If you had to choose, 80% or 100% for deco gas and why.

[waterpirate]

To me in my world this is all just too much ego and hubris. We all do what we do, and accept the consequences. Diving left over mix for example on a shallow dive. You make a plan with the gas you have and dive the plan. If it works for you, great.

I dive He for sobriety shallow and do not stress on the He in deco mixes until the 200+. The issue for me there is IBCD. On those dives I want He in my midwater bottles. I have and do re mix deco gas as needed. I test it and dive the plan generated by the results. In the end we all want different results for different dives at different times. This will start the next thread fued. Ideal gasses vs. standard gasses.

Have fun.
Eric

 

[TONY CHANEY]

To me in my world this is all just too much ego and hubris. We all do what we do, and accept the consequences. Diving left over mix for example on a shallow dive. You make a plan with the gas you have and dive the plan. If it works for you, great.

I dive He for sobriety shallow and do not stress on the He in deco mixes until the 200+. The issue for me there is IBCD. On those dives I want He in my midwater bottles. I have and do re mix deco gas as needed. I test it and dive the plan generated by the results. In the end we all want different results for different dives at different times. This will start the next thread fued. Ideal gasses vs. standard gasses.

Have fun.
Eric

So are you in the 80% or 100% group? Hard to tell by your post.

 

[lowviz]

...//... The issue for me there is IBCD. ...//...

Yeah, same. I just blew it off categorically until I read this: http://www.scubaboard.com/forums/di...n-sickness-recreational-dive.html#post6441228

I don't do or plan to do aggressive multi-day diving, I just want a clean and clear 130' - 150' dive now and again.

---> So can I blow off the whole idea of IBCD (in my case) or not???

 

[DuboisP]

100% because it's easier to mix.

depending the availability
80% is acceptable if i cannot have 200 bar in my pony

 

[Ste Wart]

ICD (ibcd? Sounds like an aqualung model) happens on all dives where you switch from trimix to eanx.

Bad ICD is the thing to worry about

Sent from my couch using tapatalk

 

[Dr. Lecter]

---> So can I blow off the whole idea of IBCD (in my case) or not???

This is one of those things where I'm not aware of any great evidence one way or the other. In my diving (50% HE or less, and above 400'), I haven't had a problem coming off bottom mix to 21% in the 200' range even after substantial exposure. Which suggests that the 0.5 ATA threshold V-Planner uses is overly conservative, but far be it from me to call one person's limited anecdote a scientific refutation of the model I'm violating--I'll leave that to AJ. Maybe it's my following the Sheck gas-switching approach when going from mix to air? Can't hurt, but likely just ritual.

I met someone a bit ago who had been trained to dive something like 80/95 and tell his SW his mix had 0% HE rather than the 50% HE it actually had. I know others who've been trained to dive similar mixes using something like 15/125 because of the HE content. A lot ​of this stuff is still a work in progress, no matter what certain agencies teach.

 

[waterpirate]

I did not answer the original question because my preferance is not being discussed. I prefer 70%. I also prefer to put He in my midwater deco gas to counter act a / potential / narcosis hit when coming off a gas like 18/45. Coming off 18/45 I prefer to get on 32/20 instead of 32. My choices have to do more with ease of blending, sobriety, and what works for me. I do not do expedition level diving. The diferance in deco times to me, or speed out of the water, plus or minus 10 minutes is really no big deal to me.
YMMV
Eric

 

[kwinter]

The 0.5 ATA threshold for ICD in V-Planner is a user adjustable factor. But since the data is so sparse, I just leave it there and know when it alerts me. Over the years it has led me to standard mixes (yes, here comes a whole separate thread) that make it easy to just keep my bailouts full and ready.
10/60
14/45
18/35
21/25
32/10
50%
80%

I haven't had any problem, but past performance is no guarantee of future results.

far be it from me to call one person's limited anecdote a scientific refutation of the model I'm violating--I'll leave that to AJ.

 

[waterpirate]

Standard mixes only get a bad rap when they are applied in a arbitrary way. I to have developed my list of standard gasses based on where my favorite charter goes. Keeping my doubles filled with mixes that let me hop on the boat at a moments notice is worth the trade off of it not being the ideal gas for the dive, but one that works without a huge penalty or being to hot or to lean.
YMMV
Eric

 

[Errol Kalayci]

The Hydro Atlantic dive July 18 2014 on Vimeo
neither 80% or o2 used, just 21/35 and 50/15, fun dive