If you are a new diver, please read this

[Puffer Fish]

The training agency problem is that people are afraid of math and that teaching gas management will take too big a slice out of the 20 hours allotted for the course. I think it borders on the criminal.

Thal, part of the problem with the issue is a lot of very needless complexity.

Science people will have difficulty remembering the terms because they are being used wrong, and non-science people will have difficulty because there are so many.

All one should address is:

Air usage -cubic ft/minute or the metric equivalent (which is V/T, but who cares)

How PSI relates to usage (for the tanks they are using - with a disclaimer for different size tanks)

A couple of graphics (a large tank, with markings on the side, for example) and one can cover all the major points in under 30 minutes, at the same time covering a couple of other topics.

 

[Thalassamania]

Rather critical is the change in air usage with respect to depth, don't you think? I find all the gas laws easy to teach, a half hour from first principles is all it really takes for the whole shootin' match, not just the Reader's Digest version.

 

[mselenaous]

Not being able to get positive at the surface might have been because she didn't know how to ditch weight.

I suggest that sufficient gas management can be taught at the Open Water level under any agency standards. It does not have to involve excessive math. A simple mention that many people recommend starting the ascent with one-third of their air remaining could go a long way.

Sadly, how many people are more afraid of losing $100 in lead than their lives?

Sad event. My prayers to the family. Thanks for the post and the links to great articles. Like knotical mentioned, I try to introduce gas management concepts to students (despite the deer-caught-in-the-headlights stare) but feel hindered by time constraints set by LDSs (and local marketplace pricewars). Agency standards are yet another issue. I keep incidents like these in the back of mind with each class of students as I repeatedly drill safety at them.

 

[dumpsterDiver]

Very Sad. I wonder if an air integrated computer that did the air management calculation and started to beep to signal ascend would help?

Maybe that would be an easier sell than requiring gas planning calculations to be learned in an open water course?

How deep were they diving?

 

[eponym]

Thanks for starting this discussion, L.

This incident must have been hard on you and the many good divers up there. It was just last Summer (if memory serves) that two "new" (didn't dive for a year post-cert) divers in San Diego went too deep and ran OOA with terrible consequences.

It's absurd to tell an instructor he/she may not talk about gas planning. There can be no debate on this. Courses talk and drill and talk and drill how to deal with OOA, but don't spend any time on how to create a dive plan that makes OOA vanishingly unlikely.

I am fortunate in that my shop and agency don't mind what I add to the course. And for those who think "oh, no, math" it doesn't have to be that way. What's wrong with simple rules of thumb? "Never go deeper than the number of cubic feet of gas you take with you" is one such. Knotical already referred to the rule of thirds.

-Bryan

 

[mikemill]

They didn't watch their gauges. But if someone had taught them how fast their gas would disappear at depth, maybe they would have been more vigilant.

Where did you get the information that they didn't watch their gauges and weren't taught that gas consumption increases at depth?

From the information given we don't know what caused them to run out of air. For all we know they could have had a solid gas plan and then just failed to follow it.

 

[LeadTurn_SD]

Incredibly sad. Thanks for posting this TSandM.

I find it really disturbing that your husband was told he could not teach gas management at the OW level. But I bet he'll find a way to do it anyway ..... .....

Best wishes.

 

[Gombessa]

Very Sad. I wonder if an air integrated computer that did the air management calculation and started to beep to signal ascend would help?

Maybe that would be an easier sell than requiring gas planning calculations to be learned in an open water course?

In this particular case, that may have gotten them to the surface. But then again, so would the scuba police or a 500# lift bag attached to their BC that auto-inflates if they're below 30ft when they hit 500psi . At what point do you mandate that every diver own a certain type of computer, and every shop have such a computer on every regulator in their rental fleet? Instead of teaching people to wait for the computer beep and follow further directions, a stronger emphasis on the importance of gas planning and gas management in basic open water class could have made them more aware and safer divers under any circumstance.

How deep were they diving?

I heard it was about 100ft depth.

 

[themagni]

Sadly, how many people are more afraid of losing $100 in lead than their lives?

My OW instructor told me that if I ever start to think about ditching the lead, then ditch the lead. I could then go find him at any point in the future and say, "Brian, I ditched my lead," and he would buy me new lead.

Very Sad. I wonder if an air integrated computer that did the air management calculation and started to beep to signal ascend would help?

Never trust a computer with your life. I say this an a EE who has worked with globally-deployed life-critical systems. It's like those old reserve valves - it'll work fine for years until one day when it fails at depth. Be prepared and be ready to whip out an analog gauge.

I did note that the effects of cold have not been discussed in the gas calculations. Is the drop in temperature (and thus the increase in gas used per breath) not big enough to worry about unless you're cutting it razor thin anyway? It's late and I'm tired and I can't remember if the calculations are supposed to be in Kelvin. Oh, wait, yes, of course it would be Kelvin, so a change from 277K to 297K would be negligible. Never mind.

 

[Thalassamania]

My OW instructor told me that if I ever start to think about ditching the lead, then ditch the lead. I could then go find him at any point in the future and say, "Brian, I ditched my lead," and he would buy me new lead.

I'm glad you mention that, I've always had that same policy, and I've only had to pay off twice. Well worth it.