HDTenEightyP/NetNews huggingface dataset:
From: s32905u@saha.hut.fi (Jouni Ilari Polkko)
Subject: Re: Human bodies explode in vacuum?
Organization: Helsinki University of Technology, Finland
Date: Sat, 21 Nov 1992 12:10:09 GMT

In article <14229@cis.rand.org> schutz@rand.ORG (Karl Schutz) writes:
>In article <1992Nov19.103112.3699@nntp.hut.fi>, s32905u@saha.hut.fi (Jouni Ilari Polkko) writes:

>> I have noticed in pressure chamber at 50 m (164ft) that breathing is 
>> heavier than in 1 AT pressure. However, I haven't noticed this during
>> my dives to 50-60 m region. Maybe this is due to additional stress and 
>> poor judgement becouse of narcosis in water diving, compared 
>> to just sitting in the chamber in air.

> Question: what's the difference between breathing air in a chamber under pressure
> and breathing air (via scuba I assume :-) ) at an equivalent depth in water? 
> Your body absorbs nitrogen due to elevated partial pressures (Henry's Law).  
> Isn't pressure is pressure is pressure, whether water or air, or whatever, 
> induced?  So, nitrogen (I assume) narcosis should be an equivalent problem in a
> chamber ... yes/no?

Maybe I was little inaccurate. Of course the effect is same in the chamber
as in the water. I just meant psychological difference to notice this. 
In the chamber, there is nothing else to do but to observe, so it is easier
to notice little things like this. In water, you have to consentrate to 
your task and surviving. Reason that I haven't noticed this effect while
diving is probably that I haven't payed enough attention to it. Also in
water, you can not say that is the increased breathing load due to regu-
lator or pressure itself. 

> -- 
> Karl F. Schutz
> PADI DM-50321

Jouni Polkko
CMAS P3 M1
Newsgroups: rec.scuba
From: dremsen@mbl.edu (David Remsen)
Subject: Re: Sharks: Search and destroy???  (listen up!)
Organization: Marine Biological Laboratory
Date: Fri, 20 Nov 92 18:15:02 GMT

In article <1992Nov20.034615.10362@reed.edu>, pbray@sloth.Reed.Edu (Peter Bray) writes:
> 

> 	Actually tiger sharks do pose a great threat to scuba divers. 

> 		Peter 

How many scuba divers are killed by tiger sharks in Hawaii where this hunt is
to take place?  How many people are killed by this species?  Once again, this
is an example of completely over-reacting to a fairly minor threat.   Why we
do we see these public efforts to wipe out a whole population based on such a
rare occurance by one or two individuals.  We certainly don't see any such efforts
made toward curbing homicides or vehicular deaths.  

>	 Actually tiger sharks are assumed to have a nil effect on  
> population dynamics in the food chain

I think it's ludicrous regardless of the role these predators play in the ecosystem. 
Where is the ethical justification for this?  When are we going to wise up/  This isn't
about managing a shark fin fishery or even a sport fishing industry.   It's not even
paranoia.  It's simply focusing on something controllable to avoid dealing with issues
that are more complex.  

I support any petition against this decision.

David Remsen
Newsgroups: rec.scuba
Date: Wed, 18 Nov 1992 16:19:44 -0500 
From: "Peter A. Simon" <ps3p+@andrew.cmu.edu>
Subject: horse collars

To the people in the UK who wrote to me about horse collar BCs and
inflation systems and did not get a reply:  Your mail bounced!!!

I want to thank all of you for your thoughtful and informative replies.

Peter
NAUI Inst. 1434
From: schutz@rand.ORG (Karl Schutz)
Newsgroups: rec.scuba
Subject: Re: Human bodies explode in vacuum?
Date: 20 Nov 92 00:00:21 GMT
Organization: The RAND Corporation, Santa Monica, California

In article <1992Nov19.103112.3699@nntp.hut.fi>, s32905u@saha.hut.fi (Jouni Ilari Polkko) writes:
> 
> I have noticed in pressure chamber at 50 m (164ft) that breathing is 
> heavier than in 1 AT pressure. However, I haven't noticed this during
> my dives to 50-60 m region. Maybe this is due to additional stress and 
> poor judgement becouse of narcosis in water diving, compared 
> to just sitting in the chamber in air.

Question: what's the difference between breathing air in a chamber under pressure
and breathing air (via scuba I assume :-) ) at an equivalent depth in water? 
Your body absorbs nitrogen due to elevated partial pressures (Henry's Law).  
Isn't pressure is pressure is pressure, whether water or air, or whatever, 
induced?  So, nitrogen (I assume) narcosis should be an equivalent problem in a
chamber ... yes/no?

Is there a doctor in the house?

-- 
Karl F. Schutz
PADI DM-50321
From: gd@gehenna.sw.stratus.com (Greg Dawe)
Newsgroups: rec.scuba
Subject: Re: dangerous misconception (was Re: Human bodies explode...)
Date: 19 Nov 92 17:52:13 GMT
Organization: Stratus Computer, Software Engineering
NNTP-Posting-Host: gehenna.sw.stratus.com

In article <1992Nov19.145745.9605@mailer.cc.fsu.edu> mayne@cs.fsu.edu writes:
>One of my instructors told me that he got experienced O_2 toxicity
>while decompressing on pure oxygen. He had enough warning to switch to
>air and avoided problems.

I recently experienced symptoms of an impending CNS OX/TOX hit while 
decompressing on a rich NITROX mixture (EAN50).  I was at 49 FSW, well within 
the maximum operating depth (MOD) of the mix, when out of nowhere I felt 
nauseous and the beginnings of a headache.  I checked my depth, just in case 
the ascent line I was on had shifted and dropped me deeper than I should have 
been, and switched to air.  The symptoms went away in a few minutes.

In retrospect, I had 2 predisposing factors: a fair exercise load, and a bit
of anxiety - I was attempting to deal with a nearly out-of-air buddy and
a charter boat which had pulled its anchor, leaving me to deploy my lift bag
ascent line.  While hanging on the line a lobster boat drove over the lift
bag, but fortunately it didn't dump.  Needless to say, I had a fair bit of
physical and mental stress just prior to noticing the nausea.

The IAND NITROX diver manual states that, "exercise greatly reduces a diver's
tolerance to oxygen".

I think this needs more emphasis.  In my "neck of the woods" most of my
friends switched from using pure O2 on the shallow stops, to using EAN50
because it's generally perceived to be safer, and you can start breathing
it sooner.  This perception is probably faulty.  Sure, PO2 and exposure time
are important, but so is the workload.  Speaking for myself I know how 
careful I am when decompressing on pure O2, but I must admit that I let my 
guard down a bit when I started using EAN50.  Never again!
-- 
Greg Dawe                        | Disclaimer: I don't speak for my employer,
Voice : (508)-490-6666           |             nor they for me...
e-mail: Greg_Dawe@vos.stratus.com|
From: dank@calvin.usc.edu (Dan King)
Newsgroups: rec.scuba
Subject: Diving around Washington, DC?
Date: 23 Nov 92 03:48:59 GMT
Article-I.D.: calvin.1ercjbINNrf3
Reply-To: dank@usc.edu
Distribution: world
Organization: University of Southern California, Los Angeles, CA
NNTP-Posting-Host: calvin.usc.edu


I'm graduating soon from USC and it looks like I might be going to
Washington DC to work but I cringe at the thought of leaving the
easy, fun diving around Southern California.

Does anyone know what diving is like around Washington ("around"
being anywhere with four or so driving hours)?

Thanks!
dank
Newsgroups: rec.scuba
From: dan@resonex.com (Dan Kell)
Subject: Re: Down Currents (Was Cancun or Coz)
Organization: Resonex Inc., Sunnyvale CA
Date: Thu, 19 Nov 1992 15:42:59 GMT

In article <9211190742.AA26645@deepthought.cs.utexas.edu> RFLNG@CLEMSON.CLEMSON.EDU (Reef Fish      , Large Nassau Grouper) writes:
>kkwwkk@mixcom.com (TA Shaw)  <1992Nov18.151430.14419@mixcom.com> says
>
>> b) I was told that from time to time, the currents that run off the
>>    wall can be dangerous.  That if the conditions are right, it actually
>>    can be like flushing a toilet, ie the current is so strong running
>>    over the and down the wall that it will drag divers down even if
>>    their BC is inflated?  Anyone else heard of this?
>
>IMO this "death grip down current" is one of the popular diving myths,
>I've done hundreds of dives in Cozumel ... the current can be VERY swift,
>at times, but I've NEVER experienced the slightest "current running over
>and down the wall", in Cozumel, or in other swift-current sites.
>
>In all reported cases I've heard or read about "strong down current", an
>analysis could be made that the diver simply lost buoyancy control (usually
>an inexperienced diver, forgetting to inflate the BC at depth to compensate
>for wet/dry-suit/BC-compression) to cause the "down draft", and by the time
>such diver realizes s/he is being "dragged down", no inflation of BC is
>going to arrest the descent instantaneously -- and so the current gets
>blamed for the down-dragging, and inexperience/panic distorted the rest of
>the explanation.
>

There was a discussion, some months? ago, about this phenomena. It does
exist. I read an article some time ago in National Geographic about Monterey
bay that talked about down currents being an erosive force in the Monterey 
Canyon. Cozumel was mentioned in the discussion quite extensively if I 
remember right. I seem to remember something about the sand falls down
there also. What ever.

I tend to disagree that loss of buoyancy control can be blamed for this.
Even a brand new diver should be able to feel the difference between being
pushed down by a current and descending due to being negatively bouyant.
I know the first times I dove anywhere with a current I gained a very
quick and real appreciation of just how helpless you are in a current.
Big strong macho divers that we are (you ladies seem to have more sense
than us males B-) ), we are not fish. I sure can't out swim anything
we fins, I've tried. Somebody made the comment that if caught in a
down current to swim towards the wall. I remember the consensus being
that swimming away from the wall was the quickest way out of the 
current. (Somebody mentioned swimming toward the wall, this may do
nothing more than getting you smashed into the wall and pushed deeper.)

If I'm wrong please feel free to correct me. B-))


-- 
Dan Kell                  
email to dan@resonex.com
"Imagination is more important than knowledge."   A. Einstein
Newsgroups: rec.scuba
From: scairns@is.morgan.com (Scott Cairns)
Subject: Re: Dive shops in NYC
Organization: Fusion Systems Group
Date: Fri, 20 Nov 1992 14:26:22 GMT

Pan Aqua Diving
W.75th Street / Columbus Ave.

Paragon Sporting Goods
Dive Shop - 2nd Floor
17th & Broadway

Scuba Network
The Flatiron Building
Fifth Avenue
between 22nd & 23rd 


-- 
+------------------------------------------------------------------+
| Scott Cairns           	|   email: scairns@fsg.com         |
| Fusion Systems Group		|      or: scairns@is.morgan.com   |
| New York, New York, USA   	|                                  |
+------------------------------------------------------------------+
| Standard disclaimers apply.   				   | 
+------------------------------------------------------------------+
| Better not take a dog on the space shuttle, because if he sticks |
| his head out the window coming home, his face might burn up.     |
|    					- Jack Handey		   |
+------------------------------------------------------------------+
Newsgroups: rec.scuba
From: adb@herboid.uucp (Anthony DeBoer)
Subject: Re: dangerous misconception
Organization: Linda's Dragon Memorial Society
Date: Mon, 16 Nov 1992 13:49:56 GMT

David Weingarten <davidw@cie.uoregon.edu> writes:
>At 300', OXYGEN TOXICITY occurs.  This an ENTIRELY DIFFERENT
>problem and is MUCH more hazardous.  Oxygen Toxicity happens
>suddenly and as subtly as a sledgehammer to your head.  It
>causes violent convulsions and unconsciousness, and, as a result,
>death.  This is not something that we are individually susceptible
>to; it's pretty uniformally deadly, at about 298'.

Um, it's my understanding that there are a few individual-susceptibility
factors that enter into it; it's not like everybody is perfectly safe at
297' and dead at 299'.  Also, work level makes a big difference.  If
you're resting, you can take a much higher partial pressure of oxygen than
if you're exerting yourself.

A depth of 297' (seawater) corresponds to an absolute pressure of ten
atmospheres.  On air, the ppO2 is approximately two atmospheres.  This is
the same as breathing pure oxygen at 33'.  From what I've read about
oxygen rebreathers and using oxygen at decompression stops, this is the
depth you don't exceed, and 20' is a much safer limit.  This would
correspond to 231' on air.  So I'd be real wary about going anywhere past
200' on air.

Disclaimer: I don't use pure oxygen on dives, and I've never been anywhere
near 200' either.  I don't object to such types of diving, but I'm real
disinclined to doing any of this lightly or pushing the edges of any
envelopes.
-- 
Anthony DeBoer   NAUI # Z8800, D5482 | Why watch TV, when Netnews provides
adb@herboid.uucp | adb@geac.com      | 100% of your daily requirement for
uunet!geac!herboid!adb               | trivia and meaningless entertainment?
From: kehler@cs.chalmers.se (Carsten Kehler Holst)
Newsgroups: rec.scuba
Subject: Re: Sawtooth Profiles - Why not ?
Date: 24 Nov 92 00:48:43 GMT
Organization: Dept. of CS, Chalmers, Sweden

In <1992Nov23.124617.18245@csd.uwe.ac.uk> rj_sande@kiwi.uwe.ac.uk (Rob Sanders) writes:

>I am still a bit puzzled about the physiological reason against
>sawtooth profiles. I know that they encourage bubble formation, but
>could some enlightened person out there give a clear summary of how
>this occurs.

Enlightened (Ahrrm!). Well I've heard two explanations both of
which I believe one of which I understand.

1) When ascending pressure decreases and bubbles form. [As far as I 
   understand there is almost always some form of bubble formation.]
   Bubble formation in itself is not dangerous. Bends occur when 
   bubbles are caught in the capillars of the body. The type of
   bends depend on where the bubbles are caught. Worst case is if
   the bubbles are caught in the brain or other parts of the nervous
   system. Normally the bubbles are created in the veins and from 
   there brought back to the heart and into the lungs where they get
   caught and disolve harmlessly. 

   One of the dangers of Sawtooth profiles comes from the risk that
   these bubbles gets compressed again and therefore can pass through
   the lungs and be carried by the blodstream out to potentially 
   dangerous spots (like your brain).

   Another way bubbles can bypass the lungs is if you have some kind 
   of heart condition that allows blod to pass between the left and the
   right side of your heart [the word most often mumbled here is Patent
   Foramen Ovale]

2) When bubbles have formed they grow! So by doing a Sawtooth profile
   you end up with bigger bubbles that of not.

I don't know the precise relative merit of these two explanations, but
both seems good enough to me. 

>Also, can somebody explain _why_ nitrogen becomes narcotic at depth ?
>(I am not a biologist/chemist, but like to think I have reasonable
>mental faculties !)

I give up on that one :-) 

>Rob
>rj_sande@csd.uwe.ac.uk

Carsten Kehler Holst
Newsgroups: rec.scuba
From: schludermann@sscvx1.ssc.gov
Subject: Suitable Mechanical activator for homemade eutectic salt heatpack
Organization: Superconducting Super Collider Laboratory
Date: Tue, 17 Nov 1992 03:08:22 GMT

  What is a suitable mechanical activator for those eutectic heat packs?
I'm going to use sodium acetate. I thought of putting stainless steel
steel wool in a piece of flexible tubing, but that doesn't create much
of a shock.

Kris



Newsgroups: rec.scuba
From: leej@sgi.com (Lee Jones)
Newsgroups: rec.scuba
Subject: Re: Sekonic Marine Meter
Date: 17 Nov 1992 19:03:09 GMT
Organization: Silicon Graphics, Inc.
Distribution: na
NNTP-Posting-Host: diver.asd.sgi.com

In article <jkkqj0c@lynx.unm.edu> mulberry@triton.unm.edu writes:
>
>Sekonic Marine Meter II at a nice price.
>
>I would like to hear from U W photographers who have used
>this what they think of this light meter and if they feel
>that it has improved their photography.

Only to the degree that I needed to know what f-stop I wanted :-).  
Seriously, I have a Nikonos II, so I have no other source of information 
about how to set the f-stop.  Professional photographers have a saying:
"f-8 and be there", but it never seems to work for me, even if I *am* there.

My Sekonic has performed flawlessly for 6 years - it's also a standard among
real serious photographers (you often see pictures of Howard Hall and 
Marty Snyderman swimming around with their video units and a Sekonic bolted
on top).

Regards, Lee
Newsgroups: rec.scuba
From: craig@cattnts.canada.ncr.com (Craig Campbell)
Subject: Re: Caffeine and Diving
Organization: AT&T / NCR Canada Ltd., Toronto, Canada
Distribution: usa
Date: Tue, 17 Nov 1992 20:15:37 GMT

In article <1992Nov16.191431.27842@vestek.com> marcus@vestek.com (Mark Stephen) writes:
>     Does anyone have any info about the effects that caffeine can
>have while diving, or caffeine withdrawls ?

>     Marcus

	Don't do it, especially if you dive dry!!  I hate having to pee and
	not being able to.  (I will NOT go in my dry suit, YET...)
	Any other possible effects are far outweighed by this one
	consideration, by me.  Every time I drink coffee prior to a dive,
	I regret it.  Just say NO (thank you...no excuse for bad manners :-))

craig
-- 
Craig Campbell		|	These opinions are entirely the result of a 
Systems Engineer	|	small butterfly crashing into the far side
NCR Canada,		|	of the planet.  Chaos Rules.
an AT&T Company		|	I speak for no one, except, possibly, myself.
Newsgroups: rec.scuba
From: RFLNG@CLEMSON.CLEMSON.EDU (Reef Fish      , Large Nassau Grouper)
Newsgroups: rec.scuba
Subject: Sasha, Taca, etc.
Date: 16 Nov 1992 12:49:05 -0600
Organization: UTexas Mail-to-News Gateway
NNTP-Posting-Host: cs.utexas.edu

The last times I flew Taca and (Tan) Sasha airlines were 1 and 2 years ago
to Belize City (Belize) and Roatan (Honduras) respectively.

Given the close proximity of those cities, I'm considering a dive trip to
those places again, back to back this time, but not sure whether there're
any airlines that have connecting flights between Belize City and Roatan,
in either direction, on SATURDAYS, because I'm contemplating two consecutive
weeks of liveaboards.  My travel agent and another one I checked haven't
been of much help.  I would appreciate any info from anyone on rec-scuba or
SCUBA-L on that particular connection before I start calling travel agents
around the country.  You may reply publicly or e-mail me in private at

       RFLNG@clemson.bitnet     or     RFLNG@clemson.clemson.edu

Thanks.

-- Bob.
Newsgroups: rec.scuba
From: ds@scammell.ecos.tne.oz.au (Dale Smithyman)
Subject: Re: Shark Hunt to begin in Hawaii
Organization: Telecom Australia, Information Technology Development
Date: Mon, 23 Nov 1992 00:59:50 GMT

Are there any groups opposing this? Surely there must be some concerned citizenswho think this is wrong. Is there anyone we can write to in order to register
our protest?

Keep the seas free.	
			Dale
(novice diver who wishes he could dive cheaper!)

-- 
-------------------------------------------------------------------------------
Dale Smithyman		ds@scammell.ecos.tne.oz.au
The views expressed here are not necessarily the same as those of my employer
(bless his unbleached cotton socks).
From: fgz@kodak.pa.dec.com (Federico Genoese-Zerbi)
Newsgroups: rec.scuba
Subject: Re: CMAS ( was: Re: Human bodies explode in vacuum? )
Date: 20 Nov 92 16:11:58 GMT
Reply-To: fgz@kodak.pa.dec.com (Federico Genoese-Zerbi)
Organization: Digital Equipment Corporation

In article <1992Nov20.125434.27880@nntp.hut.fi>, s32905u@saha.hut.fi (Jouni Ilari Polkko) writes:

> Here is nothing else than wrecks below 10 feet.
>
> Jouni Polkko


I must disagree!  I was diving up in your neck of the woods
(in fact, I think I was diving off your club's boat, I think)
last summer with Matti Leinio and Anni Simola.  We ran into
a school of herring at 80' that was simply awesome!

I guess it's just a matter of what each diver is looking for...

F.
Newsgroups: rec.scuba
From: borand@fws607.intel.com (Brady Orand)
Subject: Trade my computer gear for your SCUBA gear?
Organization: FES, INTeL Corporation, Folsom, CA
Date: Tue, 17 Nov 1992 21:25:13 GMT


  I am a new openwater diver and have very little gear of my
own.  HOWEVER, I have LOTS of excess computer/Novell/Networking
stuff.  Would anybody be interested in working out any trades?
I am in need of everything; wet suit, BC, Tank, regulator,
octopus, compass, dive computer, etc.   I have for possible
trade:

	Mac Stuff:

		Laserwriter IINTX 4 Meg memory upgrade (new)
		Kinetics Fastpath

	Novell Stuff:

		Novell Netware 2.15 rev C (255 user version)
		Novell Netware 2.15 rev C (25 user advanced)
		Netware C Libraries/Dev Kit
		Lan WP for DOS
		NFS for Netware v 1.2 (only works with 3.11)
		Novell Technical Reference Manual

	Networking Stuff:

		Lanworks Boot Proms for wd Elite 16 & 3Com 3C503 (new)
		WD (SMC) Elite 16 network cards (2) (new)
		Transceivers (AUI <-> Thinnet)
		
	Software:

		IBM's X-Windows for DOS (new)
		Quattro Pro 3.0 (new)
		MS Windows 3.0 (new)
		MS DOS 5.0 (new)
		Lotus 123 for Windows v 1.0

	Misc:
		Dexxa Mouse


Brady Orand
borand@pcocd2.intel.com
--
========================================================
 Brady Orand             | "Intelligent quote goes here.
 Intel Corportation      |  When I think of one, I'll 
 Folsom, Ca              |  add it."
 (916) 356-3877          |            - original
======================================================== 
Newsgroups: rec.scuba