calculating Bailout using V-Planner

Hanssing · 19th July 2007, 19:21

Quote: (Originally Posted by Ned Kelly)

Hi
Could someone tell me how to use V-planner to run a bailout profile from the bottom. Which ever way I do it it doesn't bailout until shallower.

As others have written, the ascending part starts with the gas-switch at depth.
This not the case when deco'ing, ie. stop-lines in the plan, here deco-gas switch are done when stop-depth is reached.
Thats a bit counterintuitive at first but makse sense, if you read the lines as something you 'do', ie. ascend on a certain gas, or hang on a certain gas.

Beware of worstcase-scenarious:
If you have to reach a shot-line. Its actually not at the end of bottom-time but halfway through it, as you have to swim back on OC at depth....
In V-planner this is done by inserting an OC-segment at depth of half the panned bottomtime, and reducing the planned CCR-bottomtime accordingly. It really uses gas in the plan, and then you dont need the bottom-bailout-gas in the deco-list as v-planner will continue to use the OC-gas until switch-depth of ex. EAN80.

Regards
Nicolai

rossh · 20th July 2007, 02:34

Quote: (Originally Posted by colinicky)

So Ross just to clarify :- If I enter a dil of 18/45 for the ccr segment I must enter the same mix as a bailout if I want to bail out from the bottom ?
If not then I am wondering how to bailout from the bottom on a different mix to my dil ?
TIA

To use the current diluent as an OC bail, enter that mix into OC deco column as well.
To make any other OC bail mix, enter it in the OC deco column. It will be selected into use based on the 1.4 to 1.6 O2% settings in config.
To use a OC bail mix deeper than the regular 1.4 - 1.6 pp, set a manual depth override when entering that mix into the OC deco column.

Allan_o · 20th July 2007, 04:52

Quote: (Originally Posted by Hanssing)

Beware of worstcase-scenarious:
If you have to reach a shot-line. Its actually not at the end of bottom-time but halfway through it, as you have to swim back on OC at depth....
In V-planner this is done by inserting an OC-segment at depth of half the panned bottomtime, and reducing the planned CCR-bottomtime accordingly. It really uses gas in the plan, and then you dont need the bottom-bailout-gas in the deco-list as v-planner will continue to use the OC-gas until switch-depth of ex. EAN80.

Regards
Nicolai

Hi Nicolai.
You are right about the oc segment, i forgot that one and was writing from a deco point of view

regards Allan

womble · 23rd July 2007, 22:13

what stephanie / others said is right. It will assume bailout at depth so 56-36m is OC.

Also dont forget to put in realistic RMV's !!

Stephane · 23rd July 2007, 22:19

Quote: (Originally Posted by womble)

what stephanie / others said is right. It will assume bailout at depth so 56-36m is OC.

Also dont forget to put in realistic RMV's !!

Who ??? Let me touch ... not me!

GuyW · 24th July 2007, 10:39

Just an observation, but VPM is probably not the best solution for bailout. You use heaps of gas with all those deep stops, gas than you can ill aford.

Use VPM for your dive plan by all means, but you may want to consider a minimum deep stop plan to get shallow ASAP if you have to bail out.

Guy

Allan_o · 24th July 2007, 13:36

Hi Guy.

What would you recommend instead of vpm ?

Z-Planner tends to get you rather quickly out of the water but it seems at bit quick to me.

But you are right about an enourmos ammount of gas used for the deep stops...

regards
Allan

womble · 24th July 2007, 18:52

Quote: (Originally Posted by Stephane)

Who ??? Let me touch ... not me!

OOOps! . . . . . Sorry!!

johnnied · 25th July 2007, 23:49

Quote: (Originally Posted by Allan_o)

Hi Guy.

What would you recommend instead of vpm ?

Z-Planner tends to get you rather quickly out of the water but it seems at bit quick to me.

But you are right about an enourmos ammount of gas used for the deep stops...

regards
Allan

So what's the verdict on alternative programs for bailout planning?

GuyW · 26th July 2007, 11:53

An alternative would be a Buhlmann or GF based schedule, or at least re-run V-Planner with minimum conservatism, and extend the deep stops . I.E. an bend-em-and-mend-em profile. Maybe VPM-E with zero conservatism ?

I'm not bagging VPM by the way, but it is just an observation that the deep stops consume a lot of gas. And if you are bailed out an "elegant" deco is probably secondary to having enough gas to get the the air above.

E.G. I use a VR3 and if I was bailing out would probably blow off the deep stops to get shallow quickly, then pad out the standard Buhlmann stops when I am settled in to deco and understand my gas requirements better.

People tend to under estimate bailout gas requirements so an excessively deep bailout plan just exacerbates the problem. E.G. if you have a CO2 problem you could be breathing your bailout at 50l/min.

Guy

19th July 2007, 19:21	#11 (permalink)
Hanssing flap-flop ..... flap-flop Current Rebreather/s: rEvo Other Rebreather/s: rEvo Join Date: Nov 2005 Location: Denmark Posts: 407	Re: calculating Bailout using V-Planner Quote: (Originally Posted by Ned Kelly) Hi Could someone tell me how to use V-planner to run a bailout profile from the bottom. Which ever way I do it it doesn't bailout until shallower. As others have written, the ascending part starts with the gas-switch at depth. This not the case when deco'ing, ie. stop-lines in the plan, here deco-gas switch are done when stop-depth is reached. Thats a bit counterintuitive at first but makse sense, if you read the lines as something you 'do', ie. ascend on a certain gas, or hang on a certain gas. Beware of worstcase-scenarious: If you have to reach a shot-line. Its actually not at the end of bottom-time but halfway through it, as you have to swim back on OC at depth.... In V-planner this is done by inserting an OC-segment at depth of half the panned bottomtime, and reducing the planned CCR-bottomtime accordingly. It really uses gas in the plan, and then you dont need the bottom-bailout-gas in the deco-list as v-planner will continue to use the OC-gas until switch-depth of ex. EAN80. Regards Nicolai __________________ Woohooo - I can change my rEvo! Its going to be bitchin' tricked out piece of gear
(Online)

20th July 2007, 02:34	#12 (permalink)
rossh Custom Title Allowed! Current Rebreather/s: Not Bought Yet Other Rebreather/s: Not Bought Yet Join Date: Jul 2005 Location: Canada Posts: 111	Re: calculating Bailout using V-Planner Quote: (Originally Posted by colinicky) So Ross just to clarify :- If I enter a dil of 18/45 for the ccr segment I must enter the same mix as a bailout if I want to bail out from the bottom ? If not then I am wondering how to bailout from the bottom on a different mix to my dil ? TIA To use the current diluent as an OC bail, enter that mix into OC deco column as well. To make any other OC bail mix, enter it in the OC deco column. It will be selected into use based on the 1.4 to 1.6 O2% settings in config. To use a OC bail mix deeper than the regular 1.4 - 1.6 pp, set a manual depth override when entering that mix into the OC deco column. __________________ Regards, Ross Hemingway V-Planner Live for the X1 V-Planner VPM-B Nitrox Trimix CCR Deco planning for Technical Divers www.v-planner.com
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20th July 2007, 04:52	#13 (permalink)
Allan_o New Member Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Dec 2005 Location: Copenhagen Denmark Posts: 81	Re: calculating Bailout using V-Planner Quote: (Originally Posted by Hanssing) Beware of worstcase-scenarious: If you have to reach a shot-line. Its actually not at the end of bottom-time but halfway through it, as you have to swim back on OC at depth.... In V-planner this is done by inserting an OC-segment at depth of half the panned bottomtime, and reducing the planned CCR-bottomtime accordingly. It really uses gas in the plan, and then you dont need the bottom-bailout-gas in the deco-list as v-planner will continue to use the OC-gas until switch-depth of ex. EAN80. Regards Nicolai Hi Nicolai. You are right about the oc segment, i forgot that one and was writing from a deco point of view regards Allan
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23rd July 2007, 22:13	#14 (permalink)
womble Custom Title Allowed! Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Aug 2006 Location: UK Posts: 196	Re: calculating Bailout using V-Planner what stephanie / others said is right. It will assume bailout at depth so 56-36m is OC. Also dont forget to put in realistic RMV's !! __________________ "What could possibly go wrong?? . . "
(Online)

23rd July 2007, 22:19	#15 (permalink)
Stephane Stéphane Acounis Current Rebreather/s: rEvo Other Rebreather/s: rEvo Join Date: Nov 2005 Location: Nantes - France Posts: 773	Re: calculating Bailout using V-Planner Quote: (Originally Posted by womble) what stephanie / others said is right. It will assume bailout at depth so 56-36m is OC. Also dont forget to put in realistic RMV's !! Who ??? Let me touch ... not me! __________________ Stéphane
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24th July 2007, 10:39	#16 (permalink)
GuyW Old Member Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Apr 2006 Location: Sydney, Australia Posts: 61	Re: calculating Bailout using V-Planner Just an observation, but VPM is probably not the best solution for bailout. You use heaps of gas with all those deep stops, gas than you can ill aford. Use VPM for your dive plan by all means, but you may want to consider a minimum deep stop plan to get shallow ASAP if you have to bail out. Guy
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24th July 2007, 13:36	#17 (permalink)
Allan_o New Member Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Dec 2005 Location: Copenhagen Denmark Posts: 81	Re: calculating Bailout using V-Planner Hi Guy. What would you recommend instead of vpm ? Z-Planner tends to get you rather quickly out of the water but it seems at bit quick to me. But you are right about an enourmos ammount of gas used for the deep stops... regards Allan
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24th July 2007, 18:52	#18 (permalink)
womble Custom Title Allowed! Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Aug 2006 Location: UK Posts: 196	Re: calculating Bailout using V-Planner Quote: (Originally Posted by Stephane) Who ??? Let me touch ... not me! OOOps! . . . . . Sorry!! __________________ "What could possibly go wrong?? . . "
(Online)

25th July 2007, 23:49	#19 (permalink)
johnnied New Member Current Rebreather/s: Inspiration Vision Other Rebreather/s: Inspiration Vision Join Date: Oct 2006 Location: London Posts: 48	Re: calculating Bailout using V-Planner Quote: (Originally Posted by Allan_o) Hi Guy. What would you recommend instead of vpm ? Z-Planner tends to get you rather quickly out of the water but it seems at bit quick to me. But you are right about an enourmos ammount of gas used for the deep stops... regards Allan So what's the verdict on alternative programs for bailout planning?
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26th July 2007, 11:53	#20 (permalink)
GuyW Old Member Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Apr 2006 Location: Sydney, Australia Posts: 61	Re: calculating Bailout using V-Planner An alternative would be a Buhlmann or GF based schedule, or at least re-run V-Planner with minimum conservatism, and extend the deep stops . I.E. an bend-em-and-mend-em profile. Maybe VPM-E with zero conservatism ? I'm not bagging VPM by the way, but it is just an observation that the deep stops consume a lot of gas. And if you are bailed out an "elegant" deco is probably secondary to having enough gas to get the the air above. E.G. I use a VR3 and if I was bailing out would probably blow off the deep stops to get shallow quickly, then pad out the standard Buhlmann stops when I am settled in to deco and understand my gas requirements better. People tend to under estimate bailout gas requirements so an excessively deep bailout plan just exacerbates the problem. E.G. if you have a CO2 problem you could be breathing your bailout at 50l/min. Guy
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