Helium/Trimix for Recreation limits???

[sheahanmcculla]

This just got too complicated for me But thanks for all the help!

Step 1: Get the gear needed for an intro to tech 1 class, or helitrox. I believe I would need
Argon Set up
Non split style fins
Back plate/harness
Doubles
High performance regulator-with long hose
(This list might take me awhile)

Step 2: Look for a good class to take and talk to the instructors.

Step 3: See boat at Mukilteo


Thanks Again for all the help! I am sure I will be contacting some of you in the future for more info.
Sheahan

[Nwbrewer]

This just got too complicated for me But thanks for all the help!

Step 1: Get the gear needed for an intro to tech 1 class, or helitrox. I believe I would need
Argon Set up
Non split style fins
Back plate/harness
Doubles
High performance regulator-with long hose
(This list might take me awhile)

Step 2: Look for a good class to take and talk to the instructors.

Step 3: See boat at Mukilteo


Thanks Again for all the help! I am sure I will be contacting some of you in the future for more info.
Sheahan

Sheahan there were other suggestions for you buried in this thread. I think for you step 1 would be get the IP checked on your reg to make sure it's not too low. Step 2 would be to dive more, make sure that you're breathing is deep and even. See if these two take care of some of your narc issues. Step 3, do some moderately deep dives, take a gas management class so you know what you're doing gas plan wise going deep. Track your RMV. If it going through the roof on the deeper dives that (to me) points to anxiety and the corresponding increased breathing rate that's not going to help your narc.

Then start thinking about the other stuff.

Plus, as someone whose seen the boat at Mukilteo, I recommend going to EUP. There's an identical one there at about 40' that you can spend all day on with no narc at all. And there's more life on it too.

Jake

[LCF]

I'm pretty sure you can take Helitrox in a single tank setup, and I know you can take GUE Fundamentals and Rec Triox that way.

[loanwolf]

one thing to keep in mind. Trimix can penalize you with more deco at shallower to moderate depth than you will get with air. This is due to its lighter molecular weight. Your body on gasses it faster than nitrogen. On the flip-side it also offgasses faster. Higher mixes of He at shallower depth will not benefit you but it will penalize you. I see this every time I dive with a air diver on shallow to moderate depth dives. I run 10/50 in my mCCR all the time. I will rack up a considerable amount of extra deco time over the air diver. Its is all He. Now when i start to deco the time will run off exponentially faster depending of what the gradient factor is set on your computer. When you get into decompression and trimix classes you will learn far more about the compartments of the body and gas saturation.

That said, He in low mixes is good. Do not think if a little is good more is better.

This is one of the controversies surrounding the use of helium breathing gas mixtures. It’s not quite that simple. This is where it pays to see the whole picture (or at least what we believe the whole picture to be today). You are most likely talking about Bühlmann ZHL-16. This theory uses Graham’s law (molecular effusion which involves the movement of one gas at a time through a hole) for its M-value calculations, which states that Helium saturates 2.65 times faster than Nitrogen. The problem is that the theory doesn’t take in to account the other law involved, Henrys law, which deals with the solubility of gases. Helium is A LOT less soluble than nitrogen. Think sugar (Nitrogen) compared to sand (Helium) dissolved in water. So yes the helium that actually dissolves in the tissue dissolves 2.65 times faster, but the question is “how much actually dissolves?”

There are also thermal conductivity and Isobaric counter diffusion issues surrounding the use of helium. The nice thing about recreational helium use is that you don’t necessarily have to understand why it works to use it safely. Recreational Helium is table based diving. Just like nitrogen based tables, the helium tables are VERY conservative. The NAUI Helitrox RGBM tables are built to handle a 60 ft ascent rate (30 ft still recommended).

The discussion portion of the recreational Helium class tries to give you background information, benefits, and possible concerns for breathing helium mixtures. The application portion of the class stresses the skills and protocols need to execute the dive safely.

Scott

I did not see any reasons as to go into theory on this thread as the theory is not taught in detail as you stated in recreational trimix. But it is something to be aware of. More is not always better when it comes to He.

As I posted on this one we were deviating too much for this thread topic. If you want to go into detail lets start another thread with this and talk about molecular weight permeability and solubility. We are not helping the originator with their question. As Jake summed up and I mentioned earlier.

1) Check the IP of your regulator.
2) A shop can also run a mag test on it and measure the draw and on most good regs this can be adjusted.

Testing the IP will tell you a lot, almost always if the IP is good the Mag test will be good as well. I have seen several just serviced regs for different shops that had too low of IP pressures before. It is not a uncommon thing to happen. If you do not have the capability to do a IP test yourself "take it to a different shop than the one that serviced it and get it checked". I think a IP gage is a integral part of a took kit. I check mine all the time, and form time to time have to adjust it to get it back on track, they will vary a little. especially if you dive a great deal or you toss it in the closet and drag it out once ever 2-3 months to dive.

I myself for the past 30+ yrs of diving have service all my own equipment. It is my life support, it goes to the analogy of a pilot or a skydiver in my mind. You had better pack your own parachute or dam well trust the individual that is packing for you, you life is in their hands at that point. their are only a few out their that I would trust.

[dsteding]

We are not helping the originator with their question.

I'd disagree. There are some fundamental differences in people's attitudes towards helium, an old-school attitude largely driven by the consequences of the Buhlmann algorithm's treatment of helium (helium gives you more deco, the position you've taken) and some more progressive schools of thought that helium is a relatively good thing in terms of reducing overall narcosis, work of breathing, and that it has some benefits for dives in the 100-130 recreational range. I think the differing opinions on this subject have been helpful in highlighting some of the points to consider when approaching a class on this subject.

[sheahanmcculla]

Sheahan there were other suggestions for you buried in this thread. I think for you step 1 would be get the IP checked on your reg to make sure it's not too low. Step 2 would be to dive more, make sure that you're breathing is deep and even. See if these two take care of some of your narc issues. Step 3, do some moderately deep dives, take a gas management class so you know what you're doing gas plan wise going deep. Track your RMV. If it going through the roof on the deeper dives that (to me) points to anxiety and the corresponding increased breathing rate that's not going to help your narc.

Then start thinking about the other stuff.

Plus, as someone whose seen the boat at Mukilteo, I recommend going to EUP. There's an identical one there at about 40' that you can spend all day on with no narc at all. And there's more life on it too.

Jake

As I posted on this one we were deviating too much for this thread topic. If you want to go into detail lets start another thread with this and talk about molecular weight permeability and solubility. We are not helping the originator with their question. As Jake summed up and I mentioned earlier.

1) Check the IP of your regulator.
2) A shop can also run a mag test on it and measure the draw and on most good regs this can be adjusted.

Testing the IP will tell you a lot, almost always if the IP is good the Mag test will be good as well. I have seen several just serviced regs for different shops that had too low of IP pressures before. It is not a uncommon thing to happen. If you do not have the capability to do a IP test yourself "take it to a different shop than the one that serviced it and get it checked". I think a IP gage is a integral part of a took kit. I check mine all the time, and form time to time have to adjust it to get it back on track, they will vary a little. especially if you dive a great deal or you toss it in the closet and drag it out once ever 2-3 months to dive.

I myself for the past 30+ yrs of diving have service all my own equipment. It is my life support, it goes to the analogy of a pilot or a skydiver in my mind. You had better pack your own parachute or dam well trust the individual that is packing for you, you life is in their hands at that point. their are only a few out their that I would trust.

Your right, I totally forgot about the IP on the regulator! I will get that checked. I did practice the slower fuller breaths this weekend, and I will really focus on that from now on. I like the boats at Edmonds, and I’m sure there are tons more life on them, but I just think of the Muk one as a goal or achievement as I get better. That’s all no special reason. I’m not sure if there is an octo there anymore, that would be cool!

I will probably go in my LDS tonight and have them check out the Regulator. I will post the results to see what you guys think. Also are those mouthpieces that say "high flow" a joke or do they provide a smoother breath?

I'm pretty sure you can take Helitrox in a single tank setup, and I know you can take GUE Fundamentals and Rec Triox that way.

Thanks! less money to shell out.

[loanwolf]

We are not helping the originator with their question.

I'd disagree. There are some fundamental differences in people's attitudes towards helium, an old-school attitude largely driven by the consequences of the Buhlmann algorithm's treatment of helium (helium gives you more deco, the position you've taken) and some more progressive schools of thought that helium is a relatively good thing in terms of reducing overall narcosis, work of breathing, and that it has some benefits for dives in the 100-130 recreational range. I think the differing opinions on this subject have been helpful in highlighting some of the points to consider when approaching a class on this subject.

I am not disagreeing with you TM an HeO2 have benefits at recreational limits when used in moderation. Thus the statement of "more is not alway better" a generalized statement. I am not going to go into detail and do not see the need to go into theory on a thread started by a individual who is not trained to use either. All that is being done is putting out info that is over their head and beyond their understanding.

i just wanted to clarify because the jest of the conversation looked to be leading to, "if a little is good more will even be better".

Go to Decostop there are endless arguments on decompression theory. One thing to look, and please any of our commercial divers and I know their may be still a sat diver or two still on this board chime in. But lets be prudent and start another tread and chime in. As these can wind up in endless debates. No one in the world puts more time in the water than commercial divers do. No one in the world does more decompression than commercial divers do. What standards do they use?
I will agree they are not recreational standards. They are much higher standards and take more training and safety monitoring.

[vbcoachchris]

If you are interested in trying any of the gear out before you buy it, send me a PM. I can outfit you in the set up and then we can go for a dive.

BTW It may sound a little complicated at first, but recreational helium diving is quite simple. Remember how overwhelmed you felt in your OW class with all the new information. Trust me it is not complicated at all.

Scott

[spatman]

I am not going to go into detail and do not see the need to go into theory on a thread started by a individual who is not trained to use either. All that is being done is putting out info that is over their head and beyond their understanding.

there are others of us reading this thread that may benefit from further discussion. often times the realization that the info is over our heads can be the impetus to learn more.

[fmerkel]

Let me muck this thread up a little more by introducing a new concept, at least new for some people.

Dead space

No, not the space you end up dead because of a stupid Scuba accident.
Dead space is the gas that physiologically takes part in ventilation (air movement) but not respiration (actual gas exchange).

An extreme example-Let's say you have a lung vital capacity (amount you can take in and blow out maximally) of 5 liters. Now, get a really long garden hose that the internal capacity is also 5L. Plug your nose. Breath through the hose. You can ventilate (move air).....but you die after awhile because you cannot get rid of C02 build up or get in fresh O2 (respiration). The good stuff is WAY out at the end, the bad stuff is just cycling in the hose. That's dead space.

Our regs have dead space, essentially the primary's volume. It's pretty small but part of the package. Not much we can do about it.
Our bodies have dead space, all the tubing conducting air down to the alveolus. Not much we can do about it either.

What's the point?
Back to a different example. Now lets cut that hose to 2L and breath through it. Breath normally at first. Those breaths will be ~ .5-.8L. C02 will build up and you'll feel crappy and air hungry so you'll increase both depth and rate of respiration. If you merely increase rate you will ventilate a lot more > but you still die.
If you increase Volume to more than the 2L dead space you start getting some fresh air.

Anxiety tends to increase rate more than it does volume. In normal circumstances this reaction is quite effective and works. Scuba is not normal.

Increased rate of course means each breath must be faster. Air needs to move faster. In deeper scuba the air is denser and doesn't move so well.
Increased rate/speed means the air molecules must traverse a pretty complicated pathway faster. This leads to increased turbulent flow of the gas. This is less efficient and increases the relative dead space due to inefficiency. Slower breathing creates more laminar (smoother) flow and the gas flows better. The smaller the tube, the more important this becomes. The deeper the denser that gas, the more important this becomes.

If you take a lot of short shallow breaths at depth you are ineffectively ventilating gas thorough your own physiological dead space.

We can't do much about the dead space. If you recognize that anxiety is an issue, and merely increasing the rate of respiration at depth is not dealing effectively with the whole problem due to turbulent flow and increased gas density. You need to slow down, breathe deeply, let those gases move around in the most effective way they can. You may not even FEEL anxious. People often don't recognize it. You have a lot going on and this task loading interferes with full awareness.

Newbies almost never have good bottom times, they suck up their air. Most of this is high respiratory rates and anxiety. They often do not recognize or admit to being anxious. More often they only think they are excited. After a few 100 dives you are WAY better. Is it because you tolerate CO2 build up better? No way-the body HATES that. You have learned HOW to breathe MORE effectively using the SAME amount of air (same tank on your back-right?) so that the seemingly DECREASED ventilation is ACTUALLY BETTER respiration. Depth just compounds this problem and exaggerates the issues. Throwing narcosis into the mix REALLY mucks up the works.

Practice nice, deep, calm breathing at shallow depths. Get really nice and comfortable. Then slooowwwwllllyyyy move that down to more depth. Pay attention to the breathing. Pay attention to the anxiety state. Move the focus inward. By 100 dives you shouldn't need to focus as much energy outward to deal with buoyancy, visibility, location, etc. After awhile this kind of breathing becomes automatic. I find myself doing it in the tropical tank in the Aquarium and I'm only 5-7 feet deep.

Yeah, get that IP checked. If your reg does not perform properly the WOB (work of breathing) goes up and this can be a real problem. As you increase RATE the problem is even worse.

BTW-what reg (sorry if I over looked that)? A few aren't so hot once you start going deep but work fine at general recreational depths.

Fritz

[sheahanmcculla]

BTW-what reg (sorry if I over looked that)? A few aren't so hot once you start going deep but work fine at general recreational depths.

Fritz

Aqualung Titan LX

[CaptnJack]

BTW-what reg (sorry if I over looked that)? A few aren't so hot once you start going deep but work fine at general recreational depths.

Fritz

Aqualung Titan LX

It should be more than fine to 100ft. Has it been serviced recently? FYI, even new it may be mistuned.

I have an unbalanced piston with an unbalanced 2nd stage ("worse" than your balanced 1st with balanced 2nd). You'd think from all the marketing hype I'd die taking such a thing to 100ft, but I'm still here and quite comfy with it.

[Nwbrewer]

BTW-what reg (sorry if I over looked that)? A few aren't so hot once you start going deep but work fine at general recreational depths.

Fritz

Aqualung Titan LX

It should be more than fine to 100ft. Has it been serviced recently? FYI, even new it may be mistuned.

I have an unbalanced piston with an unbalanced 2nd stage ("worse" than your balanced 1st with balanced 2nd). You'd think from all the marketing hype I'd die taking such a thing to 100ft, but I'm still here and quite comfy with it.

I have a US divers Prodiver (I think unbalanced everything) that has no problem delivering enough gas at 100', even kicking into the current. I should be dead for sure. :naka:

[airsix]

I have a US divers Prodiver (I think unbalanced everything) that has no problem delivering enough gas at 100', even kicking into the current. I should be dead for sure. :naka:

Jake, that regulator was one of the very first sport regulators to ever pass the US Navy inhalation effort performance test. I still proudly wear the 2nd-stage as my bungied backup (for now).

AQUALUNG (US
DIVERS) PRO DIVER
P/N 1021-95
AUTHORIZED TO 190 FSW AND 38
DEGREES FAHRENHEIT WATER
AND WARMER. NO LONGER
MANUFACTURED, BUT
AUTHORIZED FOR CONTINUED
USE AND MANUFACTURER WILL
CONTINUE TO SUPPORT.

[Nwbrewer]

I know, and it has the same basic guts at the Titan. Compare the looks of the Titan to the prodiver too. Notice anything? I wish I could convert the 1st to DIN, I'd still be using it too.

I still wear mine as the backup too. I got a XTX50 as my primary now, but it did 3years of duty as my primary reg. I'm breathing off it in my avatar.

[LCF]

First off, Mr. Merkel, that's a beautiful little essay on respiratory physics and the advantages of slow, deep breathing, and thank you.

Second, I just wanted to say that I have an Aqualung Titan regulator which has been below 100 feet on a fair number of occasions, and has breathed very well. It's a good reg.

[fmerkel]

OK-you got enough support for your reg. Just making sure. My wife started out with a Sherwood Oasis. For recreation, it's a fine reg. Take it deep and work hard, it's a little thin. Not necessarily dangerous, just doesn't 'put out'.

So, the likely problem is.....you. That's not supposed to be an indictment or condemnation in any way. It's a recognition that you may have a physiology that is not terribly tolerant of depth issues or is merely a realization that you have some more work to do to become comfortable with those kind of depths.

Ultimately it's a personal issue. I'm coming up on 700 dives. I still have yet to break the 130 foot 'recreational' level and I got as close to that on my 10th dive as I ever have. Courageous? No--------uninformed and still ignorant.
Really, there's mostly not a lot to look at down there with rare exception (Diamond Knot---sigh!)

Fritz

[loanwolf]

Really, there's mostly not a lot to look at down there with rare exception (Diamond Knot---sigh!)

Fritz

You are wrong on that. you do not see the best stuff till you get below 150'. Take Davidson Wall bellow 150 feet is were the sponges are and the critters that are tiny above are much larger below. Also in certain area, Mostly in Canada you can get soft corals growing, "yes in cold water". Also the vis is almost always much better. the last time i dove Davidson once we got below 120' we had close to 100' of vis. Matt and Patric can contest to that. 80' and up vis was 20'-30'.

[LCF]

I have to admit that, if a year ago, you had asked me whether there was anything locally worth doing a tech dive to see, I would have said no. I am not a wreck person. I dive for sea life, and most of it is shallow. But I'm learning that there are some fascinating things founds at the edges of the recreational dive spectrum, like the cloud sponges in BC, and there are some sites that are fabulous that only begin in the depths, like Waterman's Wall. Slowly, I'm beginning to believe that there are enough of these dives to make some staged decompression training worthwhile. I would not have thought so, just a little while ago.

[loanwolf]

That is the reason I would not bother with recreational trimix class. Just go all the way. Once you start to dive deep then you will really be able to see some beautiful sites. Our sponge forests are to me much more beautiful than a coral reef is in warm water.

[CaptnJack]

That is the reason I would not bother with recreational trimix class. Just go all the way. Once you start to dive deep then you will really be able to see some beautiful sites. Our sponge forests are to me much more beautiful than a coral reef is in warm water.

For someone with only a hundred or so dives that would be rather foolish. There are scads of interesting sites to see without the added expense, complexity and risk of decompression. For instance, Davidson Rock is a lovely site <100ft.

[loanwolf]

That is the reason I would not bother with recreational trimix class. Just go all the way. Once you start to dive deep then you will really be able to see some beautiful sites. Our sponge forests are to me much more beautiful than a coral reef is in warm water.

For someone with only a hundred or so dives that would be rather foolish. There are scads of interesting sites to see without the added expense, complexity and risk of decompression. For instance, Davidson Rock is a lovely site <100ft.

If someone is a competent diver with 100 logged dives or more meets the prerequisites for I believe all the technical agency's to take Adv Nitrox, Deco, then Normoxic Trimix. Not to mention you will pick up many more dives and much more experience during the time frame of of the training.

[Sounder]

Meeting the minimum prerequisites doesn't mean someone is ready. Some divers are rockstars after 100 dives and others are train wrecks, all with the same number of dives.

[vbcoachchris]

To enter NAUI Helitrox: You should have NAUI Master Diver level skills

You must pass a screening evaluation to determine your readiness to enter Helitrox

You need to:

Demonstrate comfort in the NTEC (Hogarthian) configuration
Demonstrate a mastery of buoyancy and trim
Demonstrate Global Awareness
Demonstrate non silting propulsion techniques
Demonstrate mastery of basic underwater skills (Gas sharing, mask clearing, regulator skills, etc.)

NAUI Intro to tech (which can be done in singles) is a non certification course that helps you, either prepare for or determine your readiness for, upper level NAUI course such as Helitrox.

As Sounder said I have had students come to me with 75 dives who are more than ready to enter Helitrox and others who have 100’s of dive and are not even close.

Sometimes you just "don't know" what you "don't know"

I always offer FREE screening dives. Just send me a PM if you are curious where your diving skills are in relation to a recreational helium class and we will go diving.

Scott Christopher
NAUI Technical Course Director
www.soundaquatics.com
(425) 241-1113

[loanwolf]

Meeting the minimum prerequisites doesn't mean someone is ready. Some divers are rockstars after 100 dives and others are train wrecks, all with the same number of dives.

yes as i stated a "competent diver". and i agree not all divers will be ready at 100 dives. That also goes back to the quality of Instructors they have had in the past. Garbage in Garbage out. I have seen several divers go form open water to trimix in in as little as 6 months. These were very dedicated folks who had the drive, time, and excellent instructors to get them though it.

Naui Tech and PADI DSAT are both fairly new programs, and just like their open water programs has things broken into far more classes to get to the same level as as the full Tech Agency's do. That is their marketing strategy. They are good programs but will take a considerable more amount of time and money to get though to the same level.