9 replies to this topic

[Diverbrian]

For those of you who used to dive deep air and now dive mix, I have a question.

I have noticed since I dive mix more that I feel less tolerant of narcosis than I used to. I mean that I didn't used to think anything of taking EAN28 to 130 ft. Now, I tend to dive 28/20 or 28/10 to that depth to cut down on the narcosis and notice that the level of narcosis that I feel at 130 on nitrox mixes (when I don't have mix available) is enough to bother me again. This isn't as serious as it sounds but I just notice that the dives that I used to do are almost unthinkable without helium in the mix.

The primary reason that I mention it is that there are warm water locations with reasonable 150-180 ft. dives that are nice. You can get doubles and deco mixes, but many of these places are remote enough that helium isn't happening. Once upon a time, I may have considered diving these locations, but now I get the impression that I wouldn't due to the lack of mix availability.

[PerroneFord]

How hard would it be to ship a 130 full of helium over and cascade it? If you're only trying to get 20% helium in your mixes, you should be able to get at least 2-3 dives off that.

[gcbryan]

I don't think you can ship a full tank can you? I think you have to ship with the valves removed.

[Diverbrian]

How hard would it be to ship a 130 full of helium over and cascade it? If you're only trying to get 20% helium in your mixes, you should be able to get at least 2-3 dives off that.

It's not as easy as you think. Besides, I would have to get permission to operate someone else's air station which becomes a liability issue. Shipping compressed gas with all of the appropriate safety measures is pretty expensive. This why nitrox is pretty darn expensive in island areas like the Turks and Caicos.

Also, when I am diving to the deeper depths, I do put more helium in the mix. You are looking at roughly 40 percent for deeper dives.

My point was that dives that used to be very doable on standard air to me are not so doable to me on that mix now. This is almost a disadvantage to using helium. I have started to become uncomfortable below 100 ft. without it and that makes diving much more expensive to me.

[ScubaDadMiami]

The issue might be that you had not been narked in so long that even a small bit felt like more than you remembered. So, it might be that the only difference is that you used to dive like this so much that you stopped noticing it.

Perhaps age, conditioning and the like also plays an effect. That would also seem to make sense. Hey, I can't do a lot of things like I used to! Luckily, I am even better at others.

Luckily, Helium is my friend. We get along great together.

[Diverbrian]

Helium is my friend as well . It would be a better friend if were a little less expensive to buy though .

I think that it is more of the first issue in SDM's post than the others. After so long since I have had to deal with serious narcosis, I am simply noticing it more on the few times that I have been in a position to experience it.

I haven't reached the age range where I seriously have to ask myself if my body can do things anymore. I am not in superb physical condition, but I am in good condition and the only time that I was in better shape was when I left boot camp in Orlando, FL and I tore out a knee to do that much running .

[6Gill]

A friend came back from 10 days of CCR diving in Grand Cayman we then did a local dive on 32%,max depth 90ft with about 20ft vis but dark(PNW) he said he felt off his game,wasn't happy at depth thus had depth moved up to 70ft were he felt better but not great.


Helium...the crack cocaine of the deep

Edited by 6Gill, 18 May 2006 - 10:12 PM.

[PerroneFord]

LOL, he'd probably been diving with an END of 10-20ft. Moving to 75 would have been downright scary!

Too funny.

[drbill]

While I don't dive mixed gasses (other than air) yet, friends that do suggest that when you begin diving them you start realizing how narced you really were before. Perhaps this is what is happening here. If you return to diving something other than trimix, you may have this realization.

[Walter]

There is no tolerence to narcosis. OTOH, if you are narced often, you do learn to deal with it more effectively.