Difference between MB levels and Gradient Factors

[ChrisDee]

Why are we letting this guy troll us?

Again, you have nothing to contibute other than hemoraging advice about a particular dive computer that you freely admit you "have never seen." Again and again you provide misinformation and intentionally omitting information to support your faulty views about a peice of equipment, you "do not own." And again you deflect from the fact that you give , intentionally, incorrect information about a computer you have never used.

And your retort to cover up your inepness and conduct is to lable others as Trolls and threaten others with "reporting them" in your attempt to silence your agenda?

All anyone here wants is accurate and truthfull information about a competetors diving computer. Is that too much too ask for?

It is apprent that you are doing everything you can to mislead and misinform readers, to hold a very popular device with literirally closly to a hundered thousand in use, very popular with many contries militarys hostage to your intentianl misinformation. You do not get to slander and mislead based upon your say so. You do not get to threaten others in your attempt to cover up your actions. And you do not get to use raceism to further your agenda.

It is painfully apparent that this ScubaBoard is selecting who and what gets deleted. Which is a terrible shame that so many here do not realize is happening. The FACT that so many freely comment on a product that they do not own, have never used, and clearly haven't read the manual is frankley astounding.


The fact that anyone who actually owns this unit is being censored, minimized and threatened is NOT being a troll, it is pointing out systemic issues with a few people with agendas who will use any means whatsoever to bully, threaten, and minimize anyuone trying to be objective, factual, and accurate.

The G2 is a fine peice of Kit. And apparently the United States Navy agrees.

 

[ChrisDee]

On your G2 you must set you MB level, respiratory rate sensitivity, heart rate response, body temperature response. Do any of these variables have publicly available data to support the settings?

Yes they do. The same source and information that the other manufacutrer has.

 

[ChrisDee]

For some reason, the site where I published my article on this topic a few years ago is not working. Here is a link to the ScubaBoard thread I started after I published it. It contains a link to the article.

Evolving Thoughts on Deep Decompression Stops

A few months ago I met with a couple former tech students for a cave dive, and one of them told me with amusement of his dive the day before. He had randomly joined a group that included a technical instructor, and when that instructor learned that he used a GF Low of 50, he gave him a very...

scubaboard.com

It references all the known published research related to the topic at the time. If I missed any, let me know. If you have any relevant articles published after, let me know as well. I know David Doolette published an article on gradient factors after that, but he referenced my article and praised it, so you won't get anything different from him.

The question at hand is about GUE and efficency V. MB settings and PDIS settings on the G2.

Once again you deflect, and then start accusing others of something you think will garner some kind of public support in liew of actually answering.

You seem to be promoting "efficency" in liew of Micro Bubble supression, or something like that. Efficency, for those that actually know what they are speaking about has its place AS DOES Bubble surpression, they are not mutually exclusive, except to those that seem to be promoting one brand of equipment over another. The issue with you is the fact that you can not support your comments about how longer deeper dives "cause harm" in comparision with "efficency." I await this research which you so conviently seem to have misplaced.

You dive deeper, longer, you naturally will have longer decompression schedules. Somehow you have turned this fact into a debatable point. More than a few of us take exception to your unsupported comments.

 

[ChrisDee]

And?

The rate of ascent is the rate that the diver ascends, it matters not what some computer says you should ascend at, it only matters what rate you actually ascend at. There’s many reasons to do a slow ascent from depth, not least congestion on the shot line.

I want, no need a computer I can trust. Bulhmann works. It’s kept me from DCS over many hundreds of decompression dives (I use 50:80). I don’t trust other algorithms.

When I am at depth and I mean over 100M, I frequently ascend fast at those deeper depths. It is more efficent to do so. I am frequently ascending far in excess of 40' / Min.

I have to trust my computers, they are in fact telling me something, and as I reach shallower depths the RATE changes. At these depths I implicitly trust my multiple computers, they make the dive possible.

When diving recreationally around 50M or so,...the rate is much more in alignment with accepted practice of 33' / Min. this changes to a crawl near the surface. This is the heart of variable rate ascents. Again I trust my G2 with this function because I have frequently no other reference.

So IMO I completly disagree with your opinion about what matters or not. Variable rate ascents are here to stay, they are safe, they are more efficent, they are at the heart of mb supression, and a host of other positives in diving.

YOu "trust" Bulhmann, well 99.999% of all dive computers use Bulhmann, Bulhmann is the heart of UWATEC products, they were the first they continue to be the worlds leader that

EVERY OTHER MANUFACTURER USES.

 

[tursiops]

Again, you have nothing to contibute other than hemoraging advice about a particular dive computer that you freely admit you "have never seen." Again and again you provide misinformation and intentionally omitting information to support your faulty views about a peice of equipment, you "do not own." And again you deflect from the fact that you give , intentionally, incorrect information about a computer you have never used.

And your retort to cover up your inepness and conduct is to lable others as Trolls and threaten others with "reporting them" in your attempt to silence your agenda?

All anyone here wants is accurate and truthfull information about a competetors diving computer. Is that too much too ask for?

It is apprent that you are doing everything you can to mislead and misinform readers, to hold a very popular device with literirally closly to a hundered thousand in use, very popular with many contries militarys hostage to your intentianl misinformation. You do not get to slander and mislead based upon your say so. You do not get to threaten others in your attempt to cover up your actions. And you do not get to use raceism to further your agenda.

It is painfully apparent that this ScubaBoard is selecting who and what gets deleted. Which is a terrible shame that so many here do not realize is happening. The FACT that so many freely comment on a product that they do not own, have never used, and clearly haven't read the manual is frankley astounding.


The fact that anyone who actually owns this unit is being censored, minimized and threatened is NOT being a troll, it is pointing out systemic issues with a few people with agendas who will use any means whatsoever to bully, threaten, and minimize anyuone trying to be objective, factual, and accurate.

The G2 is a fine peice of Kit. And apparently the United States Navy agrees.

Thank you for your thoughtful input.

 

[Belzelbub]

Big issue is with GF and Sur GF is yo have to do mental gymnastics to understand what computer is trying to tell you. With G2 yo set it, you set it according to your plan. It does what a computer is supposed to do, rather than trying to figure things out real time. BTW, many users of SurGF and GF style have reported that they find spend most time staring at coputer tyring to figure it out. This is not a positive.

What? What mental gymnastics? I'm not sure you understand GF and SurfGF as you seem to be equating them to the same thing. I'm trying to understand what could be so difficult to understand.

I'll start with GF. In essence, this is the conservatism setting for the DC. A little prior research into what GF Hi and GF Lo are and you can set to where you want it to be. Or, if not, you can just choose one of the defaults. They are usually labeled as High, Medium, Low Conservatism. That's pretty easy to figure out. Once it's set, those settings apply. The computer functions just as it would otherwise with the desired conservatism settings providing the boundaries for NDL or the Deco plan. I don't see how having GF set to one or the other has users "staring at their computer trying to figure it out."

SurfGF is an additional piece of information. I find it useful, so have added it to the main dive screen on both my computers. If a diver can't figure out what it means, then they don't need to use it. It's not that hard, so again I don't see how having SurfGF displayed leads to divers "staring at their computer trying to figure it out." It's simply additional information. The diver can decide what they want the max SurfGF number to be before they begin the final ascent. It's simply then an act of understanding if the number displayed is greater than or less than the number the diver decided on. If the diver can't identify if a number is larger or smaller than another number, they probably shouldn't be diving. They probably would also have difficulty with other tasks as well.

You like your G2. That's great. No need to make up nonsense about SurfGF and GF to validate your purchase.

 

[scubadada]

Yes they do. The same source and information that the other manufacutrer has.

Thanks, where can I read about Human Factor Diving?

I have read through the G2 manual several times. The link on page 17 of the manual regarding HR is not functional. The breathing factor has 25 steps from -12/least, to +12/most. I can't find how that setting changes the deco algorithm or what it is based on. The HR allows you to enter baseline and max HR. I can't find how that information is used to adjust the algorithm or what it is based on. Skin temperature can be turned on or off, again, I can't find how that information changes the deco algorithm or what it is based on.

I have an interest in decompression algorithms and have not been able to locate information regarding the use of HR, breathing, and skin temperature in the Buhlmann ZH-L8 or 16 ADT MB algorithms.

 

[L13]

You seem to be promoting "efficency" in liew of Micro Bubble supression, or something like that. Efficency, for those that actually know what they are speaking about has its place AS DOES Bubble surpression, they are not mutually exclusive, except to those that seem to be promoting one brand of equipment over another. The issue with you is the fact that you can not support your comments about how longer deeper dives "cause harm" in comparision with "efficency." I await this research which you so conviently seem to have misplaced.

Micro Bubble suppression ONLY MATTERS if it contributes to efficiency by reducing the probability of getting bent for a given investment in resources (time and gas).

Example:
I do a dive with a 10% risk of the bends if I ascent directly to the surface at normal ascent rates.

• Algorithm A tells me to do 1.2 hours of deco
• Algorithm B tells me to do 1.0 hours of deco

Which should I pick? The answer is: insufficient info. If I tell you that B focuses on micro bubble suppression, now which should I pick? Still insufficient info.

What you really need to know is the new risk of getting bent after the algorithm. This is where efficiency comes in. Since both algorithms have adjustable conservativeness, I set them each to a setting that recommends the same resource consumption (gas differences tend to be minimal, so focus on time). Then I look and see which has reduced the risk of getting bent the most. This is what the recent NEDU research did. The result is was that, for the same deco time, deep stops were less effective than no deep stops at reducing the chance of getting bent.

Reducing micro bubbles appears to reduce the chance of getting bent, but based on the latest research limiting the magnitude and time of supersaturation appears to reduce the chance of getting bent even more.

You dive deeper, longer, you naturally will have longer decompression schedules. Somehow you have turned this fact into a debatable point. More than a few of us take exception to your unsupported comments.

That is a gross misrepresentation of what he was saying. Everyone agrees that deeper longer dives need longer deco. The issue is that deco algorithms that include deep stops add deep time that must be decompressed with even more shallow time and still result in less reduction in the risk of getting bent. That concept is not unsupported, it is the main take away from the recent NEDU research. Anyone taking exception to it is taking exception to the best research available to date.

 

[dmaziuk]

What you really need to know is the new risk of getting bent after the algorithm.

Or at least you would, if you knew the old risk.

Which IIRC is mentioned in the DSAT report and possibly may be mentioned in Tauchmedizin but I don't read German. If anyone knows what it is for various flavours of RGBM or PZ+, I never heard them tell teh rest of us. Ditto for various GF settings on top of ZH-L16.

As it is, IRL this is mostly the matter of trust. You trust ZH-L16+GF85: good on yah. He trusts ADT+MB: good for him.

 

[scubadada]

Or at least you would, if you knew the old risk.

Which IIRC is mentioned in the DSAT report and possibly may be mentioned in Tauchmedizin but I don't read German. If anyone knows what it is for various flavours of RGBM or PZ+, I never heard them tell teh rest of us. Ditto for various GF settings on top of ZH-L16.

As it is, IRL this is mostly the matter of trust. You trust ZH-L16+GF85: good on yah. He trusts ADT+MB: good for him.

If you know your NDL, or a dive time less than the NDL, and depth (square profile only), you can look up your risk on the SAUL recreational dive planner for air or 32%. Less exposure, less risk.

SAUL Recreational Dive Planner | Modern Decompression

I made a few spreadsheets a couple of years ago that illustrates what mean. Shown are NDLs per algorithm and the associated probability of DCs. I found it interesting. The P(DCS) is in %. The corresponding rates are shown in the 3rd spreadsheet.