VR£ Bailout gases - is it OK to leave them ON all the time?!!

Peter Piemonte · 12th May 2005, 11:30

I have followed this thread With interest, as I use a VR3 for CCR diving, and I was forced to "bail out" of a 55 meter rebreather dive last fall. The process of bailing out to OC, finding my way back to the upline, doing decompression stops in a current and in dark water and attempting to re index the VR3 to my new gasses in the dark was difficult. I was glad that I had OC bailout tables with me as that is what I ended up using.
I now always carry not only backup dive tables for the planned dive, but bailout tables as well. In some instances it would probably be possible to use the VR3 in this way but do not underestimate the stress a flooded unit and OC bailout can create. Worse if you have bailed out for another reason such as hypercapnia. Peter

Mark Chase · 12th May 2005, 15:25

Quote: (Originally Posted by Peter Piemonte)

I have followed this thread With interest, as I use a VR3 for CCR diving, and I was forced to "bail out" of a 55 meter rebreather dive last fall. The process of bailing out to OC, finding my way back to the upline, doing decompression stops in a current and in dark water and attempting to re index the VR3 to my new gasses in the dark was difficult. I was glad that I had OC bailout tables with me as that is what I ended up using.
I now always carry not only backup dive tables for the planned dive, but bailout tables as well. In some instances it would probably be possible to use the VR3 in this way but do not underestimate the stress a flooded unit and OC bailout can create. Worse if you have bailed out for another reason such as hypercapnia. Peter

This is a very good point. I have to admit I dont carry bailout tables but having said that I am fairly sure I could wing it just using the VR3 still in CCR mode

ATB

Mark Chase

Skeletor · 13th May 2005, 16:10

Just really thinking out loud, and not really thought this through, but . . . .

What would happen if you set your O/C gas to switch at the same PO2 as your CC setpoint by frigging the MOD of each gas ? (so for example 1.3 instead of 1.6)
From what I can see, the TTS calculation will still be slightly out, but possibly less so than the original question. Its also on the right side of being conservative , as you will be breathing a higher PO2 than the VR3 actually thinks at anything less than the switch depth, but you avoid breathing a lower PO2 than it predicts you should be. Still not ideal, but is this the lesser of two evils ?!! Personally, I would rather see a more conservative TTS displayed rather than sitting at a stop with no idea how long its going to take to clear.
The main thing I am unsure about is; will the VR£ start blarting at you if you then try to switch deeper than the MOD that you have told it for that gas in the event of an O/C bailout ? (I suppose you could just run with the VR£ deco and accept that its more conservative).

As I say, not fully thought through, so I am sure there is something I have missed

In any case, I'll stick to bailout tables without buttons

12th May 2005, 11:30	#31 (permalink)
Peter Piemonte KISS and rEvo diver Current Rebreather/s: Classic Kiss rEvo Other Rebreather/s: Classic Kiss rEvo Join Date: Apr 2005 Location: Massachusetts, USA Posts: 144	VR3 Bailout I have followed this thread With interest, as I use a VR3 for CCR diving, and I was forced to "bail out" of a 55 meter rebreather dive last fall. The process of bailing out to OC, finding my way back to the upline, doing decompression stops in a current and in dark water and attempting to re index the VR3 to my new gasses in the dark was difficult. I was glad that I had OC bailout tables with me as that is what I ended up using. I now always carry not only backup dive tables for the planned dive, but bailout tables as well. In some instances it would probably be possible to use the VR3 in this way but do not underestimate the stress a flooded unit and OC bailout can create. Worse if you have bailed out for another reason such as hypercapnia. Peter
(Online)

12th May 2005, 15:25	#32 (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	Quote: (Originally Posted by Peter Piemonte) I have followed this thread With interest, as I use a VR3 for CCR diving, and I was forced to "bail out" of a 55 meter rebreather dive last fall. The process of bailing out to OC, finding my way back to the upline, doing decompression stops in a current and in dark water and attempting to re index the VR3 to my new gasses in the dark was difficult. I was glad that I had OC bailout tables with me as that is what I ended up using. I now always carry not only backup dive tables for the planned dive, but bailout tables as well. In some instances it would probably be possible to use the VR3 in this way but do not underestimate the stress a flooded unit and OC bailout can create. Worse if you have bailed out for another reason such as hypercapnia. Peter This is a very good point. I have to admit I dont carry bailout tables but having said that I am fairly sure I could wing it just using the VR3 still in CCR mode 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 May 2005, 16:10	#33 (permalink)
Skeletor The 4th King Current Rebreather/s: Inspiration Vision Other Rebreather/s: Inspiration Classic Join Date: Feb 2005 Location: Purgatory Posts: 47	Just really thinking out loud, and not really thought this through, but . . . . What would happen if you set your O/C gas to switch at the same PO2 as your CC setpoint by frigging the MOD of each gas ? (so for example 1.3 instead of 1.6) From what I can see, the TTS calculation will still be slightly out, but possibly less so than the original question. Its also on the right side of being conservative , as you will be breathing a higher PO2 than the VR3 actually thinks at anything less than the switch depth, but you avoid breathing a lower PO2 than it predicts you should be. Still not ideal, but is this the lesser of two evils ?!! Personally, I would rather see a more conservative TTS displayed rather than sitting at a stop with no idea how long its going to take to clear. The main thing I am unsure about is; will the VR£ start blarting at you if you then try to switch deeper than the MOD that you have told it for that gas in the event of an O/C bailout ? (I suppose you could just run with the VR£ deco and accept that its more conservative). As I say, not fully thought through, so I am sure there is something I have missed In any case, I'll stick to bailout tables without buttons
(Offline)

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