Way of the deep end: Seb (Subs) Murat aims for No-Limits Record

[cdavis]

I can't see how his new stuff could be useful to normal divers, but when I first read his FRC stuff, I couldn't see it either; it just sounded nuts. Now I dive FRC all the time, so you never know. . . .

Thank you Seb! Best of luck!

 

[efattah]

The idea is to selectively cool the brain only, not the rest of the body.

Seb did give me a vague description of how it is done but it is not for me to disclose.

 

[sebastien murat]

- Actually, the idea is to cool the whole body not just the brain. The brain has a very high metabolic rate so any reductions in its O2 consumption rate is beneficial, especially considering that during diving it increases its share of cardiac output. But, other organs like the heart also stand to get a great benefit.

- Importantly, it should be recognized that what I'm talking about is not therapeutic hypothermia (TH). There's a big difference between TH, which is pathological (i.e., not homeostatically controlled) and which seeks to overwhelm the body's natural counter-thermoregulatory defenses, versus hibernation (torpor, really) which is homeostatically controlled, and highly coordinated/orchestrated. Metabolic rate depression in torpor is both is both temperature dependent and independent which means you can get to about 75% of basal metabolic rate, versus on 25% of BMR with TH. In torpor there is permissive whole-body cooling up to some critical threshold, since the thermostat is down-regulated. Moreover, thermal windows on the body open-up to dump excess heat in torpor. This is not the case during TH. Upon reaching the lower critical temperature in torpor shivering kicks in to prevent over-cooling. In TH cooling is no longer regulated by the body, shivering will never kick-in to protect itself; the body is purely at the mercy of the medics, and its easy to over-shoot the therapeutic target temperature, resulting in arrythmias, etc.


- MRS : magnetic resonance spectroscopy .... think MRI chamber

- By the way there's no ice-cream headache, you don't become unconscious, and its a universal mechanism, which is a new component of the dive response, akin to that already shown in diving birds and mammals.

Best
S

 

[watts]

Trying to get my head around this. You will use artificial means to cool your body/brain then frc dive to 700 foot? Will not water temp reheat everything or is there a window open? Without artificial cooling using only water temp wouldnt warm water dives not be ideal for this approach? And how do you not shiver? :waterwork
More questions coming. My head hurts and its not even cold.

 

[watts]

Just looked up Torpor on google. Realy interesting what induces it ie fasting, food, temp and chemicals. This is great stuff.

 

[sebastien murat]

There's a lot of research effort looking into what the trigger(s) might be for inducing such altered and depressed metabolic states on-demand. The actual trigger has not been found although its been suspected to involve fasting, cold exposure, etc. All the approached involves dissecting things by looking at piece-by-piece biochemical pathways. I used an integrated approach to trigger it in a clinical setting.

S

 

[DivingDane]

Best of luck with the dives, Seb.

looking forward to following this closely.

i would imagin that once the brain is cooled to a point, like you say 34C then the water temperature would still be lower than this so you would have some time before it would reheat, mind you i'm assuming there is also a self control element to this which allows you to maintain low brain function to reduce the speed at which the brain rehets to standard temperature, i wouldnt imagine water temp would be much of an issue provided it remains lower than the target temperature.

hopefully get the chance to catch up with you now that your back.

good luck seb.

DD

 

[joshmeyer]

still i wonder about the technique used for equalization, but if i read
correctly, sebastien won't tell anything specific concerning this fact
before the actual dive takes place.

wet equalization doesn't seem to be very practically, or at least it seems so
as i've never heard or read from anybody who applied it successfully.

 

[Simos]

still i wonder about the technique used for equalization, but if i read
correctly, sebastien won't tell anything specific concerning this fact
before the actual dive takes place.

wet equalization doesn't seem to be very practically, or at least it seems so
as i've never heard or read from anybody who applied it successfully.

I don't think equalisation is the 'secret' here that cannot be revealed - if no external methods (eg EQEX) are used and total alveolar collapse is expected around 30-40m then wet equalisation is the only (known - to me perhaps lol) way to get down to 700ft unless Seb has massive cheeks

In any case the way I understand it is that Seb will try this new method to induce 'hibernation' and then he's going to start dropping like a stone until he feels that it's time to starting coming up, then get to the surface and check what depth he's done as opposed to aim for 700ft specifically.

But if he feels 700ft should be doable, then the equalisation method used should reflect that.

There are already rare cases reported as far as I remember of people who drowned and sunk to the bottom of very cold rivers etc, only to be recovered after hours and revived with no brain damage etc so should be possible for sure to get to such a low metabolic rate.

Will be following the thread with great interest - best of luck Seb.

 

[efattah]

Wet equalization is relatively easy, many people have done it before (Mandy, Martin, Pipin, Patrick Musimu, Audrey) all on record attempts.

It is much less painful if the water salinity is right, or if you pre-fill your eustachian tubes with isotonic water like Mayol used to do.

Herbert and I tried it, but we both prefer air equalization if it is still possible. In my case I was experimenting with wet equalizing because I could not equalize beyond 100m on an FRC dive, but with packing air equalizing is near limitless.

So I would say that equalizing is not the main challenge of Seb's dive.

 

[yugyug]

Good luck Seb! Very interested to see the results of your endeavours.

 

[Siku]

There's a lot of research effort looking into what the trigger(s) might be for inducing such altered and depressed metabolic states on-demand. The actual trigger has not been found although its been suspected to involve fasting, cold exposure, etc.
S

Sounds like Winter, which ties in with the hibernating bears. I've read accounts of early settlers in the high arctic that theorise they would have had to basically hibernate (unlike current indigenous populations which have relatively higher technological and cultural adaptation to arctic environments).

I wonder if sunlight plays a role too?

The hardest part to me sounds like 'complete aveolal collapse'.. How is that even possible?! Awe inspiring thought, though, if this represents a sort of freediving 'event horizon'.

The squeeze, combined with wet equalisation sounds absolutely terrifiying - but then I get claustrophobic just diving to the the bottom of the 3m pool after heavy reverse packing! Lol!

Truly amazing project, good luck Sebastien. And nice to see a 'low-tech' contender to Herbert's crown!

 

[kevtron]

This is amazing. I saw the video linked from a FB group, and had a lot of questions which all got answered here. Now I'm much more excited to see what you can do! And it's great how the sport keeps evolving and we keep learning more and more about what our bodies are capable of.

Dive safe!

 

[onemanarmyxx7]

This is quite funny, I've started deep diving in summer, but couple of months before (on a scuba diving trip) I read an article about sperm whale diving technique. At the time I wish I could do it same way, but undestand that I evolved slightly diffrent way .
Passed all my training courses and realised that my biggest problem the stage after contractions, when my limbs get heavy, so I started training FRC quite a lot, but I still sh*t myself when I get to that stage. My DR takes ages to start, so THIS could be a great help.

Any chance to enroll on a course..? Possibly in Europe.. I found out that there was one in Finland some time ago.

Thanks for sharing the info Sebastian, good luck..!!



btw, this is the video that brought Seb's E-diving to my attention
[ame=http://www.youtube.com/watch?v=sY5G8Ei-VDQ&feature=player_embedded]Sebastien (Subs) Murat Freediving Evolution.mpg - YouTube[/ame]

this is something I watch some time ago, that got me thinking about FRC..
[ame=http://www.youtube.com/watch?v=xBQVJVT4Zec]Mark Visser Big Wave Surfer 2:20m -ve Breath Hold Swim 50m - YouTube[/ame]

 

[cebaztian]

Maybe places like Nordic Deep in Sweden behold new untapped possibilities?

Nothing untapped.
After Murat visited us before Nordic Deep 2005/6(?), I moved my PB in CNF from 46 to 51 meters and to a national record, by basically removing my suit. The chill at depth was painful (it hurt), and since I did not breathe up CO2 gave me nightmares and I thought I would BO at 30, but as I approached the surface, my mind cleared, and I have never before or since made a dive that ended in such clarity of mind (as opposed to the body/muscles that felt like they where cast in iron and screaming in anxiety). Dive response diving at its best.

SebastiAn

 

[sebastien murat]

Way back when: a short anecdote

I first started diving on empty in the very late 90s whilst working as a dive instructor on Australia's GBR. I didn't stumble on this technique by accident, rather it was , let's say an `evolutionary pressure´. Basically, I was getting sick and tired of hauling up lead with every dive. Finding myself well away from the dive boat I had the option of either continuing to dive as is or ditch my employers w/belt. So, I ditched the w/belt. The penny dropped when I realized I could trade off fighting buoyancy most of the way if I surrendered some air. Being a rather curious person by nature, it quickly became evident that there was essentially no difference in my performance, except that I was much more crisp and lucid upon surfacing. Equalizing was of course going to be the weak link; I spent the next year stuck in 20 or so meters of water learning how to equalize. I pondered very little about the consequences of this novel strategy until a fellow dive instructor who saw what I was doing thought it curious that I was diving this way since he'd seen a documentary about some whales which were diving like that. From that point on I spent my free time pouring over the literature, some of which went back to the 1800s. I first discussed the technique publicly on a divers forum in early 2000 something .... I think it was called apnea groups or something like that ... maybe it still exists. There I met people like Eric and Rudi, and the rest is history.

Seb

 

[efattah]

Way back when: the story continues.

Independently from Seb, in 2001 I wrote a long document called 'In Search of the Ideal Freediving Physiology.' In this document I focused on retention of consciousness as the prime factor in diving, and I calculated that the ideal lung volume was not necessarily the maximum volume. This was easy to show, for example someone with a 100L lung volume would need so much weight to break the surface that they could never get off the bottom. So I was startled by the conclusion or possibility that taking as much air as possible before starting the dive was not obviously the best solution. I shared this idea with many top divers and received nothing but ridicule. I then sent this document to Seb in 2001 and he told me he had already been experimenting with this technique for some time, and the rest is history...

 

[sebastien murat]

I have a vague notion that you may be right Eric ... its seems so long ago and so much has happened. I might even recall that Rudi may have been priming his divers this way in order to better tolerate depth. Either way, I wonder how many people in history may have played around with this strategy. Certainly, it doesn't take too much of a stretch of the imagination to see how one might employ such a strategy to avoid struggling against +ve buoyancy in a mere few meters of water picking shellfish of the bottom. I think the big leap of the imagination was to make the switch for deep water diving. Here too, however, any competitive diver (before the day freediving became a sport) with an ounce of curiosity and introspective analysis could not have but noticed the extra degree of lucidity upon surfacing. Moroever, the observation that some animal divers were diving on an exhale goes back a long time. I think, in the end, there is little that is truly revolutionary. Its probably more like incremental realizations. Certainly, both Eric and I have had our fair share of critics and naysayers, but that's a good thing because in the end one shouldn't accept ideas outright, at least not without direct first-hand experience. I know the main protagonists of the day, the french, predictably gave you plenty of grief. It was probably a good thing that so few Italians spoke english at the time, otherwise you probably would have got a double serving.

 

[cdavis]

Thanks guys, fabulous history. You guys, and maybe Rudi, should get together and write a history chapter.

Revolutionary ideas are almost always built on bits and pieces of other people's work. The revolutionary part comes from the ability to put those pieces together into a new insight.

And you know you are on to something when everybody laughs at the idea.

Connor

 

[efattah]

I do recall, around 1995, my dad telling me he had watched a documentary on a tribe of native pearl divers who exhaled their air before going down in order to 'make it easier to get down'. Unfortunately I was never able to track down which documentary or which tribe it was. Nonetheless as my dad knows nothing about freediving I have no reason to believe he was mistaken.

When I did the lung volume calculations in 2001 and figured that max volume was not necessarily the best, the first thing that sprung to mind was those native divers.