompression theory for N is a theory when applied to any individual. PO2 tolerance is a theory when applied to any individual. Decompression theory for He seems even more of a black art to me. He is known to make one less tolerant of exercise post dive. Adding a third set of theories of tolerances to the mix raises the task of risk assessment beyond my comfort zone for now. It also takes more than I feel is justified for what I do. Some even argue if a rebreather is overkill for what I do...I use all the same arguments for extended range recreational rebreather diving that folks use for He...not sure what that is telling me. Having no more experience with He than taking hits off balloons as a kid to make funny noises may be part of the reason i'm still so leary...maybe I should call up my instructor and see if there is a safe way to try it without getting cirtified first. never mind, I didn't say that. the diving I do: I do a lot of shore diving. some of my favorite diving includes getting to and from the entry/exit point by kayak. I dive in strong currents. My desire to go deep is few and far between. the tropical destinations I like to go to tend to be particularly remote and with operations that have never catered to tec divers. Basically I like the freedom of deciding when, where, how long and how deep I'm going to dive. diving a rebreather was a natural step for someone who prefers such independence... though it certainly has it's down sides. the long and short: I do quite a bit of exertion pre and post dive, rebreather diving helps either to extend my bottom time and or limit my risk of dcs since I do limited or no deco. I'm concerned that He would increase my risk of getting bent with my level of exertion before, during and after the dive. He is hard to get in remote locations. the length of time I want to be deep is limited at this point. the cost is not a concern. ok, lay it on me: additions and counters? I am 44 a smoker, a drinker, 2.5 stone over weight and not very fit in any other way. I dive loads of helium (usualy max 25END) running zero safety on Vr3 and 10/90 on The GF Shearwater. I have dived in cold water and in strong currents where your holding on the deco line like a flag. I often dive for 120-180mins runs on dives up to 80m and very ocasionaly beyound and I have been lucky enough not to have had a proper bend on mix yet. I have dived 70m on air OC and 65m on air CCR. Deep air in the right conditions is not a no no for me, its just that Mix is so cheep on CCR then why the hell not. In July this year ill have been a diver for 20 years. So my 2p is, getting bent is nothing to do with He content and everything to do with the individual person on the day and the profile he /she decided to use. The second point Id make is I have witnessed four or five Helium bends. They were all fixed with Ambient 02 on the boat. All the Nitrogen bends I have seen needed hyperbaric treatment. Is helium better than Air? No definitly not. Helium makes rapid ascents far more dangerous than Air does. However i feel the advantages of a clear head deep far outweigh the posabuility of me having a rapid ascent. ATB Mark __________________ Is it supposed to make that noise ? I took my unit to the dive shop and demanded they bolt on every thing that would fit. Join my elite diving teem and get a Tshirt "Doing It Chasey"Hammerhead Eccr Advanced Diving System
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