Will Air Integration in dive computers replace the SPG?

[The Chairman]

Well, imagine that. I've dove three different gasses on my PDCs using transmitters. It's not that hard. You have to change gasses on any PDC when you're diving multiple gasses, whether they have transmitters of not. Surely you can't be that ignorant to not realize it's the same thing.

However, when I cave, I usually only put transmitters on my two side tanks, gauge the stage and gauge the oxygen. Stage and side tanks have the same mix. That works well for me. That will keep me down for an hour fortyfive or better in Ginnie. I start to get cold after that long in spring water. I might have to start using thermal protection when my dives get longer. When you're built like a manatee, you get to dive like one, but I'm reaching my limit.

Now, for the ignorant comments about DCS and Obesity made by @DevonDiver . Again, we've been FIGJAMmed. There doesn't seem to be any correlation between obesity and increased diver deaths. From DAN's 2015 Annual Diving Report. <= Don't take my word for it. Please click the link to be able to read the whole report like I did. This is the line that interested me.

This prevalence of obesity among scuba fatalities concords with that found in the wider US population, at 35%

I'm sure that Andy thinks he knows more than DAN, but according to their report, they can't make a causal connection. That's what "concords" means Andy. But, it's apparent that Andy is just looking for another way he can show how much better he is than anyone else. Rather than do the research, he speculates wildly and expects us to accept this BS over Science. Mind you, if you can lose weight, I'm sure it will be great for you. I swim laps most every day and while I'm not the fastest, I do OK. I'm just under a half mile right now and it feels good. My resting pulse is @46, my blood pressure is kinda low and I feel great about my diving. I'm not about to stop diving because some FIGJAM wants to bully people on the interwebs. I would love to lose weight but at least I don't go around telling people they're gonna die to boost my ego. FWIW, I've never seen a skinny marine mammal, have you? There's a lot of fat bigotry in this world and the FIGJAMmers lead the pack.

Again, I've gone 47 years without getting bent. I've been hit by a manatee. I've pulled a shoulder muscle on a wreck dive, I've bloodied my fingers pulling through caves, I've had a DAMNsel fish tear my ear and I've even been poisoned by CO. But, I've never suffered DCS. That's no accident. I dive within my limits and don't try to push them.

 

[The Chairman]

Never "blew-out" a face plate, seen a stuck pointer, catastrophic leak or other loss of function with an analog SPG;

Given your number of dives, I'm surprised at this comment. I've seen at least two "blow outs", one with minor injuries, but it's been at least a decade since the last one. I've seen lots of hose failures, including one that left a scar on the diver's face. I've seen a number of stuck/unreadable gauges. Two of those lead to an OOA on the diver. I've gone through half a dozen spool valves on a single day at Peacock springs. I buy 003 O-rings by the hundred and spools by the dozen now. I've seen several entanglements on gauges too. You've been very, very lucky or you need to work on situational awareness. I've one PDC that couldn't sync and had it replaced and one transmitter as well. None of these failed during the dive and if they did, it would have been the same thing as if my brass and glass SPG had failed. I would have called the dive. I have not called a dive ever due to this happening.

 

[lowviz]

At least I'm consistent. I absolutely detest automatic transmissions, and on a couple of occasions was filled with a savage delight when, in remote destinations, my compatriots at the airport car rental counter were reduced almost to tears because they couldn't drive a standard shift and that was all that was available.

Convenience? Inept shiftless indolence is a better descriptor.

Has AI become your Thermopylae?

Is this where you abandon being a Renaissance man? Let it go, let WAI fail or let WAI succeed under its own merit. Why do you care?

Marvel at how it unfolds, it is always so interesting to see how reality treats one's own predictions...

BTW, I used to have a 260 V8 with a 5 speed during the gas crisis. Now have a computer driven Envoy. Beast won't die. Looking for another scuba SUV on a real truck body. NSL...

 

[agilis]

Has AI become your Thermopylae?

Is this where you abandon being a Renaissance man? Let it go, let WAI fail or let WAI succeed under its own merit. Why do you care?

Marvel at how it unfolds, it is always so interesting to see how reality treats one's own predictions...

BTW, I used to have a 260 V8 with a 5 speed during the gas crisis. Now have a computer driven Envoy. Beast won't die. Looking for another scuba SUV on a real truck body. NSL...

A couple of ativan (tinnitus) and I get carried away. You are absolutely correct. Sometimes I argue for the fun of it, not cognizant of how serious people can be about these silly topics.. a tempest in a teapot.

 

[kelemvor]

I tell you what feels pretty sweet. A dive in warm water with a little al80, shorts (or a skin), a primary hose, an air2 hose, aluminum bp/w and light fins. It is just super enjoyable. Only two hoses on your first stage is quite a liberating feel. Sometimes just having less crap to deal with is its own reward. Actually, now that my sac is hanging lower I have been seriously considering switching to an al40 with this setup for dives like blue heron bridge.

When I was regularly diving at the aquarium I used this config. It was quite pleasant

 

[lowviz]

... I argue for the fun of it, not cognizant of how serious people can be about these silly topics.. ...

But that is the fun of all this, no?

Suggestion: Don't worry how seriously others take this. This **** is seen and interpreted by everyone from the criminally insane to the next Gauss.

 

[DevonDiver]

Oh...I think I hit a nerve....and exposed a very weak character.

"The main advantage of obesity in divers is the tendency for adipose tissue to be a good energy source and an excellent insulator.8,10 In comparison with the overwhelming risks to obese divers, however, this advantage fades into insignificance."
Obesity and Diving, Diving and Hyperbaric Medicine Volume 36 No. 3 September 2006 145 ,Gisele ML Mouret

I said "known DCI pre-disposing factor".

Not having "conclusive evidence" is not a disproof of a long and widely-held theory. It is simply a recognition that insufficient evidence has been obtained to prove it scientifically. A very great many things are "not conclusive" about DCI.

Incidentally... the European Union (and British HSE) have this year introduced mandatory BMI testing for scuba instructors. Pete wouldn't be allowed to teach scuba in Europe....and I wonder if he'd even be allowed to dive in Australia...

"In Australia, dive medicals preclude many obese people from diving, but for U.S. divers, the topic often doesn’t come up during their annual medical exam"
Why Divers Die, Part II - 'The Heavy Load of Obesity', Undercurrent Magazine 2007

I see that crying 'FIGJAM' is just a denial mechanism for whenever Pete gets faced with a fact that he cannot bear to face. Or doesn't want to look sub-standard in front of his friends..

We can debate all we want, but I think it's incredibly disingenuous for a qualified scuba instructor to post such misleading health and safety information on a 'basic' public internet forum. To put your own personal insecurities before the good and safety of other divers is deplorable. It is reprehensible.It is repugnant.

For those novice divers reading this... there is not one single scuba manual or textbook, by any diving agency that does not list obesity as a DCI predisposing factor. In addition, there is a plethora... a blizzard... of medical and scientific papers that name obesity as a factor in DCI cases. I've quote a quick selection below.... just Google and see for yourself.

As for the DAN 2015 Incident Report... well, that's a report from 2015. It changes every year. Here's the report from 2004:...

"Obesity has long been considered a risk factor for decompression sickness, but the Divers Alert Network (DAN) also considers it a top reason for dive fatalities. In its report of U.S. injuries and fatalities in 2004, DAN found that 45 percent of the dead divers had a body mass index (BMI) of 30 or above, classifying them as obese. That’s a much higher proportion than the one-third of the U.S. population considered obese, suggesting that excess weight and poor physical conditioning are risk factors for many divers, both novices and pros."
Why Divers Die, Part II - 'The Heavy Load of Obesity', Undercurrent Magazine 2007

"US Navy divers with the highest quartile skin fold thickness (20% overweight) have been reported to have an increased risk of developing DCS.6,12 Those 25% or more overweight have been estimated to have a tenfold increased risk of developing DCS."
Obesity and diving, Diving and Hyperbaric Medicine Volume 36 No. 3 September 2006 145 ,Gisele ML Mouret

"Dive computers are increasingly relied upon by recreational divers. These dive computers are programmed with dive tables that are calculated for the average-sized individual and do not take into consideration obese divers.2,9,13 http://archive.rubicon-foundation.org 146 Diving and Hyperbaric Medicine Volume 36 No. 3 September 2006 Understandably, therefore, the use of dive tables by obese divers is also increasing their risk of developing DCS."
Obesity and diving, Diving and Hyperbaric Medicine Volume 36 No. 3 September 2006 145 ,Gisele ML Mouret

"Obesity has long been accepted as one of the many risk factors for developing decompression sickness (DCS) when diving. Whilst body fat is a great heat insulator, there are a number of disadvantages to an obese person diving. These disadvantages range from the physical restriction of wetsuits, to concurrent medical pathologies and the higher demands on the cardiovascular and pulmonary systems whilst swimming. The high solubility of nitrogen in lipids and fats results in 5.4 times as much storage of nitrogen in fat as muscle tissue. This increases supersaturation of fat with nitrogen and significantly increases the risk of developing DCS. Whereas, historically, dive medicals precluded obese people from diving, a review of the literature would suggest that a sensible approach to diving and the medical examination can minimise risks of DCS to the obese patient."
Obesity and diving, Diving and Hyperbaric Medicine Volume 36 No. 3 September 2006 145 ,Gisele ML Mouret

 

[DevonDiver]

"While body fat is a great insulator, that advantage is outweighed by the higher demands made on an obese person’s cardiovascular and pulmonary systems while swimming. Fatty tissue absorbs nitrogen at a rate five times faster than muscle does. But blood supply to fatty tissue is poor, causing a slow release of nitrogen and a greater risk of DCS. Combined with the greater effort needed for breathing, an obese diver’s heavy workload underwater increases use of oxygen and production of carbon dioxide."
Why Divers Die, Part II - 'The Heavy Load of Obesity', Undercurrent Magazine 2007

"Obesity & Scuba Diving
As fatty tissue absorbs more nitrogen than muscle and at a rate 5 times that of muscle tissue, obesity is a pre-disposing factor to decompression illness. Divers should try to maintain a fit and healthy lifestyle. This will not only help them avoid decompression illness but also enable them to enjoy the highly physical sport of scuba diving more."
London Diving Chamber

"From the standpoint of decompression, when one dives, nitrogen dissolves in all tissues of the body in proportion to the gas solubility and the blood flow to the tissue. As far as joint pain DCS is concerned (“the bends”), this arises primarily in tissues that contain water. However, nitrogen is very soluble in adipose (fat) tissue and, in overweight people, the fraction of this tissue in the body is high. In some cases, nitrogen loads can rise in adipose tissue and bubble formation can be extensive. While one would not develop pain DCS from this, these gas bubbles would be dumped into the venous system where they are carried to the heart and lungs. If the gas bubble loads to these organs is high, the lung capillaries become blocked, blood pressures rise in the pulmonary artery, and bubbles can pass through the lung vasculature (or a PFO, patent foramen ovale in the heart) and embolize the brain. We end up with a vein-to-artery "stroke" and neurological DCS."
Micheal Powell Phd, Decompression Scientist

"There are established risk factors that may predispose a diver to developing decompression sickness. Lack of physical fitness, increased age, obesity, dehydration, physical injury, alcohol use during diving, repetitive dives, and traveling to altitude to dive are some of the risk factors that may lead to higher incidences of DCS"

The Risks of Scuba Diving: A Focus on Decompression Illness, Hawaii J Med Public Health. 2014 Nov; 73(11 Suppl 2): 13–16.



"There is no question that the risks are increased for divers who are overweight (BMI greater than 30kg/m2)"
Obesity and Decompression Illness - ScubaDoc

"Obesity is one of the factors which increase the risk of decompression sickness. It has been suggested that any diver whose weight is more than 20% in excess of that derived from currently accepted tables should therefore be stopped from diving until he has lost enough weight."
Br J Ind Med 1984 May;41(2):275-8 Optimum weights for commercial divers.
- McCallum RI, Petrie A

"Obesity - An increase in adipose (fat) tissue leads to an increase in nitrogen loading in the body, since nitrogen is five times more soluble in fat tissue than muscle. Because fat can absorb more gas than muscle, it will take longer for the body to excrete it. It is assumed that there is a greater risk of decompression sickness."
Scottish Diving Medicine http://www.sdm.scot.nhs.uk/decompression_illness/

"Decompression sickness (DCS) is recognized as a multifactorial phenomenon depending on several individual factors, such as age, adiposity, and level of fitness. The detection of circulating venous bubbles is considered as a useful index for the safety of a decompression, because of the relationship between bubbles and DCS probability. The variables investigated were: age, weight, maximal oxygen uptake (VO2max) and percentage of body fat (%BF). The effects of age, weight and VO2max are more significant than the effect of %BF. "
Int J Sports Med 1999 Aug;20(6):410-4
Circulating venous bubbles in recreational diving: relationships with age, weight, maximal oxygen uptake and body fat percentage.
Carturan D, Boussuges A, Burnet H, Fondarai J, Vanuxem P, Gardette B
Faculte des Sciences du Sport, Luminy, Marseille, France

"185 U.S. Navy divers who did experience decompression sickness either before or after examination had significantly higher measures of skin fold thickness and weight when compared to those who remained free of decompression sickness. These findings suggest that obesity may be a contributory factor to the occurrence of decompression sickness".
Undersea Biomed Res 1984 Dec;11(4):395-406
Health risk factors for the development of decompression sickness among U.S. Navy divers. - Dembert ML, Jekel JF, Mooney LW

 

[DevonDiver]

I'd say Pete.... eat your words... but I think that'd be inappropriately humorous given that you, as a scuba instructor, just deliberately disinformed a novice-diver public forum on a significant diving safety issue.... all because you can't stand to leave one single board post I make without a harrassing remark... and because you feel the need to compensate online for being shoddy role-model to divers and are apparently in denial about your personal health issues.



From the same study that Pete selectively and misleadingly cited...

35% of scuba fatalities overall are obese people (BMI >=30)
46% of scuba fatalities overall are overweight people (BMI 25-29)
19% of scuba fatalities overall are normal or underweight people (BMI <=24.9)

That may agree (that's only what 'concord' means, Pete) with the demographics in the USA... a country suffering an obesity epidemic. But it's shocking to the rest of the world.

From what I see, a staggering 81% of overall scuba fatalities are comprised with people with BMI above 25 (overweight and above). That concurs with all the warnings, studies and texts; they might not be scientifically conclusive (yet), but the facts speak..

Just look at those blue and orange blocks folks...

I guess people don't need a computer with fat monitor to tell them that they're in a high risk percentile... that's what mirrors are useful for.... but integrating such tech might protect a few people trapped in willful denial..

 

[CuzzA]

Gasses, not tanks.

Never used two different gas mixes. Just practiced switching between two tanks at depth. More so to get some experience with slinging a tank and switching to it and played around with some different pony configurations.

That's nice. Can do a house-swap for my pad here on a Philippines' beach.

Sure, Philippines is on my list. You're in Subic Bay, right? Come hang at CuzzA Bay.