Deep diving advice that goes against conventional thought?

[jadairiii]

10 to 20 grand extra a year for me to dive mix keeping my EAD to 100' not to mention the logistics of have 3-4 divers worth of He on the boat.I'm thinking 2-3 Ts each for a typical trip.Not likely to happen.Nor have I seen any evidence of anyone improving in ability on gas at the depths we dive.

In a world where I win the lottery I will dive 16/25 or so all day long for a different reason,increased PON and PO2 are likely complicit in necrosis in joints.

I think the issue here is that your diving is more than hobby. I would never tell a driver to walk around their car on I95 yet for years I did towing and recovery and did it daily. I accepted the risk as part of my job, if I broke down now, I would walk 25 yards away and let the pro's handle it. My buddy is on a salvage boat in Dutch, they go out in 40' seas, its their job, he would not consider doing that for "pleasure".

I dive for fun as do the majority of divers on this forum. So when doing it for fun, I want to stack the cards in my favor.

 

[Storker]

Storker,I kill things for a living Plz forgive my lack of judgement.I assumed N bubbles could come out of suspension blocking flow.

Sorry myself. I just read what you wrote ("molecule") and didn't assume you used the wrong terminology. An N2 bubble might well be comparable in size to a human capillary. An N2 molecule, OTOH, is about 3 Ångstroms in diameter while a human capillary is 5 to 10 micrometers in diameter. In that case, we're talking of a ratio of sizes in the range of roughly ten thousand, which might explain my somewhat... categorical wording.

BTW, I'm not a medical doctor, so take anything I say about medicine with a grain or twenty of salt. But I do know my chemistry

 

[100days-a-year]

My bad,I used incorrect language.I have no problem being chastised,it is invaluable as a learning tool.

 

[DCBC]

I believe the effect of nitrogen on red blood cells refers to aggregation and not to rigidity. Cell aggregation in diving most often relates to the decompression load degree and is mitigated by the diver's condition. DIC (Disseminated Intravascular Coagulation) can also result in diver injury as a complication of DCS. A Fibrin-Fibrinogen Degradation Products (FDP) blood analysis is sometimes used to screen divers for this problem.

Because of cell aggregation, it's common practice for saturation divers to take Aspirin or other Antiplatelet medication throughout their dive. Some studies were undertaken in the early 70's that substantiated this practice. Again this has to do with decompression and not IGN.

---------- Post added March 18th, 2014 at 10:51 AM ----------

When asked by Mike Menduno of aquaCorp in an interview about Deep-air, Sheck Exley responded:

"Now days, the only rational recommendation is to build yourself up to where you can do your air dives to 200 feet; than after 200 do your helium diving. There's no longer any point to build ourselves up to 300 foot dives on air, because most people can't possibly handle it to that extent; it's just one of those individual things. Trying to build up beyond 200 feet, you're taking chances. Maybe you can handle it, maybe you can't."

Sheck completed thousands of dives on Deep-air and set a depth record in 1971 of 142M (465 FSW), which was broken by Bret Gilliam in 1993 and again by Dan Manion in 1994... It's interesting to note that Sheck died while diving Trimix not on Air.

As I've mentioned previously, there's much more to deeper diving than the mixture. Dive within your personal safe diving envelope. Confidence and competence will increase with training and experience. There's no hurry. Safe diving!

 

[danvolker]

I believe the effect of nitrogen on red blood cells refers to aggregation and not to rigidity. Cell aggregation in diving most often relates to the decompression load degree and is mitigated by the diver's condition. DIC (Disseminated Intravascular Coagulation) can also result in diver injury as a complication of DCS. A Fibrin-Fibrinogen Degradation Products (FDP) blood analysis is sometimes used to screen divers for this problem.

Because of cell aggregation, it's common practice for saturation divers to take Aspirin or other Antiplatelet medication throughout their dive. Some studies were undertaken in the early 70's that substantiated this practice. Again this has to do with decompression and not IGN.

---------- Post added March 18th, 2014 at 10:51 AM ----------

When asked by Mike Menduno of aquaCorp in an interview about Deep-air, Sheck Exley responded:

"Now days, the only rational recommendation is to build yourself up to where you can do your air dives to 200 feet; than after 200 do your helium diving. There's no longer any point to build ourselves up to 300 foot dives on air, because most people can't possibly handle it to that extent; it's just one of those individual things. Trying to build up beyond 200 feet, you're taking chances. Maybe you can handle it, maybe you can't."

Sheck completed thousands of dives on Deep-air and set a depth record in 1971 of 142M (465 FSW), which was broken by Bret Gilliam in 1993 and again by Dan Manion in 1994... It's interesting to note that Sheck died while diving Trimix not on Air.

As I've mentioned previously, there's much more to deeper diving than the mixture. Dive within your personal safe diving envelope. Confidence and competence will increase with training and experience. There's no hurry. Safe diving!

Except he started that fateful deep dive, on very deep air.....that created an initial O2 issue, and a high narcotic level unmatched by our present ideas of a trimix dive....and even the end he used for his trimix, was no where close to what any of us use today.....

I know you just said that "people" knew better about HPNS ....probably in the military.....back in the early 90's....but I think it is quite possible that Sheck had an incorrect belief about what would happen to him on something closer to a heliox mix at 800 or 1000 feet deep....It sounds to me like he was using deep air, to mitigate the effects he was afraid of from Helium at depth.....What do you think?

 

[boulderjohn]

....It sounds to me like he was using deep air, to mitigate the effects he was afraid of from Helium at depth.....What do you think?

When we talked about it, Gilliam did not mention anything about Sheck starting the dive on air, but he did say that he was using trimix rather than heliox because of a concern about HPNS.

 

[tomfcrist]

From the accounts I have read it was Heliair 6....Poor mans Trimix.

 

[boulderjohn]

From the accounts I have read it was Heliair 6....Poor mans Trimix.

That's what I understand as well. It may be poor man's trimix, but it is still trimix. My understanding is that the "poor man" part comes from the ease and expense of blending it.

EDIT: When I posted this, I lost track of what thread I was in. The last few posts, including mine, are not appropriate to this thread and should have gone in the thread dedicated to Exley's incident. IN that thread, I just added specific information related to what he was breathing and the dive plan they were following. Let's move this discussion back there where it belongs.

 

[Akimbo]

Let’s see. You want enough Nitrogen to mask HPNS symptoms but not enough that you do really stupid things? I know it sort'a works but doesn’t help compression pains (Compression Arthralgia). You have to wonder how many of the deep Scuba diver deaths over the years was because they hurt too much to swim up, regardless of the breathing mix.

 

[danvolker]

Let’s see. You want enough Nitrogen to mask HPNS symptoms but not enough that you do really stupid things? I know it sort'a works but doesn’t help compression pains (Compression Arthralgia). You have to wonder how many of the deep Scuba diver deaths over the years was because they hurt too much to swim up, regardless of the breathing mix.

This "Compression Arthralgia" is something I have never experienced, even on dives when I had high workloads at 280 feet --on air or trimix.
Wondering why it appears in some divers and not in others. I do think this is why some deep divers use scooters, so the effects of this are less significant in performing the dive....and maybe less exacerbated--as I have heard some divers say they feel better after the dive if they do less work on it...again, I don't experience this, so it is alien to me.