Are there any entry tech courses that include Trimix?

[limeyx]

I thought the original point was: entry level deco, should it include He or not?

I say yes. If you can't dive He cause your ascents are questionable, then there's no reason to be doing deco at all.

Secondly, the last thing I want to be on a deco dive is impaired by narcosis. We all know that leads to bad decisions.

Get the training, develop your skills. Dive safe on the bottom and on the ascent.

100% agreed.

 

[PerroneFord]

Well, you posted the profile to make some kind of a point, only the profile really did not reinforce your statement (that somehow the dive was "OK" on 32% or "more OK" or "less bad" compared to 30/30)

Yes, but it wasn't until AFTER I posted it that I realized it would not illustrate my point as I had screwed up the numbers. So I just let it come to nothing. Some have apparently fixated on it though.

My feelings still stand. If we cannot guarantee the diver in question has bulletproof buoyancy, even under duress, then I do not feel that Helium should be added to the mix. Given that we are talking about divers who are NEW to deompression diving, it stands to reason that they have not yet had a lot of practice in holding stops, particularly under duress.

I am quite certain that the first time I have to shoot a bag from 100ft because something has gone wrong, or perhaps we are sharing a long hose, and trying to do a team ascent in close proximity, and we're drifting away from the boat in current, that my buoyancy might suffer and I might drift 5ft or maybe 10. Since this is the case, I choose not to use a gas that I feel, and my instructors feel, might cause me more harm.

I am certain there are divers out there who FAR exceed my skills, even those new to decompression diving. So perhaps helium is fine for them. Or perhaps it's fine for everybody and all these theories will prove wrong. I don't know.

 

[rjack321]

I am quite certain that the first time I have to shoot a bag from 100ft because something has gone wrong, or perhaps we are sharing a long hose, and trying to do a team ascent in close proximity, and we're drifting away from the boat in current, that my buoyancy might suffer and I might drift 5ft or maybe 10. Since this is the case, I choose not to use a gas that I feel, and my instructors feel, might cause me more harm.

I am certain there are divers out there who FAR exceed my skills, even those new to decompression diving. So perhaps helium is fine for them. Or perhaps it's fine for everybody and all these theories will prove wrong. I don't know.

For my needs, 50% and o2, are working fine, and likely will work fine for many dives to come.

When the poo hits the fan you do not want to be either:
Narced or shooting bags from down around 100ft. Get up to your gas switch, get stable, breathing less gas, and started on the deco. Then shoot the bag.

A 5ft drift at deeper depths (>40ft) is trivial. And by the time you get real shallow, like 8ft, most of you deco is done. Still want to have a controlled ascent. But this concept that bouyancy must be plus minus 6" to use helium is silly.

OK, Now you're talking about 50% and O2??? Since when are we talking about deco gases, I thought this was focused on backgases?

 

[PerroneFord]

OK, Now you're talking about 50% and O2??? Since when are we talking about deco gases, I thought this was focused on backgases?

I gotta stop drinking during the day....

 

[limeyx]

My feelings still stand. If we cannot guarantee the diver in question has bulletproof buoyancy, even under duress, then I do not feel that Helium should be added to the mix. Given that we are talking about divers who are NEW to deompression diving, it stands to reason that they have not yet had a lot of practice in holding stops, particularly under duress.

If you replace ", then I do not feel that Helium should be added to the mix" with "should not pass a decompression class and should not go decompression diving" then we are in agreement

The class is *supposed* to put people under *more* stress than normal to make sure they can hold their stops. The Nitrox/he is (mostly) a red-herring.

 

[rjack321]

BTW, the GUE diver ability standard for rec-triox (30/30) is plus-minus 5 ft of target depth. Which I think is reasonable. I don't know about other agencies, by and large they don't publish their standards anyway.

 

[PerroneFord]

Limeyx, I'll buy off on that change of quote. It more accurately reflects my feelings. I took adv nitrox WAY to early and knew it as did my instructor. I was able to see where the bar was and what was needed to get there. A year later, I was ready to pass it (thank you GUE).

rjack, I had forgotten about the GUE standard. 5ft up and down is a lot of movement. I've been trying to handle tasking in 1ft or perhaps 2.

 

[rjack321]

rjack, I had forgotten about the GUE standard. 5ft up and down is a lot of movement. I've been trying to handle tasking in 1ft or perhaps 2.

While doing an air share??? Shoot man don't beat yourself up.

I aim for within a foot on any "blue water" (it ain't blue around here) ascent. Generally I'm there.

But if I were doing an air share from the bottom (practice, never been forced to this for real) I would not hold myself to that standard. Kinda depends on my buddy, but
while sharing gas:

plus minus 1-2ft doing excellent
plus minus 3ft doing well
plus minus 5-6ft acceptable for triox divers
plus minus 8-10ft acceptable for 32% divers
>10ft bouyancy changes while air sharing means you need more shallow water practice before diving deeper than 60ft.

Just based on what I see fundies, triox, Tech1 divers doing successfully and GUE standards. YMMV

I have no idea how easy or difficult other agencies make their bouyancy standards for adv. nitrox/deco nor MDL recreational trimix.

 

[PerroneFord]

You'll LOVE this...

I was doing buoyancy and skills practice with a new SB member a month ago. We were working in the shop pool. 10ft of water. We'd be working about 80 minutes. She was so intent on her work, that she forgot to check her SPG for a while and her reg started breathing hard. She signaled me with low air, and I donated to her. Asked her if she was ok.. she signals OK back. We ascend.

This was a REAL OOA, in 10ft of water, we were midwater, and this person had less than 10 dives to her name at the time. I think she's gonna do ok! Frankly, I was surprised I held buoyancy that well.

 

[rjack321]

That is funny, OOA in the pool. Good for you not corking

On a sadder note, there was a fatality in the PNW a few months ago. RB diver gets in a shop pool to "use up some gas" Doesn't turn on the ppO2 sensor on his Dolphin. Breaths tank down, stays on loop. Passes out in 10ft of water and drowns.