+ Reply to Thread
Page 2 of 3 FirstFirst 1 2 3 LastLast
Results 11 to 20 of 24

Thread: bailout mode

  1. #11
    So many CCR So little etc Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase's Avatar
    Join Date
    Jan 2005
    Location
    Kent
    Posts
    5,205
    JJ Hybrid

    Inspo, Hammer Head, KISS rEvo

    Re: bailout mode

    The most important thing to look at on the fast bailout option is gas demand on the deep bailout gas. The whole point of a fast bailout is to get shallow and save deep gas.

    That said, Fast bailout doesn't make for nice deco.

    Using GF deco on rich helium mix I plan my dive on 10/90GF If I bail out ill do my deco on 10/90GF on OC unless i dont have enough gas.

    My fast bailout plan can be 50/125GF with a rock bottom plan of 100/XXXGF which basically involves ascending to 100GF for my first stop and ending deco by consuming all available gas before surfacing.


    The problem with VPM deco for bailout is it wont easily allow for you to blow off deep stops and reduce depth enhanced SAC in order to save deep gas.

    Ross could see the problem so came up with a system that reduced the deep stops as best he could within the confines of VPM.

    But for the system to offer clear benefit you need to go aggressive on the bailout. IE if your running +3 on "normal deco" then you need to be +1 or +0 on emergency bailout so see a significant saving.


    Planing a bailout on +0 or GF 100/100 is insane. I plan bailout on 10/90GF but i have a "drown or get out of the water (probably bent)" back up plan which is my last resort in the event of not having enough gas to do the normal deco.


    My emergency bailout plan comes into effect if I had to bail at the last min of the dive, I have lost my buddy, I cant make it to the deco station and the drop tank hasn't arrived.


    Thats a lot to go wrong before I need it, but I don't see the scenario as imposable and I wouldn't like to get to that point and not at least have some sort of plan.


    The problem i see with VPM is I cant mentally fudge an ascent plan so id need several sets of tables for several scenarios. With GF I need my 10/90 plan and a 100/XXX plan and i can fudge anything else in the middle.

    Before i jump in i need to know one figure only. What is the 100GF first stop depth ?

    Everything else i can make up my self on the fly based on available gas.


    ATB

    Mark

  2. #12
    RebreatherWorld Sponsor rossh is just really nice rossh is just really nice rossh is just really nice rossh is just really nice rossh is just really nice rossh is just really nice rossh is just really nice rossh is just really nice rossh is just really nice rossh is just really nice rossh's Avatar
    Join Date
    Jul 2005
    Location
    Canada
    Posts
    580

    Re: bailout mode

    Quote Originally Posted by wedivebc  View Original Post
    I accidentally cut off the gas in my first post but at Sunkmail's request I posted it later 83.4 vs 83.7 cuft is not much of a difference
    Yes the total of all the gas will likely be the same or worse, But if you look at the deep part, its has saved you about 1/3 the volume of your deep gas. Is that not where most bailout is limited?

    FBO is built with a 2 (or more) gas bailout strategy, and to get you up to the shallows, where you might have a bigger / longer lasting supply of OC available.

    As Mark says, if you want faster overall deco, then dial down the conservatism to speed things up along with FBO mode.

    Regards
    Last edited by rossh; 31st May 2010 at 10:39.
    Ross Hemingway
    ------------------------------------------

    V-Planner PC, Mac, Mobile, iPhone-iPod, Android. MultiDeco Android, PC, Mac.
    V-Planner Live and MultiDeco-X1 for the Liquivision X1 dive computer.
    MultiDeco-DR5 for the DR-5 dive computer.

  3. #13
    Dave Tomblin wedivebc has a reputation beyond repute wedivebc has a reputation beyond repute wedivebc has a reputation beyond repute wedivebc has a reputation beyond repute wedivebc has a reputation beyond repute wedivebc has a reputation beyond repute wedivebc has a reputation beyond repute wedivebc has a reputation beyond repute wedivebc has a reputation beyond repute wedivebc has a reputation beyond repute wedivebc has a reputation beyond repute wedivebc's Avatar
    Join Date
    Feb 2005
    Location
    Vancouver Island BC Canada
    Posts
    3,795
    Hollis Prism 2, Megalodon

    CCR Instructor Trainer

    Re: bailout mode

    Quote Originally Posted by rossh  View Original Post
    Yes the total of all the gas will likely be the same or worse, But if you look at the deep part, its has saved you about 1/3 the volume of your deep gas. Is that not where most bailout is limited?

    FBO is built with a 2 (or more) gas bailout strategy, and to get you up to the shallows, where you might have a bigger / longer lasting supply of OC available.

    As Mark says, if you want faster overall deco, then dial down the conservatism to speed things up along with FBO mode.

    Regards
    The problem I see here Ross is that I choose bailout gases for best deco (shortest) but also make adjustments for balanced deco volumes. That way I can carry the largest amount of BO gas in the least amount of tanks.
    I am trying to understand the purpose of saving deep bailout gas. It's not like I am going to be able use my deep bailout should I underestimate my shallow requirements. I am also reluctant to skip deep stops just for the purpose of saving gas that I actually already have. If there was a plan that got me out of the water faster for when things really go sideways (a drysuit flood for example) I would be all over it but increased risk in order to save bottom gas doesn't make sense, unless I am missing something here.
    Cheers,

    Dave....

    www.wedivebc.com

  4. #14
    RebreatherWorld Sponsor rossh is just really nice rossh is just really nice rossh is just really nice rossh is just really nice rossh is just really nice rossh is just really nice rossh is just really nice rossh is just really nice rossh is just really nice rossh is just really nice rossh's Avatar
    Join Date
    Jul 2005
    Location
    Canada
    Posts
    580

    Re: bailout mode

    Then if faster, but keeping the same model shape is the desired approach, I'd suggest to dial back the conservatism to 0, and select VPM-B. These can be selected in the bailout settings screen, so they wont interfere with normal dive plan settings..

    Regards
    Ross Hemingway
    ------------------------------------------

    V-Planner PC, Mac, Mobile, iPhone-iPod, Android. MultiDeco Android, PC, Mac.
    V-Planner Live and MultiDeco-X1 for the Liquivision X1 dive computer.
    MultiDeco-DR5 for the DR-5 dive computer.

  5. #15
    So many CCR So little etc Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase's Avatar
    Join Date
    Jan 2005
    Location
    Kent
    Posts
    5,205
    JJ Hybrid

    Inspo, Hammer Head, KISS rEvo

    Re: bailout mode

    Quote Originally Posted by wedivebc  View Original Post
    The problem I see here Ross is that I choose bailout gases for best deco (shortest) but also make adjustments for balanced deco volumes. That way I can carry the largest amount of BO gas in the least amount of tanks.
    I am trying to understand the purpose of saving deep bailout gas. It's not like I am going to be able use my deep bailout should I underestimate my shallow requirements. I am also reluctant to skip deep stops just for the purpose of saving gas that I actually already have. If there was a plan that got me out of the water faster for when things really go sideways (a drysuit flood for example) I would be all over it but increased risk in order to save bottom gas doesn't make sense, unless I am missing something here.



    IMHO The situation would be that your bailing out in a relaxed state so you follow normal deco, or your bailing out with massively increased SAC in which case you need to get shallow fast.

    If you blow off your deep stops and save 30% of your deep high helium mix you can sit out a gas switch on the high helium mix whilst you try to over come the panic or C02 induced elevated sac on a low viscosity gas.

    The second advantage of getting shallow fast is faster deco due to the pressure gradient.


    If you already plan your bailout on a 30SAC you may feel it unnecessary to have a emergency ascent plan? However with c02 there is always the possibility that your SAC could be 60lpm?

    Personally I use emergency ascent plans to find the limits of bailout. Ill plan for a relaxed bailout which has been the case up till now. When i have been forced to bail I have known well in advance and the act was no more exciting than a gas switch on an OC ascent. Then Ill plan a emergency bailout which will show the limit of bottom time assuming an elevated SAC emergency.

    These figures outline the gas plan.


    When i bought an X1 i tried to do this using VPM and found I couldn't achieve significant deep gas savings by dropping from level 4 to level 1


    I kicked off a thread to find out how other VPM users were coping with the issue but the feed back i got is that they weren't.

    Ross later brought out the bailout planning software which went a long way to solving the problem on the deep gas. As far as the shallow gas is concerned VPM is already less demanding than GF so I wasn't so sure that was an issue. A deco ascent of say 75mins will give me significant time deep whith which to expell any c02 or overcome any panic. Hopfully by the time I am on the shalow gas Ill be back to more normal SACs.



    ATB

    Mark

  6. #16
    Apprentice Meg Pilot kieranu is just really nice kieranu is just really nice kieranu is just really nice kieranu is just really nice kieranu is just really nice kieranu is just really nice kieranu is just really nice kieranu is just really nice kieranu is just really nice kieranu is just really nice kieranu's Avatar
    Join Date
    Sep 2005
    Location
    WA, Australia
    Posts
    708
    Megalodon APECS 2.7

    Re: bailout mode

    Quote Originally Posted by wedivebc  View Original Post
    Because it was just a test of the FBO mode and I wanted to make the comparison as simple as possible
    And besides why wouldn't you in practice? For the precise reason it keeps everything as simple as possible when the sh1t hits the fan.

    I would have thought FBO would generally be reserved for the worst case scenario where you have a full flood and diving in semi-closed mode to conserve bottom gas is no longer an option. At this point breathing may be elevated and you are more likely to blow your bottom gas on the deep stops.

    Slight tangent - are you diving the Pathfinder now? How is it compared to the full-blown Meg?
    Last edited by kieranu; 1st June 2010 at 08:36. Reason: punctuation

  7. #17
    Dave Tomblin wedivebc has a reputation beyond repute wedivebc has a reputation beyond repute wedivebc has a reputation beyond repute wedivebc has a reputation beyond repute wedivebc has a reputation beyond repute wedivebc has a reputation beyond repute wedivebc has a reputation beyond repute wedivebc has a reputation beyond repute wedivebc has a reputation beyond repute wedivebc has a reputation beyond repute wedivebc has a reputation beyond repute wedivebc's Avatar
    Join Date
    Feb 2005
    Location
    Vancouver Island BC Canada
    Posts
    3,795
    Hollis Prism 2, Megalodon

    CCR Instructor Trainer

    Re: bailout mode

    Quote Originally Posted by kieranu  View Original Post
    And besides why wouldn't you in practice? For the precise reason it keeps everything as simple as possible when the sh1t hits the fan.

    I would have thought FBO would generally be reserved for the worst case scenario where you have a full flood and diving in semi-closed mode to conserve bottom gas is no longer an option. At this point breathing may be elevated and you are more likely to blow your bottom gas on the deep stops.
    I don't use diluent for bailout. I have a deep bailout that is several points hotter than my diluent and the deco/bailout gas I choose gives me a bailout profile that is similar to the CCR deco curve. I also base gas choices on the volumes I will use in order to minimize the number of cylinders I will use. I find there is no greater complexity changing to a different gas so I don't see a benefit of using the same mix for bailout. I also carry enough bailout that I shouldn't need to use SCR mode (unless I screwed up my dive plan)


    Quote Originally Posted by kieranu  View Original Post
    Slight tangent - are you diving the Pathfinder now? How is it compared to the full-blown Meg?
    Oh and my Pathfinder is still sitting at ISC waiting to be dived.
    Cheers,

    Dave....

    www.wedivebc.com

  8. #18
    Dave Tomblin wedivebc has a reputation beyond repute wedivebc has a reputation beyond repute wedivebc has a reputation beyond repute wedivebc has a reputation beyond repute wedivebc has a reputation beyond repute wedivebc has a reputation beyond repute wedivebc has a reputation beyond repute wedivebc has a reputation beyond repute wedivebc has a reputation beyond repute wedivebc has a reputation beyond repute wedivebc has a reputation beyond repute wedivebc's Avatar
    Join Date
    Feb 2005
    Location
    Vancouver Island BC Canada
    Posts
    3,795
    Hollis Prism 2, Megalodon

    CCR Instructor Trainer

    Re: bailout mode

    Quote Originally Posted by Mark Chase  View Original Post
    Ross later brought out the bailout planning software which went a long way to solving the problem on the deep gas. As far as the shallow gas is concerned VPM is already less demanding than GF so I wasn't so sure that was an issue. A deco ascent of say 75mins will give me significant time deep whith which to expell any c02 or overcome any panic. Hopfully by the time I am on the shalow gas Ill be back to more normal SACs.



    ATB

    Mark
    I can see the advantage FBO mode would give you in v-planner live but cutting a separate profile for normal bailout and one for CO2 bailout does not seem practical. If am not in a position to need to conserve gas avoiding deep stops just seems like an unnecessary risk.
    Cheers,

    Dave....

    www.wedivebc.com

  9. #19
    So many CCR So little etc Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase's Avatar
    Join Date
    Jan 2005
    Location
    Kent
    Posts
    5,205
    JJ Hybrid

    Inspo, Hammer Head, KISS rEvo

    Re: bailout mode

    Quote Originally Posted by wedivebc  View Original Post
    I can see the advantage FBO mode would give you in v-planner live but cutting a separate profile for normal bailout and one for CO2 bailout does not seem practical. If am not in a position to need to conserve gas avoiding deep stops just seems like an unnecessary risk.

    I agree which is why I use GF deco for emergency planning.


    But if you prefer VPM then what other option do you have but to curt a load of tables for different possibilities?

    I can fudge GF on the fly no problem, but i haven't got a clue how to fudge VPM.

    FOr VPM to be viable for me id need a computer you can switch to OC then have a choice between say three levels of aggression on your ascent.

    Id also need a back up computer to confirm the primary is working :D

    ATB

    Mark

  10. #20

    Re: bailout mode

    Quote Originally Posted by Mark Chase  View Original Post
    FOr VPM to be viable for me id need a computer you can switch to OC then have a choice between say three levels of aggression on your ascent.
    I thought you can change conservatism on the fly now? No?

+ Reply to Thread
Page 2 of 3 FirstFirst 1 2 3 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts