Northwest Dive Club

... running out of air at 200 feet is not my idea of "fine" ... it indicates, particularly in a diver with that kind of experience, a mental lapse of monumental proportions.

... Bob (Grateful Diver)

Grateful Diver wrote:... running out of air at 200 feet is not my idea of "fine" ... it indicates, particularly in a diver with that kind of experience, a mental lapse of monumental proportions.

... Bob (Grateful Diver)

You can't blame the diver... It was the narcosis. :-)

loanwolf wrote:He swam back to 190 on the bottom came up to 80 did his transition even took the time to switch his computer. Problem was he did not have enough weight on him to stay down. He was on deco for some time and as he explained to me at one point he was head down swimming trying to stay down. And if you look at the profile on his computer he was yoyo'ing for quite some time before finally popping.

It comes down to if he had the weight on to stay down he would have been fine.

Yep, thats kinda how russian roulette works.. you are "fine".. until your'e not..

kdupreez wrote:

loanwolf wrote:He swam back to 190 on the bottom came up to 80 did his transition even took the time to switch his computer. Problem was he did not have enough weight on him to stay down. He was on deco for some time and as he explained to me at one point he was head down swimming trying to stay down. And if you look at the profile on his computer he was yoyo'ing for quite some time before finally popping.

It comes down to if he had the weight on to stay down he would have been fine.

Yep, thats kinda how russian roulette works.. you are "fine".. until your'e not..

Yep, no different from a lot of sports when you push the extreme limit of things.

loanwolf wrote:

kdupreez wrote:

loanwolf wrote:He swam back to 190 on the bottom came up to 80 did his transition even took the time to switch his computer. Problem was he did not have enough weight on him to stay down. He was on deco for some time and as he explained to me at one point he was head down swimming trying to stay down. And if you look at the profile on his computer he was yoyo'ing for quite some time before finally popping.

It comes down to if he had the weight on to stay down he would have been fine.

Yep, thats kinda how russian roulette works.. you are "fine".. until your'e not..

Yep, no different from a lot of sports when you push the extreme limit of things.

I don't think I would call a 200 foot dive the extreme limit of things.... Well, unless of course you consistently do it on air. But there is simply no need to do that.

Greeves0844 wrote:i just know he offers a course in how to effectively manage Narcosis

You can't effectively manage narcosis. The biggest problem isn't the nitrogen, its the viscosity and density of the gas, that increases the work of breathing and the risk of overbreathing your regulator at depth and building up CO2. Once that build up starts you'll get into a vicious cycle and the CO2 will make you breathe harder and less effectively and build up more CO2 which will increase your narcosis by an order of magnitude over the nitrogen narcosis you were feeling at depth, magnifying your anxiety and eventually spiraling into a full-blown CO2 hit. The problem is that you can do 100 dives and not cross the line and feel that you can 'manage it' but if you ever cross the line then you're not coming back. Helium both decreases the narcosis of the gas that you're breathing and it lowers the gas density and viscosity of the gas you are breathing at depth, that makes it easier to breathe off your regulator and you can clear your lungs easier and you build up less CO2.

As for the military equivalent training, I am an Artillery Marine, and all of my training in manual gunnery applies which most of the manual artillery dates back to WW2, yes there have been updates and we have digital systems that change how we shoot, but at any time i can still accurately engage without the use of a computer. Many marines of the older generations still would rather use this method instead of the digital systems, i look at this the same as deep air, can you still dive deep air? yes you can, nothing stops you from doing this other than evolution of diving which has changed this to no longer be the practice, and is even ridiculed, is there more risk yes, can it be managed if you understand why there is more risk, yes I believe you can.

Deep air is more like Marines who come back, driving sport bikes suicidally because their risk tolerance is off.

They've actually quantified how dense is too dense now. Was presented at the Eurotek conference. Summarized in post 22 here http://www.ccrexplorers.com/showthread. ... ht=density

This is for CCR diving so its a bit uncertain how the 5.2 g/L threshold might apply to OC. Air is 5.2 g/L at about 110ft, air is 6.2 g/L at 137ft.

Nice CCRx thread. Simon Mitchell's post earlier in the thread is also a good read:

http://www.ccrexplorers.com/showthread. ... post170477

(assuming that URL works, either my chrome or their website is being stupid for me, I'm talking about post #10...)

As a slight follow up, for those who don't think that the resistance and WOB is 'all that big a deal' because you don't notice it when diving... Here is a bit of food for thought.

When I worked as an UW grip a few months back and 10+ hours of an 18 hr day were spent underwater about 50% on OC and 50% on CCR, for the next 3 days my breathing muscles were sore. Literally my breathing muscles. At no point during the dive day did I feel like I was breathing hard, it all felt like normal resistance. The muscles (my intercostals and diaphragm) felt like i'd been to the gym and lifted weights with them. It was not my 'lungs hurting' from dry air, my lungs felt totally fine, it was the little muscles you use when deep breathing/coughing/laughing.

I don't get sore breathing muscles from sitting here at my computer breathing all day so the only thing I can attribute it to is the work of breathing underwater. My OC regulators are all high performance and well tuned. My CCR has a radial canister and low WOB top of shoulder lungs. Max depth was 12'.

My take home from this is that even with good regs and low resistant loop, there is 'work' when you breathe underwater, even in shallow depths.

ljjames wrote:...for the next 3 days my breathing muscles were sore.

I'm curious, did you experience more so during inhale or exhale. I ask because as respiration was once explained to me, you use muscle to contract the diaphragm and expand your lungs, creating a vacuum so that the outside air rushes in to equalize the low pressure in the lungs. When you exhale, you simply relax all your muscles and spring tension (my words) pushes the air out. The application was that exhalation resistance will cause pain very easily because we are not used to using any muscles to exhale. Apparently, we can tolerate inhalation resistance much easier.

What was explained to you was respiration on the surface, correct?

My breathing muscles in both directions were sore, when I pressed on them between my ribs and upper chest, they were tender.