Rec Trimix

[TheRedHead]

Possibily so, Lynne. Nitrox over 40% is still considered too dangerous for recreational divers. How do you feel about that?

 

[JeffG]

I'd really like to go back there and dive it again with doubles, 30/30 and work on running line inside it... We were planning on doing that a month or so ago, but it fell through...

That is a very cool dive. Its what we did last december. Tied off a line and go to the kitchen. I was using 21/35...I would never do that dive on Air/Nitrox.

 

[Soggy]

Possibily so, Lynne. Nitrox over 40% is still considered too dangerous for recreational divers. How do you feel about that?

It's not that nitrox over 40% is inherently too dangerous for recreational divers, it's just that nitrox percentages higher than 40% are generally used as decompression gasses. Who needs EAN50 for a 60 ft dive? I'd have to sit down and do the math, but I'm pretty sure the NDL would be near infinity and the OTUs would go through the roof. Everything you need to know about using any nitrox mixture is taught in a basic nitrox class, but there is no benefit to using rich mixes in recreational diving.

 

[TheRedHead]

Those gases are dangerous and forbidden to recreational divers. :evil:

 

[lamont]

That is a very cool dive. Its what we did last december. Tied off a line and go to the kitchen. I was using 21/35...I would never do that dive on Air/Nitrox.

yeah, It'd be nice to take 21/35 and a 70 foot bottle and stay down there longer than the NDLs, too...

 

[JeffG]

yeah, It'd be nice to take 21/35 and a 70 foot bottle and stay down there longer than the NDLs, too...

We did 40min BT

 

[limeyx]

I don't want this to turn into a flame war. Would someone please explain to me if Tech1 incorporates Advanced Nitrox where one would make deco dives on air using a rich Nitrox mix slung?

no GUE course, including Tech 1 teaches this.
For GUE, the standard gases for any depth deeper than 90 or 100 feet include triox/trimix. 30/30 and 32% overlap somewhat in the "recreational" range of diving.

 

[limeyx]

*sigh*, helium is not the central bit to the rectriox class. most of it was dealing with failures, keeping the team together, buoyancy and trim, ascent drills, mask off drills, mask off ascents, etc. its not a 'c-collector' class. if it were just about breathing helium it'd be composed of gas filling, analyzing and a little instruction not to ascend too fast....

and if you'd like to go on a dive at 100 fsw where helium makes a difference, I can arrange -- particularly after the spring plankton blooms hit here and the viz goes...

Agreed, same thing with Tech1. day 1 and two are spent below 60 feet or so, dealing with exactly the same things lamont quotes above.

Day 3 and 4 essentially incorate some deeper stuff (around 90 feet in our case) and you have to do a lot of the above in mid-water (where you cannot see the bottom)

We dived 30/30 on day 4, and the only time we went below 100 feet was for our two experience dives.

It's mostly about building and evaluating the skills needed to safely dive deeper, longer etc.

 

[limeyx]

You missed mine too. There is an argument to be made that diving Helium on a lot of dives at 100 feet is not necessary for a safe dive. My instructor was not making an argument for deep air. 100 feet is a recreational dive. Why not Nitrox? That was my original point which seems to have gotten lost.

I think as Kevrumbo said (making a good point), it depends what you are doing at 100 feet.

If you are penetrating a wreck, diving in cold water, have a specific task to do (video maybe) that requires a clear head, then 30/30 may be the better choice.
30/30 also allows you to dip down to 110 or 120 feet for the first few minutes of the dive, while still having narcosis depth shallower than 100.

If you are expecting a more relaxing dive, nitrox 32% is fine -- it's all about making good choices.

The cost of the gas compare to the risks to your safety from picking the wrong gas is not a consideration in my case. Pick the right gas for the job, and then if it's too much $ change the dive you are planning or dont dive it.

 

[Kevrumbo]

I'll dance with you, sugar.

Thank You my new Cyber Dive-Buddy & Friend!:winky:
Kudos to you for bringing out some of the heavy hitters from the Tech Dive Forums with some good info. --and with somewhat civil attitudes to boot as well!
I'm surprised that the Boogeyman, MHK himself, hasn't materialized here yet (don't invoke his name three times! Michael Kane. . . Michael Kane . ..Michael ~~:vampire