PSAI Narcosis Management course - 73m on air

[netmage]

I've been known to hang on a line for HOURS during a dive..

I've even been lazy enough to use a Jon line once or twice

Admit it... You're guilty too

And when I reach the bottom, at the point of the most depth induced narcosis, I go somewhere... swim along a wall, go explore the innards of a wreck... I don't just snuggle up to that line...

Holy crap Mike - you have no idea how true that statement is. Or maybe you've done a dive with Netmage

On the same depth and BT, my gear is usually broken down and I've already called in the lunch order when he finally gets out of the water. To say cats don't like water is just wrong

Thanks pal... I'll use the deco strategies that seem to work for me... Not all of us can pull of VPM+0 day after day... Maybe there's something in that Weston water, or a deco gene you and GI3 share...

 

[Mike Edmonston]

And when I reach the bottom, at the point of the most depth induced narcosis, I go somewhere... swim along a wall, go explore the innards of a wreck... I don't just snuggle up to that line...



Thanks pal... I'll use the deco strategies that seem to work for me... Not all of us can pull of VPM+0 day after day... Maybe there's something in that Weston water, or a deco gene you and GI3 share...

hehe.. you said "snuggle"...

Just to clarify, the only time we hang on a rope is during deco or descending in a bad current. If we're drifting a deep reef, the ONLY thing I'm hanging onto on the way down, are my speargun bands!

Cheers,

 

[rjack321]

I don't have trimix training either (and I'm intending on getting some), but I've been on boats where other divers were diving mix, and I've heard them say that helium is an unforgiving gas, a fast gas, you have to get your stops right every time and so on. They also had to deal with expensive fills if a dive got blown out.

To me, albeit not trimix trained, it seems that helium is like many things in the alien underwater world, a trade-off. And once I have the training, I'll be a better judge of this trade-off. YMMV

Unfortunately pretty much your entire post is erroneous (except the price comment although that can be address by avoiding using "best mix")

Helium does "dissolve faster" but if you explosively decompress (aka miss stops) you really get bent from the nitrogen in the trimix, not the He.
Rubicon Research Repository: Item 123456789/6582

There are alot of benefits to helium and its unfortunate that the myths of the past (e.g. get off the trimix as soon as possible by switching to air at rediculous depths) still linger. All in all helium is a much friendlier gas than nitrogen and trimix is alot nicer to decompress from than even nitrox. So much nicer that some of us are using deco gases like 35% O2 /25% He and 50% O2/25% He for intermediate decompression.

 

[shoredivr]

So much nicer that some of us are using deco gases like 35% O2 /25% He and 50% O2/25% He for intermediate decompression.

That's interesting. Are you carrying both those mixes plus O2, or choosing one of them plus the O2?

Thanks for link.

 

[KMD]

That's interesting. Are you carrying both those mixes plus O2, or choosing one of them plus the O2?

Thanks for link.

It would depend on the dive... but for the most part 35/25 would be used on dives deeper than 200'

Generally speaking 50% is usually the first bottle added, then O2 then the deeper gas.

 

[rjack321]

It would depend on the dive... but for the most part 35/25 would be used on dives deeper than 200'

We have used 35/25 on in the ~240ft range, switching at 120ft, seems to work nicely.

50/25 would depend on the exposure. We are looking at a 35-40 min dive at 190-200ft and considering 50/25 because the He is so much easier on your body than nitrox50%. For shorter dives there's not as much "slow" N2 accumulation so the EAN50 works fine. For the long dives, decreasing the N2 fraction in the intermediate deco gas helps eliminate the N2 sooner (but keeps more He around longer). Once you are on O2, the gradient for N2 to O2 or He to O2 is equally maximal but the He cleans up much faster than the N2.

 

[=C=]

Interesting read. Thanks for the post.

You could improve your safety margins with a double bladder rig.

 

[Tortuga68]

I'll bear that in mind, thanks

 

[jimqh2o]

The "diving community" used to be afraid of Nitrox.

 

[Tigerman]

Be afraid of the voodoo