Article in March 2006 issue of Scuba Diving

mike gray a écrit :
>
> VK wrote:
> > mike gray wrote:
> >
> > Good grief... isnt life so much easier with "1 bar every 10m", as
> > opposed to "14.7psi every 33 ft"?
>
> No. I can figger out in my head that it's 29.4 psi every 66
> feet, but what the hell is it at 2 bar?
>
> This is America! Speak American!

Tell that to the NASA engeeners about Mars Climate Orbiter ...

Benoît, who use Metric system ...

mike gray a écrit :
>
> VK wrote:
> > mike gray wrote:
> >
> > Good grief... isnt life so much easier with "1 bar every 10m", as
> > opposed to "14.7psi every 33 ft"?
>
> No. I can figger out in my head that it's 29.4 psi every 66
> feet, but what the hell is it at 2 bar?
>
> This is America! Speak American!

Tell that to the NASA engeeners about Mars Climate Orbiter ...

Benoît, who use Metric system ...

mike gray a écrit :
>
> VK wrote:
> > mike gray wrote:
> >
> > Good grief... isnt life so much easier with "1 bar every 10m", as
> > opposed to "14.7psi every 33 ft"?
>
> No. I can figger out in my head that it's 29.4 psi every 66
> feet, but what the hell is it at 2 bar?
>
> This is America! Speak American!

Tell that to the NASA engeeners about Mars Climate Orbiter ...

Benoît, who use Metric system ...

bob crownfield wrote:
> the short fast ascent will not produce N2 effects,
> but rather pressure effects,like pnemothorax,
> Respiratory barotrauma, Air Embolism, Mediastinal Emphysema,

Again, I agree with the theoretical risk. I simply dont see people
coming up so fast from their safety stop that they risk barotrauma.
Even from 5m, you'd have to hurtle like mad for this to happen.

So possible - yes.
Likely - no.

For me, this falls in the category of "dont climb onto the boat with
your own tanks" or whatever... the theory is fine, but odds of anyone
staying within their NDLs on a single tank and pretzeling themselves
doing this are probably lower than the odds of being molested by an
amorous dolphin.

I guess my problem is not so much in the concept being pointed out - I
actually make it a point to tell my OW students to come up slowly in
the last 5m (used to be on the old PADI OW exams as well - not in the
newer editions, though) - but in the way it *appears* to have been
presented (keep in mind, I havent read the article - if it is balanced
piece, mea culpa and apologies).

Vandit

bob crownfield wrote:
> the short fast ascent will not produce N2 effects,
> but rather pressure effects,like pnemothorax,
> Respiratory barotrauma, Air Embolism, Mediastinal Emphysema,

Again, I agree with the theoretical risk. I simply dont see people
coming up so fast from their safety stop that they risk barotrauma.
Even from 5m, you'd have to hurtle like mad for this to happen.

So possible - yes.
Likely - no.

For me, this falls in the category of "dont climb onto the boat with
your own tanks" or whatever... the theory is fine, but odds of anyone
staying within their NDLs on a single tank and pretzeling themselves
doing this are probably lower than the odds of being molested by an
amorous dolphin.

I guess my problem is not so much in the concept being pointed out - I
actually make it a point to tell my OW students to come up slowly in
the last 5m (used to be on the old PADI OW exams as well - not in the
newer editions, though) - but in the way it *appears* to have been
presented (keep in mind, I havent read the article - if it is balanced
piece, mea culpa and apologies).

Vandit

bob crownfield wrote:
> the short fast ascent will not produce N2 effects,
> but rather pressure effects,like pnemothorax,
> Respiratory barotrauma, Air Embolism, Mediastinal Emphysema,

Again, I agree with the theoretical risk. I simply dont see people
coming up so fast from their safety stop that they risk barotrauma.
Even from 5m, you'd have to hurtle like mad for this to happen.

So possible - yes.
Likely - no.

For me, this falls in the category of "dont climb onto the boat with
your own tanks" or whatever... the theory is fine, but odds of anyone
staying within their NDLs on a single tank and pretzeling themselves
doing this are probably lower than the odds of being molested by an
amorous dolphin.

I guess my problem is not so much in the concept being pointed out - I
actually make it a point to tell my OW students to come up slowly in
the last 5m (used to be on the old PADI OW exams as well - not in the
newer editions, though) - but in the way it *appears* to have been
presented (keep in mind, I havent read the article - if it is balanced
piece, mea culpa and apologies).

Vandit

Thus spake "VK" <vandit.kalia@gmail.com> :

>
>mike gray wrote:
>> When you ascend from, say, 99 fsw to 66 fsw the pressure change
>> is from about 59 psi to about 44 psi, a one-quarter reduction
>> which will result in a 25% expansion of the air in yer lungs.
>>
>> But when you ascend from, say, 33 fsw to the surface the
>> pressure change is from about 29.4 psi to about 14.7 psi and the
>> halving of pressure will double the volume of air in yer lungs
>> in the same 33 feet of ascent.
>
>Good grief... isnt life so much easier with "1 bar every 10m", as
>opposed to "14.7psi every 33 ft"?

Hell, on 6th Street here in Austin it seems like there's a bar every
10 feet.

>
>Am sending an OW student down your way to Splashdown, btw. If someone
>is there, asking for you to learn more about DIR, blame me for that :)
>
>V.
--
dillon

I didn't climb to the top of the
food chain to become a vegetarian.

Thus spake "VK" <vandit.kalia@gmail.com> :

>
>mike gray wrote:
>> When you ascend from, say, 99 fsw to 66 fsw the pressure change
>> is from about 59 psi to about 44 psi, a one-quarter reduction
>> which will result in a 25% expansion of the air in yer lungs.
>>
>> But when you ascend from, say, 33 fsw to the surface the
>> pressure change is from about 29.4 psi to about 14.7 psi and the
>> halving of pressure will double the volume of air in yer lungs
>> in the same 33 feet of ascent.
>
>Good grief... isnt life so much easier with "1 bar every 10m", as
>opposed to "14.7psi every 33 ft"?

Hell, on 6th Street here in Austin it seems like there's a bar every
10 feet.

>
>Am sending an OW student down your way to Splashdown, btw. If someone
>is there, asking for you to learn more about DIR, blame me for that :)
>
>V.
--
dillon

I didn't climb to the top of the
food chain to become a vegetarian.

Thus spake "VK" <vandit.kalia@gmail.com> :

>
>mike gray wrote:
>> When you ascend from, say, 99 fsw to 66 fsw the pressure change
>> is from about 59 psi to about 44 psi, a one-quarter reduction
>> which will result in a 25% expansion of the air in yer lungs.
>>
>> But when you ascend from, say, 33 fsw to the surface the
>> pressure change is from about 29.4 psi to about 14.7 psi and the
>> halving of pressure will double the volume of air in yer lungs
>> in the same 33 feet of ascent.
>
>Good grief... isnt life so much easier with "1 bar every 10m", as
>opposed to "14.7psi every 33 ft"?

Hell, on 6th Street here in Austin it seems like there's a bar every
10 feet.

>
>Am sending an OW student down your way to Splashdown, btw. If someone
>is there, asking for you to learn more about DIR, blame me for that :)
>
>V.
--
dillon

I didn't climb to the top of the
food chain to become a vegetarian.

"Benoit T" <invalid@noos.fr> wrote in message
news:44578AA5.85037E1@noos.fr...
> mike gray a écrit :
> >
> > VK wrote:
> > > mike gray wrote:
> > >
> > > Good grief... isnt life so much easier with "1 bar every 10m", as
> > > opposed to "14.7psi every 33 ft"?
> >
> > No. I can figger out in my head that it's 29.4 psi every 66
> > feet, but what the hell is it at 2 bar?
> >
> > This is America! Speak American!
>
> Tell that to the NASA engeeners about Mars Climate Orbiter ...
>
> Benoît, who use Metric system ...

There were lots of other problems on that mission, besides just the units.
IEEE Spectrum had a nice article on it a few years back

Dennis