HDTenEightyP/NetNews huggingface dataset:
From: dave@hpdstma.ptp.hp.com (Dave Waller)
Subject: Re: Article in Current _SCUBA Times_
Organization: Hewlett Packard
Date: Fri, 21 Aug 1992 18:50:12 GMT

In article <BtB3Cv.HwJ@ais.org>, tim@ais.org (Tim Tyler) writes:

|>      Then I stared in disbelief at the line "I was pretty sure I
|> was the only person in the water that night for miles. I liked that
|> thought."
|> 
|>      I think the article is a clear demonstration that stupidity
|> (not to mention irresponsibility, for daring to condone the solo
|> night/cold-water/wreck/current dive in Scuba Today) isn't just a
|> sign of novice divers.  Marty's article shows that it can be a
|> symptom of anyone, regardless of dive equipment, qualifications, or
|> experience. I guess for that, I am thankful to him and Scuba Today.

It is far from a settled issue that solo diving is "irresponsible". Indeed,
there are many in this forum who engage in such a practice, and there has
been lively discussion in the past on this topic. I put forth some suggestions
for rules that should be adhered to for solo diving last year as a starting
point for discussion on this topic, and am still interested in developing
a course for solo diving; I am only holding off on this until I complete
a NAUI crossover, because I would like to seek sanction first from NAUI
before hitting up the YMCA (they tend to be irrationally rabid about the
buddy concept).

To close your eyes and ears and pretend that the buddy system paradigm is
the law of the land, and has some sortof proven track record as the safest
method to emply while diving is foolish. Statistics seem to suggest that
belief in the added safety of the buddy system may be misfounded.

I address only your attack on the solo element of this individual's account
as "stupid", in the hope that you may reconsider your strident opinion. As
for the other points, well, I can't argue those -- currents and sharks at
night are something that would likely keep me out of the water at night.

Further, without appropriate precautions, solo diving *can* be quite
reckless. However, it is not necessarily so regardless.

-- 
Dave Waller
YMCA Instructor
Newsgroups: rec.scuba
From: rwu@ismdqa.intel.com (Ronnie Wu )
Subject: Dry suit buoyance control
Organization: Intel Corp.
Distribution: usa
Date: Thu, 13 Aug 1992 22:34:34 GMT

>Can any of you drysuit experts explain how to handle
>boyancy control with drysuits? I have only 25 dives

	1. Never use it to replace the BC.

	2. Put only enough air to compensate squeezes.

	3. Practice fill/dump air in the pool before taking the first
	   dive in the ocean/lake/river...

	The setup I use for practice is a 2-3 feet long rope, one end
	tie to a 40 lb weight on the bottom of the pool (2 X 20 lb weight
	belts), one end to the BC (chest). Then I can try fill the suit
	without worry about an uncontroled ascend. Try right yourself 
	from an inverted position, try rapid air dump, and measure how
	much weight you need to be neutrally buoyant at 10 feet (take
	in consideration the difference between fresh and salt water).

Ron

====================================== I don't speak for Intel =========

Newsgroups: rec.scuba
From: dave@hpdstma.ptp.hp.com (Dave Waller)
Subject: Re: computer recomendations?
Organization: Hewlett Packard
Date: Fri, 21 Aug 1992 21:11:17 GMT

In article <9208211735.AA18890@shogun.smos.com>, joseph@shogun.smos.com (Joseph Crunk) writes:

|> CAUTION! Your (mine, and everyone elses) computer is rated to a given depth
|> by the manufacturer. This depth is the deepest that computer is KNOWN to
|> function. Taking it below that depth may result in incorrect decompression
|> calculations as well as incorrect depth sensing. For this reason, depending
|> on a computer taken to *****CENSORED***** depth can be a really dangerous
|> thing to do. I'd use every caution when even approaching the rated depth.

Excellent point.

|> Note: most computers are rated for a depth in excess of 130 fsw. I'd have to
|> look it up but I think the Delphi was rated to either 190 or 200 ft. In the
|> book 'Deep Diving' Gilliam notes that an Aladin accurately calculated the
|> depth in excess of 500 fsw, altho it's rated to 330 fsw. Your computer's
|> mileage may vary.

I dive with a Delphi Pro. It is rated to 299, and makes accurate calculations
within that range. The censored depth was shallower than 299 feet; that's as
much as I'll say.

|> Also, there's no military, scientific, or commercial applications for diving
|> when you're *_HEAVILY_* narc'd. I'd be hard pressed to find a sports diving
|> application, other than pure entertainment :-) All-in-all, this kind of 
|> diving is a little to close to the edge for my comfort.

No problem. I was quite comfortable under the conditions, although I'll
readily admit that the motivation for being at that depth was dubious by
my own standards. Still, I wouldn't have been there if I didn't feel it
justified, now would I have been? :-)

-- 
Dave Waller
Hewlett-Packard Co.
Workstation Systems Division
Sunnyvale VAB Consulting
(408) 746-5324
Newsgroups: rec.scuba
From: pyron@skndiv.dseg.ti.com (Dillon Pyron)
Newsgroups: rec.scuba
Subject: Re: computer recomendations?
Date: 13 Aug 92 21:37:54 GMT
Reply-To: pyron@skndiv.dseg.ti.com
Organization: TI/DSEG VAX Support


In article <1992Aug12.232747.21137@ads.com>, patterso@ADS.COM (Tim J. Patterson) writes:
>I'm headed out for a week on a live aboard on the great barrier next
>week. I've called the local dive shops and have an option of renting
>one of 2 different dive computers for the trip. A "Skinny-Dipper" or a
>US Divers Monitor II.  The dipper is slightly cheaper but, I've never
>used a computer so have little to base a decision on.
>
>Any recommendations?
>
>Thanks,
>
>Tim
>
My wife and I have rented the Skinny Dipper, and several of the instructors I
work with use them.  They are simple and have VERY LARGE numbers.  On the
negative, you have to turn them on, and they earned a nasty rep for flooding. 
I believe the Monitor II is the same machine as the Aladin?  If so, I have the
Pro, my wife has the Sport.  I really like it.

BTW.  If you're going to dive with one for a week, get ready to buy one when
you get back!!!  You'll be addicted.
--
Dillon Pyron                      | The opinions expressed are those of the
TI/DSEG Lewisville VAX Support    | sender unless otherwise stated.
(214)462-3556 (when I'm here)     |
(214)492-4656 (when I'm home)     | Lawyers are like nuclear warheads, every-
pyron@skndiv.dseg.ti.com          | body has some, and when you use them, they 
                                    f*ck everything up.
                                                  Danny DeVito, _OPM_
From: jdale@cats.ucsc.edu (Jonathan Dale)
Newsgroups: rec.scuba
Subject: Good Prices on Tanks
Date: 22 Aug 92 07:19:47 GMT
Organization: University of California; Santa Cruz
NNTP-Posting-Host: si.ucsc.edu


I need a tank or two, within the next month or so, so I've started looking
around at prices.  I want an Aluminum 80 cu.ft. tank, because something
bigger would be excessive for what I do but I breathe too much for anything
smaller (I'm working on that).  Up here in Seattle, Wash (yeah, yeah, ignore
the header for the moment), they tend to run around $130, and "On Sale" means
$120, a whole 8.7% off.  Great.  Gee whiz.  Salesman told me that they cost
the store $95 wholesale, and they couldn't afford to drop it anymore, even
during their big once a year sale. Whee.  Okay, so I thought I'd try
mail-order.  Called this place in Florida, they tell me $130 by mail, but
if I walk in just $90.  Now there's a deal, and it sure looks like the salesman
above is giving me that typical dive-store BS (okay, dive stores fall into
two groups, ones that lie to you, and ones that overcharge; yes, I'm a cynic).
Well, this tells me mail-order is not the way to go -- $40 s/h? Not. But 
Florida is a long drive for a tank, you know?

SO, does anyone know a good place to get a tank?  I'll go anywhere on the
West Coast, no kidding, I have to drive down from here to school in Santa Cruz,
California anyway, so I may as well make a detour.  If there's a discount
for volume I might get 2 or 3 (I'm going to do a LOT of diving this year).  

BTW, I made the distribution USA, I doubt the rest of the world wants to know
where to buy tanks in the US.

Thanks in advance,

Jonathan Dale
NAUI Advanced & UCSC Research Diver
From: adb@herboid.uucp (Anthony DeBoer)
Subject: Re: ITC butterflies
Organization: Linda's Dragon Memorial Society
Date: Thu, 13 Aug 1992 03:36:14 GMT

David Weingarten <davidw@cie.uoregon.edu> writes:
>Ditch-and-don's are a cinch, the swimming exercises are a cinch, teaching
>skills I'm not worried about; things like the bailout I don't know about.
>I've done it, but it's not picture-perfect.  (The last time I did a 
>bailout I blew an o-ring right after donning my fins.)

Actually, if I was scoring you on that bailout, and you Did The Right Thing
in response to the O-ring blowout, you'd get extra points beyond what you'd
have gotten if everything had gone perfectly.  Not that I'm anywhere near
running ITC's (I still haven't even decided if I'll ever attend one as a
student yet), but from the divemaster perspective, handling problems and
preventing them from becoming full-blown emergencies counts for a lot.

BTW, have you completed an Assistant Instructor course?  A lot of the
material (including bailouts) is covered there, and taking that and
mastering those skills and using them for awhile before going to an ITC
should make that step a lot less steep.  I know you only need two out of
the three of DM, AI, or Instrutor Prep before an ITC, but I'd think about
stacking the deck in my favor by doing all three.
-- 
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: davew@hp-ptp.ptp.hp.com (Dave Waller)
Date: Mon, 17 Aug 1992 23:40:25 GMT
Subject: Re: Sport Divers' Inability to Calc Repetitive Dives
Organization: HP Pacific Technology Park - Sunnyvale, Ca.
Newsgroups: rec.scuba

Truly alarming.

Dave Waller
YMCA Instructor
Newsgroups: rec.scuba
From: peterson@hpl.hp.com (Chris Peterson)
Subject: Re: Boyancy control with drysuits
Date: Thu, 20 Aug 1992 22:32:25 GMT
Organization: Hewlett-Packard Laboratories, Palo Alto, California

In article <geYzuRq00WBME428Za@andrew.cmu.edu> "Peter A. Simon" <ps3p+@andrew.cmu.edu> writes:
>
>How about a preset dump valve?  It could be set to blow before the suit
>did or at some much lower pressure, to be determined empirically, that
>would allow sufficient differential for squeeze control but nothing over.
>
>-peter

I believe that some British dry suits incorporate an "AP valve" in the wrist or
ankle.  It is basically a "flapper valve" set to open a preset difference in
pressure between the inside and the outside of the suit.

I have never seen one (I've only read about them) and I'm not sure how well they
work.

As others have said, a little, regular practice, and conscious buoyancy control 
will handle most over-inflation/righting problems.
-- 
Chris Peterson                                     Hewlett-Packard Laboratories
                                                    Research Computing Services
                                                              Palo Alto, CA USA 
(415) 857-6432                                              peterson@hpl.hp.com
From: s32905u@saha.hut.fi (Jouni Ilari Polkko)
Newsgroups: rec.scuba
Subject: Re: periodic re-certification
Date: 19 Aug 92 07:30:34 GMT
Organization: Helsinki University of Technology, Finland

In article <930550@hp-ptp.ptp.hp.com> davew@hp-ptp.ptp.hp.com (Dave Waller) writes:

> Presently, except in extremely rare cases, certification cards issued by
> just about every certifying agency have no expiration. In other words,
> once certified, always certified.

 Nordic CMAS certification cards issued by national sportdiving associations
in Finland, Denmark, Norway and Sweden are valid for 5 years. To re-certify,
one must pass exam in safety regulations and have logged dives during last
two years. Re-certifying costs about USD20, that's the price of the new card.
Re-certifying must be done before card will become old. If one misses the 
deadline he/she must do something extra.

Jouni Polkko
CMAS P3 M1 
jpolkko@niksula.cs.hut.fi
Newsgroups: rec.scuba
From: sdodd@OES.ORST.EDU (Stephen M Dodd)
Subject: Re: just curious...
Organization: Oregon Extension Service, Oregon State University, Corvallis, Or.
Date: Wed, 19 Aug 1992 19:43:07 GMT

In article <1992Aug16.041711.21587@coelho.COM> drc@coelho.COM (david r coelho) writes:
>I recently went for a couple of dives and made the mistake of taking
>the wrong 1st stage setup which had no low-pressure hose for my drysuit.
>I proceeded with the dive anyway, and had no real difficulty getting to
>60 feet although the squeeze was a little uncomfortable.
>
>My question (just curiosity): what's the deapest anyone's gone in a
>drysuit without equalizing the dry suit?
>
>-- 
>david r. coelho                        email: drc@coelho.COM

  Interesting.  Of course this all has to do with the amount of
  insulation and possible extra weight.  

  I'll assume your question is asking for personal experiences.
  It is possible to get to the top of the reef here at ~35 feet with
  little attention to squeeze.  It is hard to recall, exactly, here in
  the office but I think I ignore it till after dropping down the side a
  bit.  That gets you away from any surge and there tends to be a quick
  adjustment of both divers equipment and various toys, which leaves you
  able to ignore the suit for much deeper.  I am sure by 70+ feet that
  most would have adjusted some.  That is where the excitement comes in,
  by the way.  If you expect to move up from 90+ feet without considering
  adjustments you may be surprised by an uncontrolled ascent right at
  your safety stop.   

  Steve

-- 
- Stephen M. Dodd, System Analyst, Oregon Extension Service
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
sdodd@oes.orst.edu          Internet          Oregon State University
503-737-0699                                  Corvallis, OR 97331
From: dodd@OES.ORST.EDU (Stirling S. Dodd)
Subject: Re: Tank thermal (de)compression question
Keywords: heat
Organization: Applied Research Laboratories, Austin, Texas
Date: Wed, 12 Aug 1992 12:30:05 GMT

In article <1992Aug11.144334.3439@engage.pko.dec.com> zipp@foosw6.enet.dec.com (Eric S. Zipp) writes:
>Greetings,
>
>	Ok all you bubble blowing physicists, refresh my memory with a bit
>of basic physics 101.
>
>	Upon compressing air in a tank, the process results in the generation
>of a good bit of heat (which is why the tanks are immersed in water during
>the process).
>
>	Upon venting a volume of air from the tank, the first stage, becomes
>quite cool(cold).
>
>	What exactly is generating/absorbing the heat during these processes?
>
>Inquiring minds want to know... ;-)
>
>Thanks,
>
>Eric 

If I'm not mistaken the culprit is Boyles Ideal Gas Law. Do you recognize:

PV=NRT

Pressure Times Volume equals the number of moles of the gas, times the
Gas Constant, times the Temperature.

Since the Volume is constant, When both the Pressure and the number of moles
drop, the Temperature drops. On filling the reverse occurs.


Clearly there is a balance equation involving the pressure and the number of 
moles that keeps everything in check, but I don't have my Statictical Mechanics
text handy. So long as the change is not Adiabatic, there will be a change in
temperature (by definition!)


By the way, I am a Bubble Blowing Physicist (3rd year Grad Student) and I
am doing research on the effects of underwater Bubbles on the ambient
noise in the Ocean, so if all of you divers would mind not farting while
I'm taking data I'd appreciate it! :{>

-- 
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
S Dod^2  |   "Do what you do but know why you're doing it"---GBH
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
From: sdodd@OES.ORST.EDU (Stephen M Dodd)
Newsgroups: rec.scuba
Subject: Re: Mask straps
Date: 21 Aug 92 06:01:02 GMT
Distribution: na
Organization: Oregon Extension Service, Oregon State University, Corvallis, Or.

In article <1992Aug17.181317.20252@meaddata.com> sharonc@meaddata.com writes:
>Does anyone out there have anything positive/negative to say about
>those fancy masks straps that you can buy to replace the regular
>plastic straps that come on your mask? (the "Slap Strap" is one brand
>name). My buddy from last May had one - it was made of neoprene (neon
>green). His had a "split", like regular mask straps, but I've seen
>some in magazines that are more like a cup that fits over back of
>your head.
>
    I like mine .... a little bit better than the others.  It will
    not break soon and it allows for one handing my mask clearing.
    The other day an instructor was asking some of us working on ditch
    and dons if we knew how to put our masks on with one hand.  He meant
    to do it by inhaling through the nose and then pulling the strap
    back over the head with the same hand.  He was a little annoyed with
    my repeatedly one handing my slap strap equiped mask with ease!

    Still, it's almost a gimmick.  I bought mine when replacing a broken
    nylon strap with what I thought would last a lot longer.

    Steve

-- 
- Stephen M. Dodd, System Analyst, Oregon Extension Service
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
sdodd@oes.orst.edu          Internet          Oregon State University
503-737-3550                                  Corvallis, OR 97331
From: FKK@SLACVM.SLAC.STANFORD.EDU
Newsgroups: rec.scuba
Subject: Re: DAN - should I join now?
Date: 20 Aug 92 23:12:12 GMT
Distribution: na
Organization: Stanford Linear Accelerator Center

I am curious about this info. Is DAN in trouble? What is the source of
this info?

I have been a memberof DAN for a couple of years.  The emergency transport
available for diving accidents was the reason.  Now that they cover all
emergency transport its even better. I am a climber and like the idea of
having the emergency help available.

Please keep us posted about DAN. Thanks
Newsgroups: rec.scuba
From: devetzis@dexter.bellcore.com (Taso N. Devetzis)
Subject: Thousand Islands/Eastern Lake Ontario Diving
Followup-To: poster
Keywords: info thousand islands ontario new york dive
Reply-To: devetzis@bellcore.com
Organization: Broadband Internetworking Research Group (Bellcore)
Distribution: na
Date: Wed, 19 Aug 92 21:55:57 GMT

I was thinking of setting up a dive trip with a friend to the
Thousand Islands area over the labour day weekend.  I drive
through the area quite often and find it very beautiful.  I am
looking for recommendations for good dive areas and shops (buddies
too, if you're interested).  Eastern Lake Ontario is fair game as
well.  We enjoy all types of diving -- wreck, river, drift, etc.
Any information (including local considerations -- ordinances and
the like) is very much appreciated.

Please e-mail.  I will summarize for the archives.

Thanks,
--taso

-- 
Taso N. Devetzis
Bellcore, 445 South Street, Room 2P-357, Morristown, NJ, 07962-1910, USA
devetzis@bellcore.com     ...!uunet!bellcore!devetzis
Newsgroups: rec.scuba
From: bmacmill@epas.utoronto.ca (Bruce MacMillan)
Subject: Looking for Used Dive Computers
Organization: University of Toronto - EPAS
Date: Wed, 19 Aug 1992 04:05:20 GMT

Hi: I am looking to purchase used or old stock dive computers and
other dive intrumentation of all types, models, and makes. Please contact
me if you have any information in this regard. Best wishes.

-- 
Bruce MacMillan
bmacmill@epas.utoronto.ca
Voice: (416) 599-9261	(519) 542-4572
FAX: (416) 978-8821	(519) 542-4854
From: sdodd@OES.ORST.EDU (Stephen M Dodd)
Newsgroups: rec.scuba
Subject: Re: Boyancy control with drysuits
Date: 18 Aug 92 06:17:02 GMT
Organization: Oregon Extension Service, Oregon State University, Corvallis, Or.

In article <1992Aug13.132914.24054@hellgate.utah.edu> rarobert@ursa9.cs.utah.edu (Robin Roberts) writes:
>>Do you use your BC for bouyancy or just the suit. Personally I use my
>>suit (I use a membrane, apparently not so easy with a neoprene suit)
>>for bouyancy. This means that I have to be correctly weighted close
>>to neutral bouyancy without any air in suit. If too heavy then more
>>air has to be put into the suit, which leads to the problems when rising
>>since there is much more air to dump and suit dumps are never as fast
>>as BC dumps at getting rid of air.
>
>i do not recommend using a dry suit for buoyancy control... even if you
>are also wearing a BC (i believe that you should always wear a BC with a
>dry suit, anyway)...  
>the BC is essential, for some of the reasons that are mentioned above, 
>such as the fact that a BC can be vented much faster than a dry suit.  
>IMHO, air in a dry suit is solely for the purpose of warmth and to 
>prevent squeeze.  As someone else in a previous posting suggested, 
>use the minimum amount of air in the suit that is necessary.  By using 
>less air in the suit, body positioning becomes less of an issue.  
>That is to say, it's still not a good idea to intentionally invert 
>(bye bye fins!), but it's less likely that you'll accidentally invert.  
>lots of extra air rolling around in your dry suit makes it very 
>difficult to control your positioning, etc.
>
>				rr.
>
>

  This is all a valid point of view within one school of thought.  The
  other school of thought would hold that one must adjust a dry suit all
  the time anyway over squeze and that one should dive with the lightest
  possible weight.  Large quantities of air in any bouyancy related
  equipment are to be avoided.  The easiest adjustment of such small
  quantities of air is for some best done in the dry suit.

  Anyway, much of the motivation for my earlier postings about dry suits
  and bouyancy control are related to observations of and conversations
  with professional divers who don't even use a BC when diving dry
  suits.  I have heard that european divers are known to dive this way
  as well.

  Anyway, a well weighted diver in a dry suit (light) can most easliy
  adjust bouyancy when carryining the minimum wieght.  As such the dry
  suit itself offers all the bouynacy control required.  The BC only
  offers surface flotation to them.  Such a diver only needs small
  adjustments, at one valve, over a wide range of depths for squeeze.
  It is assumed that such a diver would not casually flop over because
  of mismanagement of bouyancy in the suit.  I suppose experience has a
  lot to do with it.

  Steve


-- 
- Stephen M. Dodd, System Analyst, Oregon Extension Service
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
sdodd@oes.orst.edu          Internet          Oregon State University
503-737-0699                                  Corvallis, OR 97331