Lung overexpansion, please help

[Louwhale]

Hey there,

I have friends with a little pool, max depth is 4 feet. I'm considering introducing their kids to diving and want to make sure that environment is safe. I understand about not holding your breath, but I want to cover all bases just in case they don't. So the real question goes as follows: at what depth does lung overexpansion become a possibility?
Thanks.

 

[Max Speed]

4 feet. Seriously.

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[dumpsterDiver]

4 feet...

 

[chrpai]

PULMONARY BAROTRAUMA - Cyprus Federation of Under Water Activities

In this situation, to avoid over distension of his lungs, the diver must exhale 12 litres of air (measured on the surface) before or during his ascent. If he does not exhale this air, the expanding gas will distend his lungs, like a balloon, and even some normal lungs will rupture if they are distended more than 10%.

When near the surface, this 10% distension can be produced by an over-pressure of about 80mm Hg. - equivalent to the pressure difference between one metre depth (less than 4 ft.) and the surface, making pulmonary barotrauma a real possibility even for a scuba diver in a swimming pool. Divers have died from pulmonary barotrauma in shallow swimming pools

That said, I've taught boyle's law to my 8 and 10 year olds and when they were able to convince me that they understood the importance of keeping the airway open, I let them swim around with my AL40.

 

[fisheater]

That's 4 feet for adults.

For kids? It may be less!

Don't do it!

Even if nothing bad happens, injury-wise, what lesson are you teaching them when it comes to dive safety rules? Kids think they're immortal as it is. We adults need to be sure that we don't teach them to flaunt the safety rules.


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[TMHeimer]

I know I'm not simply answering the question and have been critical of others who don't and then put forth their views. But I'm curious as to how old these kids are. If they are not of age to take a Jr. Scuba course, why the rush? Why not just some snorkelling?

 

[Eff]

Mandatory disclaimer: I am not a certified instructor.

That being said...
In a couple pools near me; I've taken many kids diving in ~4 feet of water. Youngest was "8"
(Oldest was 63 )
At least a few of them that I know of have gone on to enroll in certification.

None of them took more than a minute or two of explaining before they understood the basic logic behind "never hold your breath."
If anything, the kids I dove with were better at following the rule than the adults. Not to mention that they were SUPER psyched afterwards and wanted to know all they could about the sport. Possible future divers and all...

To answer your question about lung over-expansion threshold; I've read literature that states ranges from 3-6 feet. The general consensus seems to be around 4 feet.
EDIT: Bear in mind, that is ascending with a FULL breath.

As for whether or not you should do it without having 16 lawyers on site, two waiting ambulances, and a bleacher full of PADI PRO instructors to coach everyone...


They'll be fine, and the experience will change lives.

 

[Louwhale]

The kids are 8 and 9, which makes them "bubble maker" age. I just checked the PADI website and it describes that the courses take place in "less than 6 feet", which makes me wonder about the 4 feet lung overexpansion risk mentioned above.

 

[dumpsterDiver]

The kids are 8 and 9, which makes them "bubble maker" age. I just checked the PADI website and it describes that the courses take place in "less than 6 feet", which makes me wonder about the 4 feet lung overexpansion risk mentioned above.

If you are so unsure about the most basic concepts of physics associated with diving, you probably shouldn't be teaching 8 yr old kids to dive..

my kid was diving to 60 feet when he was 9 (with me), but I knew what the hell I was doing..

 

[gekodivebali]

Why not find an instructor to take them in the pool?