Diluent / Bail-out / Deco Line gas choice

Drmike · 13th June 2007, 13:02

Ill chime in with my opinion/advice if you pay me what you should be paying for the CCR trimix course you should be doing

but sorry cant supply a cert.
:P

Drmike · 13th June 2007, 13:11

Quote: (Originally Posted by hoppyinca)

okay, newby here, but why would you not assume the "worst case senario" when planning bailout to be at the end of the planned bottom time?

worst case in my mind would be break through or complete flood (and cocktail) at the end of bottom time. Really what ever it takes for your rig, or for you to consider your rig, no longer usable...

I agree with several view points on amount of gas to carry, where to carry it, and access to that gas (e.g. on board/ off board), but in my mind the starting point for bailout would be the "worst case" which is at max N2 loading... i.e. end of bottom time...

just my newbly 2 cents...
hoppyinca

Point of correction;
The worst case is not at the end of the BT because youll be back at the shot by then and doing an imediate ascent. The worst case is at the turn time to head back to the shot. Bail then and you have to have enough gas for a swim at depth (with highest associated consumption) back to security of upline (thats where all your dispersed buddies will be with their bail gas and maybe a deco platform with suface supply) You may even be inside a wreck and need to swim back to line at depth.

IMO the deep bail gas is the most critical. You need stacks of deep bottom gas on dives where an imediate ascent isnt the best option (strong currents, no chase boat, othe divers with gas around) Get back to the line you have stacks of time in the shallows to alert surface and get deco gas passed down. Bailing and free floating alone is much higher stress than being on a line where you have buddies around (above or below) and a boat at the end of the line.

Useful things ccr trimix courses*

(*good ones)

Gilles · 13th June 2007, 13:12

Quote: (Originally Posted by Drmike)

Ill chime in with my opinion/advice if you pay me what you should be paying for the CCR trimix course you should be doing

:P

Would a blob do?

wondersea · 13th June 2007, 13:15

Quote: (Originally Posted by Gilles)

Antoine;

I illustrate your version of a 100m bailout plan for all to see. I hope you don't mind.

I don't mind, we are here to discuss and progress in family

Quote: (Originally Posted by Gilles)

.

1) You have 5 different gases, all in strange volumes, probably needing 6 different tanks (or 1 large tank for your 3400L of 40/20 to make a total of 5 tanks for the other gases). Your creating logistics issues for yourself.

For this subject, I had not look at volume of gas very seriously, I have to get more gas if I plan to join the deco line with current, etc... But I have 5 tanks anyway (3 big on deco line + 2 small sidemount) + 2 Meg onboard. The Tank on deco line don't bother me, I can even have an other one ... But I want dive light.

That's right, logistics is for diving by myself with my boat, my friend. In France, I can't use the Meg in Dive center because not CE

Quote: (Originally Posted by Gilles)

2) What is the logic of using 8/62, other than being a convenient Heliair mix?

8/62 is an heliair and since we add oxy with the CCR what is the problem with this mix ? Easy to make and refill. I try to have NOT change of FN² when you change gas or the minimum ! And I have to join my basic deco line with some existing gas (18/44).

Quote: (Originally Posted by Gilles)

3) Why the switch from 8/62 to 12/57 for 1 stop? If your going to mix 12/57, why not use this as a bottom dil?

.

Well, I want dive light so 7L or 10L max sidemount that's all. First BO1 (8/62)is same as diluent so can be use as diluent or if bailout it will be the first breathing just time to take deco procédure look what I have to do and go to first stop. Anyway I can't breath it later so I use it to prepare deco. Then BO2 (12/57) give me time to deploy SMB or join deco line and start deco procedure. Anyway, with small tank like this I can't do more thing.

Just to be ready at the deco line and join correctly and smoothly the %mix of the first tank of the deco line.

Is that wrong strategy ?

wondersea · 13th June 2007, 13:26

Quote: (Originally Posted by Drmike)

Ill chime in with my opinion/advice if you pay me what you should be paying for the CCR trimix course you should be doing

but sorry cant supply a cert.
:P

Hi Mike,

Even with a course, it's not 4 or 5 training days which make you an experimented trimix diver for gas preparation.

I am talking strategy and tank/gas organization. There is not one strategy learn during course but many and compromize that each diver make.
I think I will ask some question about it for many YEAR again.

Hope you are going well ...

Take care

Drmike · 13th June 2007, 13:32

Quote: (Originally Posted by wondersea)

Hi Mike,

Even with a course, it's not 4 or 5 training days which make you an experimented trimix diver for gas preparation.

a good ccr trimix course should teach you how to optimally plan bailout - its not rocket science and there are 'rules' that make the selection/planning easy and make it optimum.
I agree there are ways to tweak it but the general basic rules remain and this is what I see missing here (such as even the basic 'worst case bail time' time is)

Quote:

Hope you are going well ...

Take care

I am thanks - hope you are too

Wasnt my intention to criticise you personally its good to be asking questions - just that I think there is a bad trend for ccr divers to start doing deeper mix dives without proper instruction (on bail out gas planning and optimisation)

wondersea · 13th June 2007, 14:01

Quote: (Originally Posted by Drmike)

just that I think there is a bad trend for ccr divers to start doing deeper mix dives without proper instruction (on bail out gas planning and optimisation)

I am sure agree with you, Mike, and it is not my purpose to tell diver go, it's simple you just have to get V planner and go dive.

My curiosity is because I saw almost 10 divers with different way (good and bad) to solve deco planification with CCR and by this thread I hope see trend or strong line to solve it better.

It permit also to tell on a forum what are good and what are non sense, if many use trimix, heliair, triox, heliox or what.

The goal is not to supply or demand a course but at this time who are doing what.

I hope this can help all beginners to make better his own organisation and show many good solutions.

Drmike · 13th June 2007, 14:08

Quote: (Originally Posted by wondersea)

My curiosity is because I saw almost 10 divers with different way (good and bad) to solve deco planification with CCR and by this thread I hope see trend or strong line to solve it better.
.

yeh I see the same variation amongst divers - usually amongst those who didnt get any instruction/do a course - maybe in part thats why

To be honest its rare I meet a ccr mix diver who has actually done a course.

Some of the ideas I hear are worrying

cheers
M

Mark Chase · 13th June 2007, 19:38

Quote: (Originally Posted by Drmike)

I think there is a bad trend for ccr divers to start doing deeper mix dives without proper instruction (on bail out gas planning and optimisation)

Pot meet Kettle

Even thow I sort of agree with you and respect the diving you did before going cave diving (He said franticly trying to avoid the tirade of verbal abuse

)

ATB

Mark Chase

Gilles · 13th June 2007, 23:59

I had hoped to get more than statements on how little we know. I/we knew that already.

Quote: (Originally Posted by Mark Chase)

Pot meet Kettle

(He said franticly trying to avoid the tirade of verbal abuse

)

ATB

Mark Chase

Let's give you some icon abuse, instead.

Quote: (Originally Posted by wondersea)

But I want dive light.

That's right, logistics is for diving by myself with my boat, my friend. In France, I can't use the Meg in Dive center because not CE

8/62 is an heliair and since we add oxy with the CCR what is the problem with this mix ? Easy to make and refill. I try to have NOT change of FN² when you change gas or the minimum ! And I have to join my basic deco line with some existing gas (18/44).

Well, I want dive light so 7L or 10L max sidemount that's all. First BO1 (8/62)is same as diluent so can be use as diluent or if bailout it will be the first breathing just time to take deco procédure look what I have to do and go to first stop. Anyway I can't breath it later so I use it to prepare deco. Then BO2 (12/57) give me time to deploy SMB or join deco line and start deco procedure. Anyway, with small tank like this I can't do more thing.

Just to be ready at the deco line and join correctly and smoothly the %mix of the first tank of the deco line.

Is that wrong strategy ?

Unless you are willing to go alpinist, there may be no other way to prepare adequate bailout for a 100m dive.

The stress from something going so wrong, requiring abandonment of your loop, will boost your RMV, and as Mike alluded to, the worst place will be at your turn around point.

A full ali80 tank will last 5 minutes at 100m with RMV 40L/m.

One may argue your 8/62 gas mix is unnecessarily hypoxic. Also when using this, your penalizing yourself with more deco obligation when you have bailed out to it.

Gas switching on bailout is needed and I have used Po2=1.5, and dPinert <= 0.5 ATA as criteria at switch point in the above example.

Then there are optimizations with team members.

There is an excellent thread titled "100m dive bailout" or similiar. Search and read. There is much to learn from it.

13th June 2007, 13:02	#41 (permalink)
Drmike Custom Title Allowed! Current Rebreather/s: MK 15.X Ouroboros Other CCR Home Build Other Rebreather/s: Inspiration Classic Other CCR Home Build Join Date: Feb 2005 Posts: 3,322	Re: Diluent / Bail-out / Deco Line gas choice Ill chime in with my opinion/advice if you pay me what you should be paying for the CCR trimix course you should be doing but sorry cant supply a cert. :P __________________ Cave diving is a sport Wreck diving is a sport Diving in general is a sport 'Rebreather diving' is not a sport its the delusional obsession with a highly dangerous and often inappropriate piece of equipment
(Offline)

13th June 2007, 13:11	#42 (permalink)
Drmike Custom Title Allowed! Current Rebreather/s: MK 15.X Ouroboros Other CCR Home Build Other Rebreather/s: Inspiration Classic Other CCR Home Build Join Date: Feb 2005 Posts: 3,322	Re: Diluent / Bail-out / Deco Line gas choice Quote: (Originally Posted by hoppyinca) okay, newby here, but why would you not assume the "worst case senario" when planning bailout to be at the end of the planned bottom time? worst case in my mind would be break through or complete flood (and cocktail) at the end of bottom time. Really what ever it takes for your rig, or for you to consider your rig, no longer usable... I agree with several view points on amount of gas to carry, where to carry it, and access to that gas (e.g. on board/ off board), but in my mind the starting point for bailout would be the "worst case" which is at max N2 loading... i.e. end of bottom time... just my newbly 2 cents... hoppyinca Point of correction; The worst case is not at the end of the BT because youll be back at the shot by then and doing an imediate ascent. The worst case is at the turn time to head back to the shot. Bail then and you have to have enough gas for a swim at depth (with highest associated consumption) back to security of upline (thats where all your dispersed buddies will be with their bail gas and maybe a deco platform with suface supply) You may even be inside a wreck and need to swim back to line at depth. IMO the deep bail gas is the most critical. You need stacks of deep bottom gas on dives where an imediate ascent isnt the best option (strong currents, no chase boat, othe divers with gas around) Get back to the line you have stacks of time in the shallows to alert surface and get deco gas passed down. Bailing and free floating alone is much higher stress than being on a line where you have buddies around (above or below) and a boat at the end of the line. Useful things ccr trimix courses* (*good ones) __________________ Cave diving is a sport Wreck diving is a sport Diving in general is a sport 'Rebreather diving' is not a sport its the delusional obsession with a highly dangerous and often inappropriate piece of equipment
(Offline)

13th June 2007, 13:12	#43 (permalink)
Gilles Worship the feminine Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Sep 2005 Location: Den Haag (Netherlands) Posts: 762	Re: Diluent / Bail-out / Deco Line gas choice Quote: (Originally Posted by Drmike) Ill chime in with my opinion/advice if you pay me what you should be paying for the CCR trimix course you should be doing :P Would a blob do? __________________ Gilles http://www.dirrebreather.com
(Offline)

13th June 2007, 13:15	#44 (permalink)
wondersea New Member Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Dec 2006 Location: France - Gerzat (63) - Sanary (83) Posts: 78	Re: Diluent / Bail-out / Deco Line gas choice Quote: (Originally Posted by Gilles) Antoine; I illustrate your version of a 100m bailout plan for all to see. I hope you don't mind. I don't mind, we are here to discuss and progress in family Quote: (Originally Posted by Gilles) . 1) You have 5 different gases, all in strange volumes, probably needing 6 different tanks (or 1 large tank for your 3400L of 40/20 to make a total of 5 tanks for the other gases). Your creating logistics issues for yourself. For this subject, I had not look at volume of gas very seriously, I have to get more gas if I plan to join the deco line with current, etc... But I have 5 tanks anyway (3 big on deco line + 2 small sidemount) + 2 Meg onboard. The Tank on deco line don't bother me, I can even have an other one ... But I want dive light. That's right, logistics is for diving by myself with my boat, my friend. In France, I can't use the Meg in Dive center because not CE Quote: (Originally Posted by Gilles) 2) What is the logic of using 8/62, other than being a convenient Heliair mix? 8/62 is an heliair and since we add oxy with the CCR what is the problem with this mix ? Easy to make and refill. I try to have NOT change of FN² when you change gas or the minimum ! And I have to join my basic deco line with some existing gas (18/44). Quote: (Originally Posted by Gilles) 3) Why the switch from 8/62 to 12/57 for 1 stop? If your going to mix 12/57, why not use this as a bottom dil? . Well, I want dive light so 7L or 10L max sidemount that's all. First BO1 (8/62)is same as diluent so can be use as diluent or if bailout it will be the first breathing just time to take deco procédure look what I have to do and go to first stop. Anyway I can't breath it later so I use it to prepare deco. Then BO2 (12/57) give me time to deploy SMB or join deco line and start deco procedure. Anyway, with small tank like this I can't do more thing. Just to be ready at the deco line and join correctly and smoothly the %mix of the first tank of the deco line. Is that wrong strategy ? __________________ Antoine Pannetier DirRebreather member www.DIRRebreather.com
(Offline)

13th June 2007, 13:26	#45 (permalink)
wondersea New Member Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Dec 2006 Location: France - Gerzat (63) - Sanary (83) Posts: 78	Re: Diluent / Bail-out / Deco Line gas choice Quote: (Originally Posted by Drmike) Ill chime in with my opinion/advice if you pay me what you should be paying for the CCR trimix course you should be doing but sorry cant supply a cert. :P Hi Mike, Even with a course, it's not 4 or 5 training days which make you an experimented trimix diver for gas preparation. I am talking strategy and tank/gas organization. There is not one strategy learn during course but many and compromize that each diver make. I think I will ask some question about it for many YEAR again. Hope you are going well ... Take care __________________ Antoine Pannetier DirRebreather member www.DIRRebreather.com
(Offline)

13th June 2007, 13:32	#46 (permalink)
Drmike Custom Title Allowed! Current Rebreather/s: MK 15.X Ouroboros Other CCR Home Build Other Rebreather/s: Inspiration Classic Other CCR Home Build Join Date: Feb 2005 Posts: 3,322	Re: Diluent / Bail-out / Deco Line gas choice Quote: (Originally Posted by wondersea) Hi Mike, Even with a course, it's not 4 or 5 training days which make you an experimented trimix diver for gas preparation. a good ccr trimix course should teach you how to optimally plan bailout - its not rocket science and there are 'rules' that make the selection/planning easy and make it optimum. I agree there are ways to tweak it but the general basic rules remain and this is what I see missing here (such as even the basic 'worst case bail time' time is) Quote: Hope you are going well ... Take care I am thanks - hope you are too Wasnt my intention to criticise you personally its good to be asking questions - just that I think there is a bad trend for ccr divers to start doing deeper mix dives without proper instruction (on bail out gas planning and optimisation) __________________ Cave diving is a sport Wreck diving is a sport Diving in general is a sport 'Rebreather diving' is not a sport its the delusional obsession with a highly dangerous and often inappropriate piece of equipment Last edited by Drmike : 13th June 2007 at 13:41.
(Offline)

13th June 2007, 14:01	#47 (permalink)
wondersea New Member Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Dec 2006 Location: France - Gerzat (63) - Sanary (83) Posts: 78	Re: Diluent / Bail-out / Deco Line gas choice Quote: (Originally Posted by Drmike) just that I think there is a bad trend for ccr divers to start doing deeper mix dives without proper instruction (on bail out gas planning and optimisation) I am sure agree with you, Mike, and it is not my purpose to tell diver go, it's simple you just have to get V planner and go dive. My curiosity is because I saw almost 10 divers with different way (good and bad) to solve deco planification with CCR and by this thread I hope see trend or strong line to solve it better. It permit also to tell on a forum what are good and what are non sense, if many use trimix, heliair, triox, heliox or what. The goal is not to supply or demand a course but at this time who are doing what. I hope this can help all beginners to make better his own organisation and show many good solutions. __________________ Antoine Pannetier DirRebreather member www.DIRRebreather.com
(Offline)

13th June 2007, 14:08	#48 (permalink)
Drmike Custom Title Allowed! Current Rebreather/s: MK 15.X Ouroboros Other CCR Home Build Other Rebreather/s: Inspiration Classic Other CCR Home Build Join Date: Feb 2005 Posts: 3,322	Re: Diluent / Bail-out / Deco Line gas choice Quote: (Originally Posted by wondersea) My curiosity is because I saw almost 10 divers with different way (good and bad) to solve deco planification with CCR and by this thread I hope see trend or strong line to solve it better. . yeh I see the same variation amongst divers - usually amongst those who didnt get any instruction/do a course - maybe in part thats why To be honest its rare I meet a ccr mix diver who has actually done a course. Some of the ideas I hear are worrying cheers M __________________ Cave diving is a sport Wreck diving is a sport Diving in general is a sport 'Rebreather diving' is not a sport its the delusional obsession with a highly dangerous and often inappropriate piece of equipment
(Offline)

13th June 2007, 19:38	#49 (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: 2,697	Re: Diluent / Bail-out / Deco Line gas choice Quote: (Originally Posted by Drmike) I think there is a bad trend for ccr divers to start doing deeper mix dives without proper instruction (on bail out gas planning and optimisation) Pot meet Kettle Even thow I sort of agree with you and respect the diving you did before going cave diving (He said franticly trying to avoid the tirade of verbal abuse ) ATB Mark Chase __________________ 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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13th June 2007, 23:59	#50 (permalink)
Gilles Worship the feminine Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Sep 2005 Location: Den Haag (Netherlands) Posts: 762	Re: Diluent / Bail-out / Deco Line gas choice I had hoped to get more than statements on how little we know. I/we knew that already. Quote: (Originally Posted by Mark Chase) Pot meet Kettle (He said franticly trying to avoid the tirade of verbal abuse ) ATB Mark Chase Let's give you some icon abuse, instead. Quote: (Originally Posted by wondersea) But I want dive light. That's right, logistics is for diving by myself with my boat, my friend. In France, I can't use the Meg in Dive center because not CE 8/62 is an heliair and since we add oxy with the CCR what is the problem with this mix ? Easy to make and refill. I try to have NOT change of FN² when you change gas or the minimum ! And I have to join my basic deco line with some existing gas (18/44). Well, I want dive light so 7L or 10L max sidemount that's all. First BO1 (8/62)is same as diluent so can be use as diluent or if bailout it will be the first breathing just time to take deco procédure look what I have to do and go to first stop. Anyway I can't breath it later so I use it to prepare deco. Then BO2 (12/57) give me time to deploy SMB or join deco line and start deco procedure. Anyway, with small tank like this I can't do more thing. Just to be ready at the deco line and join correctly and smoothly the %mix of the first tank of the deco line. Is that wrong strategy ? Unless you are willing to go alpinist, there may be no other way to prepare adequate bailout for a 100m dive. The stress from something going so wrong, requiring abandonment of your loop, will boost your RMV, and as Mike alluded to, the worst place will be at your turn around point. A full ali80 tank will last 5 minutes at 100m with RMV 40L/m. One may argue your 8/62 gas mix is unnecessarily hypoxic. Also when using this, your penalizing yourself with more deco obligation when you have bailed out to it. Gas switching on bailout is needed and I have used Po2=1.5, and dPinert <= 0.5 ATA as criteria at switch point in the above example. Then there are optimizations with team members. There is an excellent thread titled "100m dive bailout" or similiar. Search and read. There is much to learn from it. __________________ Gilles http://www.dirrebreather.com Last edited by Gilles : 14th June 2007 at 03:27.
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