Future of OC trimix

[Marie13]

Yep, going to 145! Even if it is just a dive to figure out they don't want to do that again. If a student already knows they get a bad narc at 130, it is their responsibility to call the dive beforehand. If they can't be responsible enough to do that in class, they certainly won't be responsible enough to do outside of class.

I WOULDN'T do a 145' dive on air when the bottom is at 350 though... Need a bottom around to keep them from doing something TOO stupid.

I think Wibbles point was you don't have to be going to mix depths to be doing deco.

It’s a former open pit mine with roads and walls at various depths. A dive to 150 means the bottom at that point is about 150-160.

My point was that this insistence for AN/DP before going CCR is dangerous when helium isn’t available and students are narked bad even within recreational depths. I sure as hell won’t be doing ANY dives to 150 on air. If I can’t get helium, I won’t do them.

 

[formernuke]

. If a student already knows they get a bad narc at 130, it is their responsibility to call the dive beforehand.

Or to take trimix/helotrox at the same time and do the dive on trimix instead of air or nitrox.

 

[Marie13]

Or to take trimix/helotrox at the same time and do the dive on trimix instead of air or nitrox.

The sticky point is if helium isn’t available…

 

[formernuke]

The sticky point is if helium isn’t available…

It is available, just expensive. I live in the same area as the op and can give several places that will teach OC trimix. I know a few that only combine AN, DP, and trimix

 

[Marie13]

It is available, just expensive. I live in the same area as the op and can give several places that will teach OC trimix. I know a few that only combine AN, DP, and trimix

You have it locally available. I don’t.

 

[flymolo]

Can’t you do OC tech diving at 35m/115ft on nitrox?

Hour on the bottom and 30mins decompression with accelerated deco?

OC tecreational diving*

 

[Wibble]

You don’t need to do trimix depths to do ANDP.

It’s the Advanced Nitrox, i.e, rich in oxygen, that you need to know. NoTox, labelling, oxygen clean, switching gas, stowing hoses, etc.

It’s the Decompression Procedures that you need to know. Planning and running to that plan, handling failures, fallback planning, etc.

Helium is virtually insignificant against those two, especially at the shallower 45m/150ft depths. Yes, it reduces narcosis and has an effect on decompression timings, but nothing to learn and practice in comparison with AN and DP.

Which is why you need ANDP prior to the one dive more for Helitrox.
(Do you need an additional dive for helitrox? I’m not an instructor and it’s a few years (6?) since I did ANDP+helitrox)

 

[Mergulhador do Delray]

Here is some recent news about helium production. Though it is pre-Ulraine War so it doesn't account for Russian sanctions.

Helium markets now experiencing ‘Helium Shortage 4.0’

When helium markets tightened up during the second half of 2021 due primarily to a four month maintenance outage of the US Bureau of Land Management's (BLM) crude helium enrichment unit, the industry consensus was that Gazprom's Amur project would begin pumping large quantities of helium into...

www.gasworld.com

 

[Tracy]

It’s available enough. It might cost money, but…. So? It’s an expensive sport.

I don’t think anyone is advocating to stay on OC forever, but dang do SOME oc tech stuff.

The “skip it” mentality is dumb imo.

It is currently not available at all. BLM has allocations set at 20% currently to essential infrastructure. If medical facilities can only get 20%, there is none going to non essential until at least June currently. That is if BLM changes allocations at that point. Shops that have it on hand can do as they want with it, but it is not currently available to restock.
There are work arounds for everything, but that doesn't make it "available enough." That makes it available to people that know people.

 

[Marie13]

You don’t need to do trimix depths to do ANDP.

It’s the Advanced Nitrox, i.e, rich in oxygen, that you need to know. NoTox, labelling, oxygen clean, switching gas, stowing hoses, etc.

It’s the Decompression Procedures that you need to know. Planning and running to that plan, handling failures, fallback planning, etc.

Helium is virtually insignificant against those two, especially at the shallower 45m/150ft depths. Yes, it reduces narcosis and has an effect on decompression timings, but nothing to learn and practice in comparison with AN and DP.

Which is why you need ANDP prior to the one dive more for Helitrox.
(Do you need an additional dive for helitrox? I’m not an instructor and it’s a few years (6?) since I did ANDP+helitrox)

No additional dives needed for Helitrox when combined with AN/DP.

I will say it again. Asking a student who gets severely narked at 130ft to go to 150ft for training dives on air **because helium is not at available at all** is stupid and dangerous. Doing AN/DP open circuit on air would not be a good idea for me. Can’t help it that I’m unlucky with helium unavailable.