UHMS Deep Stops Workshop

bgpartri · 12th July 2008, 18:57

This discussion started in another thread, but it isn't a model-specific issue, so I'll answer here.

There were three research presentations about deep stops. Two indicated that they were worse for decompression, and one indicated that they might be useful in very specific no-deco dive profiles. Anecdotal data seems to favor deep stops.

I have believed in deep stops since Richard Pyle first discussed relieving fish's swim bladders. I was stunned to find out that there is little validation, and that the research done so far seems to invalidate deep stops for air dives at least.

The conclusion of the conference came close to saying there is no evidence of value, but concluded by saying that the evidence was conflicting because there is anecdotal evidence of value.

As you can imagine, with several computer manufacturers and model designers in the workshop, there was heated discussion. Since I am a technologist rather than a doctor or statistician, I will leave it to others to expand on the topic. There were several Rebreather World members there.

Quote: (Originally Posted by Lancer4545)

For those of us who weren't there. What was the outcome from the "Deep Stop" research and controversy??

Regards,

Lance

dave t · 12th July 2008, 19:13

well I am just a diver but I know if I dont do deep stops I feel like sh1t when I leave the water, if I do deep stops I feel fine.

When I say deep stops I am talking abouty GF generated profiles not pyle stops! My body doesnt like Pyle stops (sorry Rich!)

works for me!

Andy Del · 12th July 2008, 19:35

I found that doing 'deep stops', a-la VR3 left me feeling like crap. When it fell overboard, and I was diving using tables I felt fine - actually great. Others find diferently.

What seems to be known is that in the science of decompression modelling all is not known... It'll be interesting to read the outcomnes of this session.

01RMB · 13th July 2008, 00:25

On dives on a wreck in 75m (using 14/50 mix) when I follow the Pyle deep stops on the VR3 (0 conservatism) I have found (anedotically) that I will feel worse than if i miss the deep stops and continue to follow the vision set to GF 15/85 and the rest of the stops on the VR3.

Ignoring the VR3 deep stops - the VR3 (0 conservatism) and the Vision (GF 15/85) provide very similar profiles. I wish there was the option to set no deep stops on the VR3. Then I could miss the deep stops and avoid the whining from the VR3 when you miss the stop. It is no big problem but you do lose a little bit of information.

Lancer4545 · 13th July 2008, 03:36

Quote: (Originally Posted by 01RMB)

On dives on a wreck in 75m (using 14/50 mix) when I follow the Pyle deep stops on the VR3 (0 conservatism) I have found (anedotically) that I will feel worse than if i miss the deep stops and continue to follow the vision set to GF 15/85 and the rest of the stops on the VR3.

Ignoring the VR3 deep stops - the VR3 (0 conservatism) and the Vision (GF 15/85) provide very similar profiles. I wish there was the option to set no deep stops on the VR3. Then I could miss the deep stops and avoid the whining from the VR3 when you miss the stop. It is no big problem but you do lose a little bit of information.

Hey Rod,

I am assuming you are using a VR3 with Buh.......

How are the fingers........Got any finger prints back or are you off scott free

Regards,

Lance

Lancer4545 · 13th July 2008, 03:48

Quote: (Originally Posted by bgpartri)

This discussion started in another thread, but it isn't a model-specific issue, so I'll answer here.

There were three research presentations about deep stops. Two indicated that they were worse for decompression, and one indicated that they might be useful in very specific no-deco dive profiles. Anecdotal data seems to favor deep stops.

I have believed in deep stops since Richard Pyle first discussed relieving fish's swim bladders. I was stunned to find out that there is little validation, and that the research done so far seems to invalidate deep stops for air dives at least.

The conclusion of the conference came close to saying there is no evidence of value, but concluded by saying that the evidence was conflicting because there is anecdotal evidence of value.

As you can imagine, with several computer manufacturers and model designers in the workshop, there was heated discussion. Since I am a technologist rather than a doctor or statistician, I will leave it to others to expand on the topic. There were several Rebreather World members there.

Interesting theory........Makes VPM look as though it shouldn't work, seeing as the stops generally start much deeper than with Buh. But as we all know it does work for most divers most of the time and occasionally not for others.

Goes to show how little is really known about decompression theory and how we are all "Guinea Pigs" trying to work out what works for each and every one of us every time we dive deep.

Hopefully one day, and sooner rather than later, there are more studies done on decompression diving and with mixed gasses so we all have a better idea of what's going on and how to plan for safer diving. It was done for the commercial "Saturation" diving community....why not for the Tech Recreational Diver...........

Regards,

Lance

diverklondike · 13th July 2008, 06:24

Quote: (Originally Posted by dave t)

well I am just a diver but I know if I dont do deep stops I feel like sh1t when I leave the water, if I do deep stops I feel fine.

When I say deep stops I am talking abouty GF generated profiles not pyle stops! My body doesnt like Pyle stops (sorry Rich!)

works for me!

Ditto on the results of deep stops and add to that a slow ascent

01RMB · 13th July 2008, 11:46

Quote: (Originally Posted by Lancer4545)

Hey Rod,

I am assuming you are using a VR3 with Buh.......

How are the fingers........Got any finger prints back or are you off scott free

Regards,

Lance

Yes - the VR3 I use is Buhlmann. I am much happier using GF.

Fingers are getting better. The little finger is fine but the ring finger is still healing and will be a couple more weeks yet before I can get back in the water. Hence being restricted to internet diving.

dave-diving · 13th July 2008, 23:34

Bruce

The one thing interesting about the presentations on deep stops back at the DAN conference earlier this year was that much of the research work and data they presented was done on deep air and not on heliox or trimix.

I felt that the discussion did not attempt to do any favours for deep stops but the presenters were not showing data where helium off gassing/deep stops was shown to be of benefit. What works, works.

Dave C.

12th July 2008, 18:57	#1 (permalink)
bgpartri Rebreather Zealot Current Rebreather/s: Megalodon Other Rebreather/s: Inspiration Classic Sport Kiss Classic Kiss Titan Join Date: Apr 2005 Location: Vancouver, Canada Posts: 412	UHMS Deep Stops Workshop This discussion started in another thread, but it isn't a model-specific issue, so I'll answer here. There were three research presentations about deep stops. Two indicated that they were worse for decompression, and one indicated that they might be useful in very specific no-deco dive profiles. Anecdotal data seems to favor deep stops. I have believed in deep stops since Richard Pyle first discussed relieving fish's swim bladders. I was stunned to find out that there is little validation, and that the research done so far seems to invalidate deep stops for air dives at least. The conclusion of the conference came close to saying there is no evidence of value, but concluded by saying that the evidence was conflicting because there is anecdotal evidence of value. As you can imagine, with several computer manufacturers and model designers in the workshop, there was heated discussion. Since I am a technologist rather than a doctor or statistician, I will leave it to others to expand on the topic. There were several Rebreather World members there. Quote: (Originally Posted by Lancer4545) For those of us who weren't there. What was the outcome from the "Deep Stop" research and controversy?? Regards, Lance __________________ http://www.shearwaterresearch.com Good judgment comes from experience. Experience comes from bad judgment.
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12th July 2008, 19:13	#2 (permalink)
dave t Custom Title Allowed! Current Rebreather/s: Inspiration Classic Inspiration Vision Evolution Sport Kiss Classic Kiss Dolphin Ray Azimuth Home Build Other Rebreather/s: Dolphin Ray Azimuth Home Build Join Date: May 2005 Location: UK Posts: 654	Re: UHMS Deep Stops Workshop well I am just a diver but I know if I dont do deep stops I feel like sh1t when I leave the water, if I do deep stops I feel fine. When I say deep stops I am talking abouty GF generated profiles not pyle stops! My body doesnt like Pyle stops (sorry Rich!) works for me!
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12th July 2008, 19:35	#3 (permalink)
Andy Del Classic KISSer Current Rebreather/s: Sport Kiss Classic Kiss Other Rebreather/s: Join Date: Feb 2005 Location: Australia, Sunny Sydney Posts: 421	Re: UHMS Deep Stops Workshop I found that doing 'deep stops', a-la VR3 left me feeling like crap. When it fell overboard, and I was diving using tables I felt fine - actually great. Others find diferently. What seems to be known is that in the science of decompression modelling all is not known... It'll be interesting to read the outcomnes of this session. __________________ Yellow - the colour of greatness!
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13th July 2008, 00:25	#4 (permalink)
01RMB Evolving Current Rebreather/s: Evolution Other Rebreather/s: Join Date: May 2005 Location: Brisbane, Australia Posts: 192	Re: UHMS Deep Stops Workshop On dives on a wreck in 75m (using 14/50 mix) when I follow the Pyle deep stops on the VR3 (0 conservatism) I have found (anedotically) that I will feel worse than if i miss the deep stops and continue to follow the vision set to GF 15/85 and the rest of the stops on the VR3. Ignoring the VR3 deep stops - the VR3 (0 conservatism) and the Vision (GF 15/85) provide very similar profiles. I wish there was the option to set no deep stops on the VR3. Then I could miss the deep stops and avoid the whining from the VR3 when you miss the stop. It is no big problem but you do lose a little bit of information. __________________ Cheers Rod Last edited by 01RMB : 13th July 2008 at 00:36.
(Online)

13th July 2008, 03:36	#5 (permalink)
Lancer4545 Closed Circuit Divers Aus Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Jun 2007 Location: Cairns QLD Australia Posts: 659	Re: UHMS Deep Stops Workshop Quote: (Originally Posted by 01RMB) On dives on a wreck in 75m (using 14/50 mix) when I follow the Pyle deep stops on the VR3 (0 conservatism) I have found (anedotically) that I will feel worse than if i miss the deep stops and continue to follow the vision set to GF 15/85 and the rest of the stops on the VR3. Ignoring the VR3 deep stops - the VR3 (0 conservatism) and the Vision (GF 15/85) provide very similar profiles. I wish there was the option to set no deep stops on the VR3. Then I could miss the deep stops and avoid the whining from the VR3 when you miss the stop. It is no big problem but you do lose a little bit of information. Hey Rod, I am assuming you are using a VR3 with Buh....... How are the fingers........Got any finger prints back or are you off scott free Regards, Lance __________________ You can run but you can't hide! ISC Appointed Megalodon Dealer for East Australia http://www.closedcircuitdivers.com.au info@closedcircuitdivers.com.au
(Offline)

13th July 2008, 03:48	#6 (permalink)
Lancer4545 Closed Circuit Divers Aus Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Jun 2007 Location: Cairns QLD Australia Posts: 659	Re: UHMS Deep Stops Workshop Quote: (Originally Posted by bgpartri) This discussion started in another thread, but it isn't a model-specific issue, so I'll answer here. There were three research presentations about deep stops. Two indicated that they were worse for decompression, and one indicated that they might be useful in very specific no-deco dive profiles. Anecdotal data seems to favor deep stops. I have believed in deep stops since Richard Pyle first discussed relieving fish's swim bladders. I was stunned to find out that there is little validation, and that the research done so far seems to invalidate deep stops for air dives at least. The conclusion of the conference came close to saying there is no evidence of value, but concluded by saying that the evidence was conflicting because there is anecdotal evidence of value. As you can imagine, with several computer manufacturers and model designers in the workshop, there was heated discussion. Since I am a technologist rather than a doctor or statistician, I will leave it to others to expand on the topic. There were several Rebreather World members there. Interesting theory........Makes VPM look as though it shouldn't work, seeing as the stops generally start much deeper than with Buh. But as we all know it does work for most divers most of the time and occasionally not for others. Goes to show how little is really known about decompression theory and how we are all "Guinea Pigs" trying to work out what works for each and every one of us every time we dive deep. Hopefully one day, and sooner rather than later, there are more studies done on decompression diving and with mixed gasses so we all have a better idea of what's going on and how to plan for safer diving. It was done for the commercial "Saturation" diving community....why not for the Tech Recreational Diver........... Regards, Lance __________________ You can run but you can't hide! ISC Appointed Megalodon Dealer for East Australia http://www.closedcircuitdivers.com.au info@closedcircuitdivers.com.au
(Offline)

13th July 2008, 06:24	#7 (permalink)
diverklondike Just one of the Peasants Current Rebreather/s: Inspiration Classic Other CCR Other Rebreather/s: Inspiration Classic Other CCR Join Date: Oct 2005 Location: Delaware, USA Posts: 1,608	Re: UHMS Deep Stops Workshop Quote: (Originally Posted by dave t) well I am just a diver but I know if I dont do deep stops I feel like sh1t when I leave the water, if I do deep stops I feel fine. When I say deep stops I am talking abouty GF generated profiles not pyle stops! My body doesnt like Pyle stops (sorry Rich!) works for me! Ditto on the results of deep stops and add to that a slow ascent
(Online)

13th July 2008, 11:46	#8 (permalink)
01RMB Evolving Current Rebreather/s: Evolution Other Rebreather/s: Join Date: May 2005 Location: Brisbane, Australia Posts: 192	Re: UHMS Deep Stops Workshop Quote: (Originally Posted by Lancer4545) Hey Rod, I am assuming you are using a VR3 with Buh....... How are the fingers........Got any finger prints back or are you off scott free Regards, Lance Yes - the VR3 I use is Buhlmann. I am much happier using GF. Fingers are getting better. The little finger is fine but the ring finger is still healing and will be a couple more weeks yet before I can get back in the water. Hence being restricted to internet diving. __________________ Cheers Rod Last edited by 01RMB : 13th July 2008 at 20:55.
(Online)

13th July 2008, 23:34	#9 (permalink)
dave-diving Human Fuktup Engineering Current Rebreather/s: Megalodon Other CCR Dolphin Other Rebreather/s: Inspiration Classic Inspiration Vision Evolution Sport Kiss Classic Kiss MK 15.X Optima Other CCR Dolphin Join Date: May 2005 Location: Britain....Cornwall Posts: 22	Re: UHMS Deep Stops Workshop Bruce The one thing interesting about the presentations on deep stops back at the DAN conference earlier this year was that much of the research work and data they presented was done on deep air and not on heliox or trimix. I felt that the discussion did not attempt to do any favours for deep stops but the presenters were not showing data where helium off gassing/deep stops was shown to be of benefit. What works, works. Dave C. __________________ "Never argue with an idiot. They drag you down to their level, then beat you with experience."
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