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Thread: Diluent / Bail-out / Deco Line gas choice

  1. #41
    RBW Member Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike's Avatar
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    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

  2. #42
    RBW Member Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike's Avatar
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    Re: Diluent / Bail-out / Deco Line gas choice

    Quote Originally Posted by hoppyinca  View Original Post
    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)

  3. #43
    RBW Member Gilles is just really nice Gilles is just really nice Gilles is just really nice Gilles is just really nice Gilles is just really nice Gilles is just really nice Gilles is just really nice Gilles is just really nice Gilles is just really nice Gilles's Avatar
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    Re: Diluent / Bail-out / Deco Line gas choice

    Quote Originally Posted by Drmike  View Original Post
    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?

  4. #44
    RBW Member wondersea will become famous soon enough wondersea will become famous soon enough wondersea will become famous soon enough wondersea's Avatar
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    Re: Diluent / Bail-out / Deco Line gas choice

    Quote Originally Posted by Gilles  View Original Post
    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  View Original Post
    .

    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  View Original Post
    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  View Original Post
    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 ?

  5. #45
    RBW Member wondersea will become famous soon enough wondersea will become famous soon enough wondersea will become famous soon enough wondersea's Avatar
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    Re: Diluent / Bail-out / Deco Line gas choice

    Quote Originally Posted by Drmike  View Original Post
    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

  6. #46
    RBW Member Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike's Avatar
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    Re: Diluent / Bail-out / Deco Line gas choice

    Quote Originally Posted by wondersea  View Original Post
    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)
    Hope you are going well ...

    Take care
    I am thanks - hope you are too :D

    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)
    Last edited by Drmike; 13th June 2007 at 14:41.

  7. #47
    RBW Member wondersea will become famous soon enough wondersea will become famous soon enough wondersea will become famous soon enough wondersea's Avatar
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    Re: Diluent / Bail-out / Deco Line gas choice

    Quote Originally Posted by Drmike  View Original Post
    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.

  8. #48
    RBW Member Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike's Avatar
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    Re: Diluent / Bail-out / Deco Line gas choice

    Quote Originally Posted by wondersea  View Original Post

    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 :D

    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 :D
    cheers
    M

  9. #49
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    Re: Diluent / Bail-out / Deco Line gas choice

    Quote Originally Posted by Drmike  View Original Post
    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 :D


    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 :D)

    ATB

    Mark Chase

  10. #50
    RBW Member Gilles is just really nice Gilles is just really nice Gilles is just really nice Gilles is just really nice Gilles is just really nice Gilles is just really nice Gilles is just really nice Gilles is just really nice Gilles is just really nice Gilles's Avatar
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    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  View Original Post
    Pot meet Kettle :D


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

    ATB

    Mark Chase
    Let's give you some icon abuse, instead.



    :D

    Quote Originally Posted by wondersea  View Original Post

    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.
    Last edited by Gilles; 14th June 2007 at 04:27.

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