I wonder how many people had to die before we "discovered" that we needed a combination of 3 gases and not only oxygen in order to go deeper into the ocean....fascinting
Kahuna76: I believe they use heliox or helitrox for much shallower dives. Helium cause so called (HPNS) high pressure nervous system syndrom when you body shakes uncontrollably. So Nuno used trimix for his deep dive he still talks a lot in the film about HPNS syndrom that he had at that depth.
Oxygen is posionous if the body has too much. On the surface most people can breathe it 100% without any ill effects. As depth increases the "partial pressure" increases. Oxygen has a partial pressure of 0.21 on the surface... at 10m roughly 0.4. BSAC sets a standard that says you shouldn't take more than 1.4 partial pressure otherwise you're likely to get oxygen poisoning where you will have spasms and fits likely drowning you if not solved.
Oxygen at depths of around 60 metres becomes toxic, Nitrogen around 40 - 50 metres (depending on the person) becomes narcotic so there are less of them and helium will only be hazardous at very low depths causing the shakes, as she said. I believe Nitrogen swells tissues around the nerves causing a loss in function (cognitive and motor); Helium does the opposite and shrinks the tissue which can cause them to fire 'randomly' causing the shakes. Both cancel eachother out (to an extent!)
there would also be the possibility to dive with hydrogen mixtures wich would allow for bigger depths with less Sideeffects. BUT hydrogen and oxygen become highly explosive.. the security measures would've been enourmous and probably unaffordable :)
Oxygen toxicity rarely occurs, but nitrogen narcosis can. Rebreathers that fail to supply the swimmer with the proper amount of each gas in a mixture of breathing gases can be fatal To the swimmer. .rebreathers must be checked carefully and calibrated often. , daily.
cool i didn't even know there where other breathable compounds like diferent forms, they should go into more detail because i find this very interesting, btw i understood you/commentator perfectly :D
The problem with ordinary scuba diving is that nitrogen inhaled underwater dissolve s into the blood stream of the swimmer at any depth , when breath ed from a scuba regulator. This dissolved nitrogen must be eliminated from the divers’ blood stream , during and after the ascent , at end of the swim. Nitrogen in supersaturated amount s forms tiny bubbles in body tissues and blood vessels. , clogging the capillaries, veins and arteries. The use of another suitable gas for underwater breathing during scuba dives, solves that problem, decompression is easier than with nitrogen-oxygen mixed gas , known as ‘air’. Decompression is easier with Helium-oxygen mixed gas or also with Heliun-oxygen-nitrogen. Tri-mix. The decompression times ina recompression chambet topside ona ship or a beach is less.
I'm not a tech diver, but don't they use Heliox (just O2 and helium without the nitrogen) at depths like that or do you need a rebreather for stuff like that?
I wonder how many people had to die before we "discovered" that we needed a combination of 3 gases and not only oxygen in order to go deeper into the ocean....fascinting
Sheck Exley’s book “Caverns Measureless to Man” speaks about it quite a lot. If you’re a diver I highly recommend reading it...
Kahuna76: I believe they use heliox or helitrox for much shallower dives. Helium cause so called (HPNS) high pressure nervous system syndrom when you body shakes uncontrollably. So Nuno used trimix for his deep dive he still talks a lot in the film about HPNS syndrom that he had at that depth.
Oxygen is posionous if the body has too much. On the surface most people can breathe it 100% without any ill effects. As depth increases the "partial pressure" increases. Oxygen has a partial pressure of 0.21 on the surface... at 10m roughly 0.4. BSAC sets a standard that says you shouldn't take more than 1.4 partial pressure otherwise you're likely to get oxygen poisoning where you will have spasms and fits likely drowning you if not solved.
Oxygen at depths of around 60 metres becomes toxic, Nitrogen around 40 - 50 metres (depending on the person) becomes narcotic so there are less of them and helium will only be hazardous at very low depths causing the shakes, as she said.
I believe Nitrogen swells tissues around the nerves causing a loss in function (cognitive and motor); Helium does the opposite and shrinks the tissue which can cause them to fire 'randomly' causing the shakes. Both cancel eachother out (to an extent!)
there would also be the possibility to dive with hydrogen mixtures wich would allow for bigger depths with less Sideeffects.
BUT hydrogen and oxygen become highly explosive.. the security measures would've been enourmous and probably unaffordable :)
@Kynokeh
why is it always native english speakers doesn't understand each other? for not native speaker (as I'm one) she speaks really clear.
Yes, the video is very informative, I agree!
Christoo92: Sure! That's all described in the theory of technical diving (try TDI manuals)
@overseasmedia Hi, where can I find this documentary ?
Thx a lot / Erik
Oxygen toxicity rarely occurs, but nitrogen narcosis can. Rebreathers that fail to supply the swimmer with the proper amount of each gas in a mixture of breathing gases can be fatal To the swimmer. .rebreathers must be checked carefully and calibrated often. , daily.
cool i didn't even know there where other breathable compounds like diferent forms, they should go into more detail because i find this very interesting, btw i understood you/commentator perfectly :D
watch the film "SPHERE" and you will understand more about deep sea diving and why Helium is used.
Where to buy or get (depends on licensing) Beyond Blue documentary?
The problem with ordinary scuba diving is that nitrogen inhaled underwater dissolve s into the blood stream of the swimmer at any depth , when breath ed from a scuba regulator. This dissolved nitrogen must be eliminated from the divers’ blood stream , during and after the ascent , at end of the swim. Nitrogen in supersaturated amount s forms tiny bubbles in body tissues and blood vessels. , clogging the capillaries, veins and arteries. The use of another suitable gas for underwater breathing during scuba dives, solves that problem, decompression is easier than with nitrogen-oxygen mixed gas , known as ‘air’. Decompression is easier with Helium-oxygen mixed gas or also with Heliun-oxygen-nitrogen. Tri-mix. The decompression times ina recompression chambet topside ona ship or a beach is less.
deighton2002: Hi there, as you can see we corrected He, thanks once again for the comment!
Christoo92: because at depth O2 has a narcotic and poisoning effect on human body
Im curious, could you use a trimix with 21% o2 and then a nitrogen, helium mix and do a recreational dive to 40m ? Any advice would be good
Thanks
u could if u had the money but there is no point air is fine for that shallow depth
I'm not a tech diver, but don't they use Heliox (just O2 and helium without the nitrogen) at depths like that or do you need a rebreather for stuff like that?
Hydra Comex Dive?that was 350m?
@armandin2048 maybe she said :narcotic effect. ??
hi, very informative videos, but Helium is He not He2, two hydrogen atoms can't join together in the way hydrogen oxygen or nitrogen do.
Kynokeh: From South Africa (watch my "Beyond Blue" documentary)
@Asartex totally right you too, whatever that means
Decompression must be. Enhance d. In these cases .
m91arc: South African!
that's interesting!
Do you know how exactly it would poison someone?
awsome vid!
👍
its understandable...
why would pure Oxygen poison him?
tks nice video
@danielfu79 i understand that and im from germany!
you can't understand what she's saying.. where is she from?
Since when was helium a diatomic gas? Cute :-).
Oh hi
@armandin2048 hahaha nah buddy im spanish.
I don't understand her... that accent!
terrible accent