Trivia Question: Where Would You Be At 1/2 Ata?

[Doppler]

As an avid telemark skier as well as a diver, my guesses are that you cannot be looking for specific peaks since there are simply too many of them at 18,000 feet and above (the point at which atmospheric pressure is about 0.5 ATA

So how about Mountain Ranges? Let's see if we can keep it in the Americas... Canadian Rockies, Bugaboos, Alaska Coastal Range, Chugach Mountains, the Cordillera Blanca, Cordillera Huayhuash, (both in the Andes and each with more than a dozen peaks above 18,000 feet... great skiing too), one more.... OK the Selkirk Range...

Do I win!!!

 

[Doppler]

OK so at 18,000 feet, atmospheric pressure has dropped to about half of what it is at sea level... so what would your depth guage show if you dove to 34 feet in a pool up there?

What would the MOD of an EAN50 be at that altitude?

Regards

Doppler

 

[tankajava]

I'd be at Peterson Field, Colorado Springs in the altitude chamber requalifying for my flight physical.

Rapid decompression from 15,000 feet and up is pretty cool. Anoxia is a cheap high providing the chamber tenders are on the ball.......

 

[ScottyK]

Doppler once bubbled...
OK so at 18,000 feet, atmospheric pressure has dropped to about half of what it is at sea level... so what would your depth guage show if you dove to 34 feet in a pool up there?

What would the MOD of an EAN50 be at that altitude?

Regards

Doppler

You'd have to have your guage adjusted to zero before you jumped in

Dive computers do that automatically when you turn them on. My instructions said something to the effect of "don't turn it on, then drive up the mountain".

Scott

 

[CincyBengalsFan]

Walter once bubbled...
18,000 ft altitude

The majority of the atmosphere is in the first 18,000 so I would guess .5 ATA would be closer to Everest or higher.

 

[XJae]

tankajava once bubbled...
I'd be at Peterson Field, Colorado Springs in the altitude chamber requalifying for my flight physical.

I was about to say in a hypobaric chamber.

So that's two. On a mountain and in a chamber.
There are a handful of lakes over 18k that you could be doing some shallow diving in.

 

[XJae]

ScottyK once bubbled...

Dive computers do that automatically when you turn them on. My instructions said something to the effect of "don't turn it on, then drive up the mountain".

Scott

Yeah, and don't turn it on on the runway before takeoff.
It'll think you're rapidly ascending.

 

[ScottyK]

LOL- That's all you'd need! These day's if your ascent rate alarm started beeping in your carry on, you'd probably trussed, gagged and carted off by the FBI in about five minutes flat.

I went to Boston and back yesterday. Had to take my shoes off both ways, and coming back they ran my cell phone and shoes through bomb detector

 

[tankajava]

Passenger airliners are pressurized to approx. 80% sea level so that leaves commercial aircraft out.....

This is getting interesting. Good question, DT-Scuba.

 

[Walter]

"The majority of the atmosphere is in the first 18,000 so I would guess .5 ATA would be closer to Everest or higher."

Your guess is wrong. 18,000 ft is correct.

"OK so at 18,000 feet, atmospheric pressure has dropped to about half of what it is at sea level... so what would your depth guage show if you dove to 34 feet in a pool up there?"

First, from the NOAA manual, 4-26:

"DIVING AT ALTITUDES ABOVE 10,000 FEET IMPOSES SERIOUS STRESS ON THE BODY AND IS STRONGLY DISCOURAGED"

Assuming you ignored the above warning or sent the gauge down with a camera, you'd find the gauge would read 16.96 feet shallower than your actual depth. In this case, it would read 17 ft.

"What would the MOD of an EAN50 be at that altitude?"

The MOD for EAN 50 is 59.4 at 1.4 atm (72.6 at 1.6 for emergencies only). You could actually dive 16.96 feet deeper (76.36 at 1.4 or 89.56 at 1.6) without exceeding the MOD. Keep in mind, you have totally ignored Sea Level Equivalent Depth. For decompression purposes, a dive to 80 ft at 10,000 ft (.688 ata) is equivalent to a dive to 120 ft at sea level. You have also ignored warnings about diving at altitudes over 10,000 feet.