147m on Pelagian

DrJM · 16th December 2007, 19:04

Thanks for sharing Mark, your explanation is appreciated, I'll think about it and maybe give it a try ...

Take care and keep taking us back some pict

Jerome

Inspired Trainer · 16th December 2007, 19:18

Quote: (Originally Posted by Mixaddict)

Mark, we have a recent example in Florida of a female cave diver who suffered an oxtox while at 1.45 PO2. If the high PO2 that you are using at depth has just a marginal improvement of overall deco obligation, why push the margins for limited results? Just curious?

Regards,
Randy

Hi Randy,

yes, ive heard of people toxing at low po2's too but there is often more to the story. Was this lady on OC or CCR? was the scrubber exhausted? was she working? did she have a predisposition to oxtox (some people do)? who confirmed it was oxtox and not something else? What kind of medication did/does she (actually) take? was there high WOB?

I would say it was incredibly rare to get toxed at 1.45 on a level playing field

Remember my example went from 1.5 to 1.3 to 1.2 over the deco phase...who is to say that 1.1 on the bottom increasing to 1.3/1.4 for deco is going to produce different but safer numbers? If workload reared its head i would let the setpoint decay...im using a manual CCR with needle closed on such relatively short deep dives trying to stay as relaxed as possible.

Cheers, Mark

Mixaddict · 16th December 2007, 19:29

Understood Mark. She was on OC. No known medication besides birth control pills. It is assumed that she had some type of predisposition to oxtox, since she had previously experienced (several months prior) a negative reaction while at 1.4. Her workload was moderate to light. I believe the evaluation of the coroner as well as her two dive buddies (one of which was her husband) lead to the conclusion that it was an oxtox event. Obviously, one can never be completely sure about these things, but it seems the most likely conclusion.

***Decodiver*** · 16th December 2007, 21:16

Quote: (Originally Posted by Mixaddict)

I believe the evaluation of the coroner as well as her two dive buddies (one of which was her husband) lead to the conclusion that it was an oxtox event. Obviously, one can never be completely sure about these things, but it seems the most likely conclusion.

Jesus, God Rest Her Soul.

This actually goes to show that at best we are guestimating in what we do.

My heart goes out to the people involved.

If anyone wants to read about real manned dives involving CCR and oxygen tolerance I suggest you get a copy of Oxygen and the Diver by Kenneth Donald, a very sobering read and unlike some of the USN tests actually involved prolonged manned dives.

Cheers,

Dave Cooper.

Inspired Trainer · 17th December 2007, 00:02

That is a shame. My condolences.

A friend of mine, who i dived regularly deep air to 2.8po2 with started to get cold so we switched to drysuits. On a 90m dive (2.0bar) she temporarily lost her vision and this was repeated on a subsequent 83m dive. Some weeks later she investigated being a chamber technician but failed the oxygen tolerance test by developing uncontrolled hiccuping and diaphragm spasm during the test.

The chamber manager recommended she not run po2's above 1.4 in the future because of this. I wonder how many people in the genpop are intolerent to high or prolonged medium po2's? There are indeed many ways to get caught out underwater.

Seasons Greetings

Mark

jhaaja · 17th December 2007, 05:42

Quote: (Originally Posted by Inspired Trainer)

That is a shame. My condolences.

A friend of mine, who i dived regularly deep air to 2.8po2 with started to get cold so we switched to drysuits. On a 90m dive (2.0bar) she temporarily lost her vision and this was repeated on a subsequent 83m dive. Some weeks later she investigated being a chamber technician but failed the oxygen tolerance test by developing uncontrolled hiccuping and diaphragm spasm during the test.

The chamber manager recommended she not run po2's above 1.4 in the future because of this. I wonder how many people in the genpop are intolerent to high or prolonged medium po2's? There are indeed many ways to get caught out underwater.

Seasons Greetings

Mark

Glad to hear that others have had the same symptoms

Those are not in the books I have read, hiccups and diaphragm spasm. I had those in water and also in the chamber. The chamber nurse did not like me taking the O2 mask of now and then during the chamber run. I just replied that I don+t want to convulse here and bang my head somewhere

JH

**Meerveld** · 23rd December 2007, 15:05

Quote: (Originally Posted by Inspired Trainer)

Just back from another HMS Victoria trip to Lebanon

We only had 4 days of good weather but got some good dives in. I used my Pelagian again down to 145m this time...conditions were pitch black with 12c on the bottom. Carl M from Samui (another Pelagian user) did his Trimix Explorer program in a 5mm wetsuit which was pretty hardcore! brrrrr

I am the Carl M described above and I can highly recommend Mark's Trimx Explorer program for helping take your game to the next level.

I did the Victoria dives OC as I have limited time on my Pelagian and did not fancy building hours at 140+ meters. However, I am looking forward to doing some more deep dives with Mark and my Pelagian. I will be rigging it the same way he does with 7,500 litres of DIL (2 x 15 litre tanks x 250 Bar).

One of advantages of the Pelagian is the ease of attaching any size of O2 and DIL tanks

Seasons greetings to all,

Carl

ianfirmin · 24th December 2007, 03:31

Quote: (Originally Posted by Meerveld)

I will be rigging it the same way he does with 7,500 litres of DIL (2 x 15 litre tanks x 250 Bar).

One of advantages of the Pelagian is the ease of attaching any size of O2 and DIL tanks

Very interesting thread, thanks for this. Can you tell us how the bail-out was configured?

Tia
Ian

ooops, just found the answer.

"He had the scrubber strapped onto the back of twin 15 litre steels pumped to 250 Bar. This gave him 7,500 litres of DIL/bailout bottom gas. This combined with two large stage tanks and a small O2 tank gave him full redundant OC bailout."

**Meerveld** · 24th December 2007, 04:51

Quote: (Originally Posted by ianfirmin)

Very interesting thread, thanks for this. Can you tell us how the bail-out was configured?

On the Pelagian the O2 and DIL tanks (usually two 3 litre tanks) are simply attached to the sides of the scrubber with standard tank bands. As the unit does not have the restrictions of an external cover any size of tanks can be attached.

However, very large tanks (steel 15's or 20's) would become hard to hold steady and there is no need for a 15 or 20 litre tank of O2. Mark's solution is to attach the scrubber to the top of a 15 litre twin set with a standard manifold with a 5-7 litre tank of O2 attached to the side of the twin set. The twin 15's are plumbed in as the DIL but have enough volume to provide a realistic OC bailout. Having said which, this is still insufficient for a 145 meter dive so Mark was carrying another two 11 litre stage tanks with richer mixes and had an 11 litre tank of O2 on the line at 6 meters.

As I was on OC I had twin 15's plus four 11 litre stage tanks. Although Mark's rig sounds large and cumbersome it was still less so than my OC rig. Mark also had the comfort of a full redundant bailout while I was seeing my OC resources with limited reserves dissipate with every breath.

Regards,

Carl

ianfirmin · 24th December 2007, 05:03

Thanks Carl,
A little while ago I took a close look at the Pelagian and found it a very well thought out piece of kit. The versatility of the tank mounting I thought an excellent idea.

Shame I won't be buying one.

Kind regards
Ian

16th December 2007, 19:04	#31 (permalink)
DrJM Deep Cave Explorer Current Rebreather/s: Ouroboros Other Rebreather/s: MK 15.X Join Date: May 2005 Location: France Posts: 336	Re: 147m on Pelagian Thanks for sharing Mark, your explanation is appreciated, I'll think about it and maybe give it a try ... Take care and keep taking us back some pict Jerome __________________ www.snoopyloop.com Deep Cave Exploration
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16th December 2007, 19:18	#32 (permalink)
Inspired Trainer New Member Current Rebreather/s: Pelagian Other Rebreather/s: Pelagian Join Date: Oct 2007 Location: London Posts: 63	Re: 147m on Pelagian Quote: (Originally Posted by Mixaddict) Mark, we have a recent example in Florida of a female cave diver who suffered an oxtox while at 1.45 PO2. If the high PO2 that you are using at depth has just a marginal improvement of overall deco obligation, why push the margins for limited results? Just curious? Regards, Randy Hi Randy, yes, ive heard of people toxing at low po2's too but there is often more to the story. Was this lady on OC or CCR? was the scrubber exhausted? was she working? did she have a predisposition to oxtox (some people do)? who confirmed it was oxtox and not something else? What kind of medication did/does she (actually) take? was there high WOB? I would say it was incredibly rare to get toxed at 1.45 on a level playing field Remember my example went from 1.5 to 1.3 to 1.2 over the deco phase...who is to say that 1.1 on the bottom increasing to 1.3/1.4 for deco is going to produce different but safer numbers? If workload reared its head i would let the setpoint decay...im using a manual CCR with needle closed on such relatively short deep dives trying to stay as relaxed as possible. Cheers, Mark
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16th December 2007, 19:29	#33 (permalink)
Mixaddict Always Learning! Current Rebreather/s: Inspiration Vision Evolution Other CCR Dolphin Other Rebreather/s: Inspiration Classic Other CCR Dolphin Join Date: Jan 2006 Location: Draper, Utah USA Posts: 426	Re: 147m on Pelagian Understood Mark. She was on OC. No known medication besides birth control pills. It is assumed that she had some type of predisposition to oxtox, since she had previously experienced (several months prior) a negative reaction while at 1.4. Her workload was moderate to light. I believe the evaluation of the coroner as well as her two dive buddies (one of which was her husband) lead to the conclusion that it was an oxtox event. Obviously, one can never be completely sure about these things, but it seems the most likely conclusion. __________________ Randy Thornton (MixAddict) Inspiration, Evolution,Hammerhead & Sentinel CCR Instructor
(Offline)

16th December 2007, 21:16	#34 (permalink)
*Decodiver* Administrator Current Rebreather/s: Megalodon Ouroboros rEvo Other CCR Other Rebreather/s: Inspiration Classic Inspiration Vision Evolution Sport Kiss Classic Kiss rEvo Other CCR Join Date: Jan 2005 Location: Geneva Posts: 2,168	Re: 147m on Pelagian Quote: (Originally Posted by Mixaddict) I believe the evaluation of the coroner as well as her two dive buddies (one of which was her husband) lead to the conclusion that it was an oxtox event. Obviously, one can never be completely sure about these things, but it seems the most likely conclusion. Jesus, God Rest Her Soul. This actually goes to show that at best we are guestimating in what we do. My heart goes out to the people involved. If anyone wants to read about real manned dives involving CCR and oxygen tolerance I suggest you get a copy of Oxygen and the Diver by Kenneth Donald, a very sobering read and unlike some of the USN tests actually involved prolonged manned dives. Cheers, Dave Cooper. __________________ CCR/OC Trimix Instructor Trainer CCR Training to Mixed Gas in Switzerland, France, UK & Germany on Megalodon/COPIS-Megalodon/KISS/Sport KISS/Ouroboros/rEvo/Inspiration/Evolution/Sentinel www.zerogravitydiving.com Rebreather World Terms & Conditions
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17th December 2007, 00:02	#35 (permalink)
Inspired Trainer New Member Current Rebreather/s: Pelagian Other Rebreather/s: Pelagian Join Date: Oct 2007 Location: London Posts: 63	Re: 147m on Pelagian That is a shame. My condolences. A friend of mine, who i dived regularly deep air to 2.8po2 with started to get cold so we switched to drysuits. On a 90m dive (2.0bar) she temporarily lost her vision and this was repeated on a subsequent 83m dive. Some weeks later she investigated being a chamber technician but failed the oxygen tolerance test by developing uncontrolled hiccuping and diaphragm spasm during the test. The chamber manager recommended she not run po2's above 1.4 in the future because of this. I wonder how many people in the genpop are intolerent to high or prolonged medium po2's? There are indeed many ways to get caught out underwater. Seasons Greetings Mark
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17th December 2007, 05:42	#36 (permalink)
jhaaja Custom Title Allowed! Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Mar 2005 Location: Finland Posts: 867	Re: 147m on Pelagian Quote: (Originally Posted by Inspired Trainer) That is a shame. My condolences. A friend of mine, who i dived regularly deep air to 2.8po2 with started to get cold so we switched to drysuits. On a 90m dive (2.0bar) she temporarily lost her vision and this was repeated on a subsequent 83m dive. Some weeks later she investigated being a chamber technician but failed the oxygen tolerance test by developing uncontrolled hiccuping and diaphragm spasm during the test. The chamber manager recommended she not run po2's above 1.4 in the future because of this. I wonder how many people in the genpop are intolerent to high or prolonged medium po2's? There are indeed many ways to get caught out underwater. Seasons Greetings Mark Glad to hear that others have had the same symptoms Those are not in the books I have read, hiccups and diaphragm spasm. I had those in water and also in the chamber. The chamber nurse did not like me taking the O2 mask of now and then during the chamber run. I just replied that I don+t want to convulse here and bang my head somewhere JH
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23rd December 2007, 15:05	#37 (permalink)
Meerveld Aviator, diver & sailor Current Rebreather/s: Pelagian Other Rebreather/s: Pelagian Join Date: Jul 2007 Location: Koh Samui, Thailand Posts: 30	Re: 147m on Pelagian Quote: (Originally Posted by Inspired Trainer) Just back from another HMS Victoria trip to Lebanon We only had 4 days of good weather but got some good dives in. I used my Pelagian again down to 145m this time...conditions were pitch black with 12c on the bottom. Carl M from Samui (another Pelagian user) did his Trimix Explorer program in a 5mm wetsuit which was pretty hardcore! brrrrr I am the Carl M described above and I can highly recommend Mark's Trimx Explorer program for helping take your game to the next level. I did the Victoria dives OC as I have limited time on my Pelagian and did not fancy building hours at 140+ meters. However, I am looking forward to doing some more deep dives with Mark and my Pelagian. I will be rigging it the same way he does with 7,500 litres of DIL (2 x 15 litre tanks x 250 Bar). One of advantages of the Pelagian is the ease of attaching any size of O2 and DIL tanks Seasons greetings to all, Carl __________________ We do not inherit the earth from our parents; we steal it from our children ~ based on a Native American proverb
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24th December 2007, 03:31	#38 (permalink)
ianfirmin New Member Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: Apr 2007 Location: Hexham, Northumberland Posts: 37	Re: 147m on Pelagian Quote: (Originally Posted by Meerveld) I will be rigging it the same way he does with 7,500 litres of DIL (2 x 15 litre tanks x 250 Bar). One of advantages of the Pelagian is the ease of attaching any size of O2 and DIL tanks Very interesting thread, thanks for this. Can you tell us how the bail-out was configured? Tia Ian ooops, just found the answer. "He had the scrubber strapped onto the back of twin 15 litre steels pumped to 250 Bar. This gave him 7,500 litres of DIL/bailout bottom gas. This combined with two large stage tanks and a small O2 tank gave him full redundant OC bailout." Last edited by ianfirmin : 24th December 2007 at 04:52. Reason: Answered my own question....
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24th December 2007, 05:03	#40 (permalink)
ianfirmin New Member Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: Apr 2007 Location: Hexham, Northumberland Posts: 37	Re: 147m on Pelagian Thanks Carl, A little while ago I took a close look at the Pelagian and found it a very well thought out piece of kit. The versatility of the tank mounting I thought an excellent idea. Shame I won't be buying one. Kind regards Ian
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