HDTenEightyP/NetNews huggingface dataset:
From: story@sgi.com (David (Duis) Story)
Subject: Re: Any information about Cancun or Cozumel
Organization: Silicon Graphics, Inc.
Date: Mon, 23 Nov 92 20:08:15 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.

I know it's dangerous, but I feel I have to relate personal experience
which might contradict Bob's well-researched conclusions.

Diving in heavy surge in Monterey over the top of a pinnacle, I
noticed very strong "downdrafts" on either side of the pinnacle.  I
was neutrally buoyant, hovering at about 30', while heavy surge was
moving me approximately 40' in the horizontal direction on each swing.

>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.

Despite being an experienced Monterey diver, with my BC and drysuit
properly inflated for neutral buoyancy, and being very aware of my
depth relative to a fixed object (the hard corals on the pinnacle were
demanding my attention :), I was still "dragged down" after each pass
across the top of the pinnacle.  Likewise, I was "forced up" on each
return trip, only to be dragged down again.

The net effect, of course, was a downward motion -- since the suit
compressed on the downdraft, I fell slowly in the idle period between
the surges, and if I had not maintained my depth between surges, I
would have descended enough to have been smacked into the pinnacle on
the return trip!

I agree with Bob's research, but feel that he may be overlooking that
the *initial onset* (say the first 10-15') of "down draft" may be
quite a real phenomenon, and hard to fight.  After that initial down
draft, however, I concur that an experienced diver would be able to
recover quite well, and that any diver with decent buoyancy control
would have no troubles.

Cheers,

David Story                        NAUI AI Z9588, PADI DM 43922, EMT
story@bent.wpd.sgi.com             Better diving through tolerance.

Newsgroups: rec.scuba
From: dave@hpdstma.ptp.hp.com (Dave Waller)
Subject: Re: Human bodies explode in vacuum?
Organization: Hewlett Packard
Date: Fri, 20 Nov 1992 16:47:58 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:
|> 
|> 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?

The bigest difference is in the method of delivery -- in a chamber you are
breathing air through a considerably larger orifice (your mouth) than while
on SCUBA (the second stage of a regulator).

In addition, despite the excellent job reg manufacturers have done in
designing regs that have a low cracking pressure, the very nature of a demand
regulator REQUIRES that there be a cracking pressure, and hence, this is
something your lungs have to work against that they don't while simply
sitting on a pressurized chamber.

For these reasons, it is always more work to breath off a regulator than
in a chamber that is pressurized to an equivalent depth.

|> 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?

Yes, and yoru analysis is essentially correct.

With regard to the question of has anyone experienced increased breathing
resistance due to increased gas density at depth, I have, to a notable, but
not interfering, degree. This has been at extreme depth, however. I have not
noted this difference at typical recreational diving depths.

-- 
Dave Waller
YMCA Instructor
Newsgroups: rec.scuba
From: david@monymsys.mony.com (David Kozinn)
Subject: How do professionals decompress (was Terminology (and other things))
Keywords: SCUBA, BSAC
Organization: Mutual of New York
Date: Mon, 23 Nov 92 18:57:20 GMT

In article <1992Nov20.165902.3569@jet.uk> evdg@jet.uk (Erik van der Goot) writes:
>
>With respect to Lee Vogt's posting I would like to say that:
>a: 
>carrying out dives with planned decompression stops has got nothing to do with
>professional diving or recreational diving. As a matter of fact, most
>professional divers would never do planned 'in water' decompression stops.
>they get hauled out of the water and plonked into a surface decompression
>facility. 

I'd never given much thought to what the "pros" do, so this is an interesting
comment to me. 

A couple of questions: What kind of problems, if any, are associated
with climbing out of the water and jumping into a chamber as opposed to doing
in-water decompression? How critical is the time factor? (i.e., do you have x
minutes from surface time to get into the chamber to prevent a bends hit?)
-- 
David Kozinn                  | UUCP:   uupsi!monymsys!david
Mutual of New York  MD 75-14  | Domain: david@mony.com
Glenpointe Centre West        | GEnie:  D.KOZINN 
Teaneck, NJ 07666-6888        | Phone:  +1-201-907-6990
Newsgroups: rec.scuba
From: tierney@nevada.edu (TIMOTHY P TIERNEY)
Subject: Re: Diving in CA over Thanksgiving
Organization: University of Nevada System Computing Services
Date: Thu, 19 Nov 1992 20:46:44 GMT

In article <cofer.27@utkvx.utk.edu> cofer@utkvx.utk.edu writes:
>I am also going to California over Thanksgiving.  I will be leaving for San 
>Diego Saturday.  Any recommended sites or shops?  I also plan to drive up to 
>Las Vegas, and perhaps over to the Grand Canyon.  I would not think these 
>would be good dive locations, but never having been there, I don't know.  
>Any suggestions would be appreciated.

We happen to have to largest man-made lake, Lake Mead here and there is
decent diving there including sunken boats and old rock plants that were
used in the construction of Hoover Dam.  Plus, if you dive in the canyon
immediately in front of the dam you can find old drill bits and various
other stuff used during construction.  Water temp currently ~65 degrees.

You can also dive the Colorado River below the dam.

Vegas.  It's not just for gambling any more.

Tim Tierney
NAUI Advanced


Organization: Carnegie Mellon, Pittsburgh, PA
From: geary%cfa3.DECNET@cfa.harvard.edu
Newsgroups: rec.scuba
Subject: Grand Turk diving
Date: 21 Nov 1992 13:43:38 -0600
Organization: UTexas Mail-to-News Gateway
NNTP-Posting-Host: cs.utexas.edu

To Jeff Maurer:

     Many thanx for your nice posting on Grand Turk diving, in
response to my request for info.  I didn't get any poop on condos,
so we will probably try to book something at the advertised inns. 
I am a fanatic shore diver (I hate regimented boat dives) and hope
to try out the beaches of G. Turk wherever they get close to the reef
(yes, I recall that this seemed to be only on the north and south
extremities).

     You mentioned Salt Cay.  We spent a week there, and with one
VERY notable exception, the diving was really ho-hum (to be charit-
able).  The big exception was our one dive (only one allowed) on
the Endymion, a 40-gun British frigate sunk in 1790.  Way out in
the waves, in a totally unsuitable dive boat (their old flat-bottom
LCM from WWII).  Bruise-city for my wife, but still a really memo-
rable undisturbed shallow wreck dive, unlike anything else to be
had in the Caribbean.

             OOo O                John C. Geary
             O oO                 PADI DM-52283
              o                   geary@cfa.harvard.edu
       _____ o o
      (_/-\_)..
     ===(O).
From: gd@gehenna.sw.stratus.com (Greg Dawe)
Newsgroups: rec.scuba
Subject: Re: dangerous misconception (was Re: Human bodies explode...)
Date: 16 Nov 92 15:08:02 GMT
Organization: Stratus Computer, Software Engineering
NNTP-Posting-Host: gehenna.sw.stratus.com

In article <1992Nov16.074547.5322@nntp.uoregon.edu> davidw@cie.uoregon.edu (David Weingarten) writes:
>Anybody diving to 200' and deeper is going to be SERIOUSLY narc'ed.
>Whether they feel panicky, euphoric or start hallucinating varies
>from person to person.

You're right about the individual susceptability.  In fact, the susceptability
varies from person to person, from day to day, and from dive to dive.  Other
factors include the depth (which you mentioned), and the activity level - the
more you exert, the more narc'd you get.

On a more technical note, it's not completely accurate to state that "anybody
diving to 200' and deeper is going to be SERIOUSLY narc'd".  There are some
divers who are able to function well at 200 FSW, and a rare few, who can
function well even deeper.  These divers have been diving deep on air for
years, and have developed some tolerance for the symptoms of narcosis.  They
also understand their body's limitations while "under the influence" and don't
stray too far from the anchor line, nor do they exert themselves.

This tolerance, or adaptation is finite.  It has a "bottom" (as opposed to
a ceiling), and can be lost if the diver doesn't continue to dive deep.  
In areas of seasonal diving, such as New England and Long Island, deep divers
spend the initial part of the season diving progressively deeper to regain
their deep adaptation/tolerance.

I have purposely left out mention of CNS Oxygen Toxicity - a serious 
consideration - in order keep this posting short, and to the point.

Please note, I am NOT advocating any particular form or practice of diving - 
especially deep diving.  Everyone should always dive within their limits of
training, comfort, and experience.  This posting is intended for discussion
purposes only.  Don't take my word on anything - read and educate yourself!

More information about this can be found in Brett Gilliam's "Deep Diving"
and several articles appearing in the AquaCorps DEEP issue.  Also, somebody
belonging to UHMS published a paper on progressive adaptation to narcosis.  
Any net.divers know who, or have a copy?
-- 
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: phil@seidel.ucsb.edu (Philip Papadopoulos)
Newsgroups: rec.scuba
Subject: Re: Shark Hunt to begin in Hawaii
Date: 18 Nov 92 22:54:04 GMT

teshima@uhunix.uhcc.Hawaii.Edu (A. Lani Teshima) writes:

>It was just announced today by the state Dept. of Land & Natural
>Resources that the state will be actively hunting tiger sharks larger
>than 8 feet long on the island of Oahu, in areas known for tiger shark
>sightings (North Shore and west shore, primarily). This was agreed
>upon by a number of "experts" from difffernt spheres, including Jerry
>Crow from the Waikiki Aquarium.


>Looks like the state's finally caved in to numerous pressure groups.

This truly is a sad commentary on the human race.  Just because a 
surfer gets himself bit by a tiger shark, we're going to wipe out
all 8+ footers. Afterall, it really is our ocean, isn't it?
Sharks scare me as much as they scare anybody, but this is a really
ludicrous solution.  How about putting floating dummies on surfboards
and find out which tigers attack the bait.  Then fish and eat that particular
shark (or sharks).  Anybody thought of figuring out WHY the sharks
are attacking humans before we start on wholesale destruction?

I recall several years ago (maybe 10-15) thousands of Hammerhead Sharks were
coming into 3ft of water at South Padre Island, Texas.  Some were 10-12 footers
and mean.  I don't recall any talk of extermination.  Who would of thought that
Texans had more brain cells than Hawaiians ;).


Phil
From: story@sgi.com (David (Duis) Story)
Subject: Re: recommendations on dive computers and BCs sought
Keywords: dive computers, BCs, regulators
Organization: Silicon Graphics, Inc.
Date: Wed, 18 Nov 92 19:18:07 GMT

In article <1992Nov16.202120.15769@walter.bellcore.com> andre@broccoli.bae.bellcore.com (Andre Cosma) writes:
>
>[...]  I seem to remember that the topic 
>of user-replaceable batteries has come up on the net before and there 
>was at least one model which takes standard-size batteries, as opposed 
>to the Orca, which takes the special battery.)

The EIT/Orca Delphi takes standard 9V batteries, though Lithium
batteries last a lot longer and are more consistent in cold water.

The Oceanic DataMax Pro takes a somewhat "standard" K-cell battery.
I'm not sure whether that's available in lithium.

Cheers,

David Story                        NAUI AI Z9588, PADI DM 43922, EMT
story@bent.wpd.sgi.com		  Better diving through computers.

Newsgroups: rec.scuba
From: volkoffb@nextnet.csus.edu (brian volkoff)
Subject: Re: Cheap hotel/motels in Monterey
Organization: California State University Sacramento
Date: Tue, 17 Nov 1992 03:58:24 GMT

>>In article <BxKG42.KvL@inews.Intel.COM> brodesky@td2cad.intel.com
>>(Michael Brodesky) writes:
>>>
>>>Are there and good cheap hotel places to stay in. 

When I've gone to Monterey with the classes from the university here,
we've always stayed at the Sea Breeze motel in Pacific Grove.  It's a
nice quiet place.  For a room with three beds and a kitchen it was
$65/night (though somehow we ended up only paying $12.50 a person
last time we were there mid-week).

The Sea Breeze is on Lighthouse towards the end (I think the closest
cross-street is Jewel).
-- 
Brian Volkoff
  volkoffb@nextnet.ccs.csus.edu
From: root@summer.bt.co.uk (Bob Baal)
Newsgroups: rec.scuba
Subject: Re: PADI Diving depths
Date: 23 Nov 92 13:53:39 GMT
Organization: BTLabs

From article <1992Nov19.151154.10005@mailer.cc.fsu.edu>, by mayne@phi.cs.fsu.edu (William Mayne):
> 
> I'm not a fan or defender of PADI, but since I may have given the
> wrong impression by the above I will try to correct it. PADI, like
> CMAS, teaches that you aren't supposed to go deeper than 60 feet
> (CMAS 20 m) on the first certificate. I took only the first course
> 
> Bill Mayne

Thats interesting I did my scuba course with PADI and never remember
that being said. The third dive I ever did was to 60 feet. That dive
was me 8 other novices and one instructor. I lost the instructor and
swam arount for a while on my own then went up, I am certain I was at
down at least 60ft.

Another interesting thing about that course was they forgot to tell
us how importand controlling your accent rate was. I read about it in a book
and on the second dive (45ft) was the first to start up. I later found out
I went up to quickly but the rest of the course all over took me.!



#include <Std disclaimer>
Bob Baal bob@summer.bt.co.uk
G7HZV @ GB7MXM CIS:100012,36
From: dunger@crsa.bu.edu (David Unger)
Newsgroups: rec.scuba
Subject: Re: Shark Hunt to begin in Hawaii
Date: 18 Nov 92 15:25:17 GMT
Organization: Boston University Center for Remote Sensing


	Thats really too bad, I wish someone would hunt
the statespeople so they could see how it feels.
Newsgroups: rec.scuba
From: paylor@ganzer.ecs.umass.edu ()
Subject: Solomon Islands - Tank connectors?
Organization: University of Massachusetts, Amherst
Date: Fri, 20 Nov 1992 14:57:46 GMT

I will be in Honiara, Solomon Islands for a few weeks in January, and
I hope to get some diving in.  One question I have, that I haven't
seen addressed in the archives, is: Do they use the US yoke style
fitting on the tanks there, or the European DIN connector?

Perhaps one of you who has been there can tell me?  And I'd like to
thank everyone who contributed information to the archive article on
the Solomons.

Thanks,
Andrew Paylor
paylor@ecs.umass.edu
Newsgroups: rec.scuba
From: rrrucke@srv.PacBell.COM (Rod Rucker)
Subject: Re: Any information about Cancun or Cozumel
Organization: Pacific * Bell
Date: Fri, 20 Nov 1992 00:32:55 GMT

In article <3930@master.CNA.TEK.COM> danbe@master.CNA.TEK.COM (Dan Beougher) writes:
>
>>  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
>
>I just got back from Belize and heard a chilling story of the same
>type related to me from a divemaster back at the shop after our
>dive:
>
> (Story deleted)

>I believed his story in that he wasn't a bullshitter type and
                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^
			      Yes, he was.
>it seemed plausible.
^^^^^^^^^^^^^^^^^^^^
  No, it wasn't.
>

Sometime's I'll tell you about killer abalone.  Fast movers they
are, with great eyesight.  Sometimes divers get their hand trapped
under them and they drown. :-)  

-- 
Rod Rucker
rrrucke@srv.PacBell.COM
PADI DM-47240

Newsgroups: rec.scuba
From: rob@blacks.jpl.nasa.gov (Rob Fatland)
Subject: No!!!  More Delusions and Sophistry to Justify the Great Shark Hunt!
Organization: Image Analysis Systems Group, JPL
Date: Fri, 20 Nov 1992 21:21:15 GMT

pbray@sloth.Reed.Edu (Peter Bray) writes:

[paragraph on killing tiger sharks being ok]

[paragraph on the behavior and nature of tiger sharks]

[paragraph on the eating of mako sharks]

to which I respond:

o this isn't about how appropriate it is to kill tiger sharks based on 
some clever and clearly incomplete arguments based on a partial under-
standing of marine biology.  It is about trying to solve a problem 
by Killing Something.  Kill Something!  Kill Anything!  Kill!

o I may be eaten by a shark someday, but I refuse to ask that
diving be Made Safe As Bowling.

o It is a standard and vile ploy of the sophist to bring in
other problems to try and muddy the original.  Shame on those 
Japanese businessmen, but far away from this issue...

I seriously doubt that The Great Shark Hunt will affect what goes on below
sea level.  Am I cynical to suggest it will merely appease voters, burn
some money, give some government officials a paid fishing trip, and set
a precedent for wanton arbitrary genocide for the sake of coddling an 
increasingly insulated, ignorant race of ape-descended planet-trashing
gun-slinging Logicians (who still think digital watches are a pretty 
neat idea)?

Anyway, off to write my letter, and then to the FAX machine!  

'Gobern de Shark!'       -Herman Melville
'Smile, you sonofabitch' -Chief Brody

rf
--

Gobern de shark!
From: ps3p+@andrew.cmu.edu (Peter A. Simon)
Newsgroups: rec.scuba
Subject: Re: Free ascent
Date: 22 Nov 92 22:00:15 GMT
Organization: Carnegie Mellon, Pittsburgh, PA

Excerpts from netnews.rec.scuba: 19-Nov-92 Re: Human bodies explode in..
by Anthony DeBoer@herboid.u 
> >be cautious about going deep. I doubt that most peoplm could do a
> >successful free ascent from 130 feet in case of total air loss, starting
> >without a fresh breath. At least it would be risky. Also air supply goes
> >quickly at depth and I'm told that some people actually don't have it
> >together well enoug` to monitor their time, depth, and air supply.
>  
> I know a couple of divers who did an emergency ascent from 150' without
> any further problems (one had a freeflow that they couldn't straighten
> out, and the other was narked enough to follow his buddy when he went
> ballistic), but yes, it is a risky thing.

I did my first emergency free ascent from 80' with no problem because
every time I ascended from the wreck we were diving on (three times a
day for 4 weeks before the incident) I did a free ascent "just for
practice."  I was damn glad I did when my reg finally self-destructed. 
I remembered the only thing I had to and that was to EXHALE.  Luckily, I
didn't miss any decompression stops.

The second time was from 200' where I had run out of air and believe me,
it was scary.  Again, though, successful, because I had continued my
practice to come up without the regulator in my mouth "just for
practice" from depths as deep as 150' to my first stop.

I would be interested in reading comments (not flames) pro and con on
recreational divers practicing "just in case."  

Peter 
NAUI Inst. #1434
Newsgroups: rec.scuba
From: dan@resonex.com (Dan Kell)
Subject: Re: Re-loading Fuji Disposables
Organization: Resonex Inc., Sunnyvale CA
Date: Wed, 18 Nov 1992 10:51:16 GMT

In article <1992Nov17.032803.1557@herboid.uucp> adb@herboid.uucp (Anthony DeBoer) writes:
>Dan Kell <dan@resonex.com> writes:
>> [ primer on how to reload film ]
>>... And I apologize
>>for the length but this is kind of hard to explain sight unseen!
>
>But didn't you just say we're _supposed_ to load the film sight unseen?  O-)
>-- 

That's why I always wear my blindfold when I re-load my cameras!


-- 
Dan Kell                  
email to dan@resonex.com
"Imagination is more important than knowledge."   A. Einstein
From: ray@tsw.UUCP (Ray Izumi)
Newsgroups: rec.scuba
Subject: Re: LIGHTHOUSE REEF RESORT
Date: 23 Nov 92 14:58:33 GMT
Organization: The System Works, Redmond, WA

In article <John_Mitchell-221192154631@mac84041.educ.ualberta.ca> John_Mitchell@psych. edu.ualberta.ca (John J. Mitchell) writes:
>I AM INTERESTED IN SPENDING A WEEK AT LIGHTHOUSE REEF OFF BELIZE CITY. 
>ANYONE ABLE TO SHARE INFORMATION WITH ME ON THIS DIVE SPOT?  MY MAIN REASON
>FOR CHOOSING LIGHTHOUSE REEF IS TO DIVE THE BLUE HOLE, REPUTEDLY ONE OF THE
>WORLD'S GREAT DIVE SPOTS.  CAN ANYONE PROVIDE ME WITH DIVING INFORMATION ON
>(1) LIGHTRHOUSE REEF (2) THE BLUE HOLE.  Thanks.

While the Blue Hole is certainly an interesting dive, it's definitely not
worth planning an entire dive trip around. There is very little life in the
hole.

But the diving around is some of the best in the Caribbean. If you don't mind
doing only two dives per day, then the shore-based operations are OK. But for
maximum fun, get on a liveaboard. There are two excellent ones cruising the
area, the Belize Aggressor and the Peter Hughes boat Wave Dancer. Of the two,
I'd prefer the Dancer because it has more heads. Either boat will get you to
the Blue Hole, but I think you'll find that it is the other dives like Half
Moon Wall that you'll remember...

-- 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Ray Izumi, The System Works, Redmond, WA     206-823-4685      uunet!tsw!ray
"Put the pillow over your head, scream and cry - the garbage is coming!"
           - New York City Commissioner of Sanitation