HDTenEightyP/NetNews huggingface dataset:
From: gregr@joyce.cs.su.oz.au (Greg Ryan)
Subject: computers as a backup to tables
Reply-To: gregr@cs.su.oz.au (Greg Ryan)
Organization: Basser Dept of Computer Science, University of Sydney, Australia
Date: Wed, 7 Oct 1992 03:21:40 GMT

Using tables as a backup for a dive computer (or computers) has been well
discussed in this group.  I thought it would be interesting to raise the
alternative - using a dive computer as a backup to tables.

Planning is an issue with all dives, but it becomes particularly important
in planned decompression dives.  Ensuring adequate gas supplies for bottom time,
ascent, deco and a comfortable margin for safety requires the dive profile to 
be worked out before you get in the water.  The  classic square profile is 
typical of diving the wrecks around Sydney and there is little multi-level 
advantage to be gained from computer use.  The use of tables, like Buhlmann's 
ZH-L12 or the DCIEM's, becomes entirely appropriate here provided you do the 
usual 'plan the dive, dive the plan'.

With experience of a particular wreck, it might be reasonable to later fall
back to computer based diving, once you are comfortable with the sort of
decompression profiles it will require you to do for that dive.

A dive computer still has a role though, as we all know about the best
laid plans.  A dive computer (preferably one using the same model as the tables 
you trust) provides a useful fallback when the dive is aborted well short of 
the planned bottom time.  Before computers were available I recall a few dives 
where on reaching the bottom (you could tell it was the bottom because you 
couldn't go any deeper without digging) the only reasonable decision was to
turn around.  Now rather than risk reading tables in this circumstance my buddy 
and I always fell back to the deco for the shortest dive we had planned, and
often this would be excessive for the now very short bottom time.
Having a computer calculating a profile for you to use as a backup is extremely
handy in this circumstance.

Does anyone else use their dive computer in this way?

				Greg Ryan	gregr@cs.su.oz.au
Newsgroups: rec.scuba
From: hdavies@rx.xerox.com (Hugh J.E. Davies)
Subject: Re: Buying an underwater camera in Hongkong
Reply-To: hdavies@rx.xerox.com
Organization: Rank Xerox Ltd.
Date: Wed, 30 Sep 1992 09:04:24 GMT

In article 22496@peanuts.informatik.uni-tuebingen.de, speckman@peanuts.informatik.uni-tuebingen.de (Heike Speckmann) writes:
>In november I will stay a few days in Hongkong. Now I am wondering if it is
>a good idea to look for a underwater camera, Nikonos or sea&sea for example, 
>because they are very expensive in Europe. Is there anybody who knows 
>prices or so ? I know that many "normal" cameras are much cheaper.
>
>Thank you in advance 
>
>Heike 
>-- 
>*****************************************************************************
>Heike Speckmann                 | E-Mail: speckman@peanuts.informatik.
>Universitaet Tuebingen          |               .uni-tuebingen.de
>Lehrstuhl fuer  Techn. Info.    |
>Sand 13                         | THE REAL GRISULINE, ALREADY JOINED THE
>7400 Tuebingen                  |   FIRE BRIGADE
>Germany                         |
>*****************************************************************************


I was in HK three years ago. I don't know what prices are like in Germany, but compared to the UK, Hong Kong wasn't that cheap, especially once VAT and Duty was added on. In the end, I didn't bother. Also, I found the attitude of the shopkeepers was really strange, like they basically didn't give a shit if you bought anything or not, and they refused to haggle - this is the price, like it or not, and if you don't like it then tough.

My advice is to buy stuff in the USA, which is *seriously* cheaper than Europe. Use a credit card and you can even do it by mail order.
---


Regards,

Hugh.
------------------------------------------------------------------
I don't speak for Xerox, nor they for me.

Rank Xerox European Systems Centre, Welwyn Garden City, Herts., UK.
Mail to; Huge.wgc1@rx.xerox.com, whatever it says in the header.

Newsgroups: rec.scuba
From: craig@cattnts.canada.ncr.com (Craig Campbell)
Subject: Re:  Deep air record.
Organization: AT&T / NCR Canada Ltd., Toronto, Canada
Date: Wed, 30 Sep 1992 16:15:13 GMT


With regards to more information on an unnamed deep air diver in Florida
slammed in the latest NAUI Sources, it would seem that the diver being 
held up as a poor example is a fellow named Hal Watts (Thanks Elliot Dierksen).

It also seems that Hal no longer holds the record, and that the record is
actually held by Bret Gilliam (Thanks to Michael Parker and Greg Dawes).

What I am still looking for is some of the details of what Hal Watts did
in terms of preparation and execution of his record setting dive(s?).  The
goal here is to form an informed and intelligent followup to the article
in sources, which I found to be biased and short on facts. (Like the evil
deep diver's name.)

Keep those cards and letters coming!!! :-)

craig


P.S.  Info about:  40 fathom club
		:  What is actually on the walls of Hal's diveshop
			(Bragging?  or realistic accounts?)
		:  Experience/diving history?
		:  Hal's credentials.

I expect that Hal (I know nothing of him) must be a serious technical diver
in order to have performed this type of diving and lived.

c.c.
-- 
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: smckenzi01@cc.curtin.edu.au
Subject: Re: o-ring tool?
Organization: Curtin University of Technology
Date: Mon, 28 Sep 1992 09:09:27 GMT

david r coelho writes:
> A while ago I recall mention of a tool for removing O-rings from
> camera's, etc. I just recently bought a video case and am in need
> of just such a tool. Could someone in the know please tell me where
> I can purchase this tool. Ideally, with a phone number. Thanks much!!!

                         :--------------------:

        Having worked for a hydrostatic test station for a number of years,
my preferred tool has become a double ended dental probe. One end should be
shaped like an "oxbow", the other like the top half of a question mark (?).

        The tips should not be honed to perfect points but should taper to
be fine enough to get behind o-rings and lift them without scratching plastic
that they may be resting next to.  The finer the probes the better, the steel
should be springy but brittle if you force it (should be stainless).

	While you are tracking these down you might like to pick up some
dental mirrors at the same time...(really useful). (Yellow Pages = Phone No.).

      o,--------------,         .. .. .. .. .. .. .. .. .. .. ..
      ||      |     /          :   Matthew Hepburn Mckenzie     :
      ||      |   /            :   38/216 Cambridge Street      :
      ||      |   \            :   WEMBLEY  WA  6014            :
      ||      |     \          :   AUSTRALIA                    :
      |/--------------'        :           Ph. +61 9 382 4819   :
      |                         .. .. .. .. .. .. .. .. .. .. ..
      |
      |
   /~~~~~~\           PSImail: psi%050529452300070::SMCKENZI01
/\/\/\/\/\/\/\/\/\/\/ Internet: SMCKENZI01@cc.curtin.edu.au
                      Bitnet: SMCKENZI01%cc.curtin.edu.au@cunyvm.bitnet
                      UUCP  : uunet!munnari.oz!cc.curtin.edu.au!SMCKENZI01
From: gd@blublaze.sw.stratus.com (Greg Dawe)
Newsgroups: rec.scuba
Subject: Re: Bechaut Alladen
Date: 6 Oct 92 19:21:01 GMT
Distribution: na,local
Organization: Stratus Computer, Software Engineering

In article <BvpMG7.Kz8@scd.hp.com> dave@hpdstma.ptp.hp.com (Dave Waller) writes:
>All this discussion of strange behavior by computers when the battery is low

I doubt that there is a useable or reliable method of determining whether
or not a battery is "too low".  I've had computers/batteries which
did not tolerate cold New England waters, but which worked fine down in
Florida or Cozumel (both a Skinny Dipper and a Monitor2).  I suspect that
the batteries were either just not up to snuff, or that battery technology,
manufacturing technology, or QA have improved in the last couple of years.
I've been running two Monitor2's for almost two years now without any
problems that might be associated with low battery voltage.  In fact, given
their usage, I'm surprised that I haven't had to send them in for new
batteries yet (perhaps I should keep quiet and not "give myself a canary").

Has anyone else had similar problems with a dive computer in cold water?





-- 
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: Charlie_Gibbs@mindlink.bc.ca (Charlie Gibbs)
Newsgroups: rec.scuba
Subject: Re: Bechaut Alladen
Date: 7 Oct 92 04:42:28 GMT
Organization: MIND LINK! - British Columbia, Canada
Distribution: world

In article <BvpMG7.Kz8@scd.hp.com> dave@hpdstma.ptp.hp.com
(Dave Waller) writes:

>As such, when considering purchasing a dive computer I would recommend the
>Phoenix (Delphi follow-on); I'd hate to have a DataMax and have it decide
>in the middle of my ten day vacation to Truk that it was going to crap out
>due to a low battery, and that I couldn't even replace the battery if
>I wanted.
>
>The Delphi and the Phoenix give ample, clear warning that the battery is
>running out, giving plenty of time to change it. Given the price of a
>vacation to tropical destinations, the few hundred $$ saved by purchasing
>a DataMax Sport over a Phoenix begin to seem trivial.

     The Datamax Sport does have a low-battery warning.  I've only
had mine for a couple of months, but other owners tell me that it
gives plenty of advance warning - enough for that ten-day vacation.
Hopefully they're right.

Charlie_Gibbs@mindlink.bc.ca
"I'm cursed with hair from HELL!"  -- Night Court

Newsgroups: rec.scuba
From: story@sgi.com (David (Duis) Story)
Subject: Re: Divecomputers and temperature
Organization: Silicon Graphics, Inc.
Date: Fri, 2 Oct 92 17:00:16 GMT

In article <1992Sep30.112504.20994@alf.uib.no> IBORSET@bg1.hbg.hydro.no (BRSET IVAR ARNE) writes:
>
>[...] is there any reliable research that shows if there is a
>connection between temperature (water and surface) and RNT ?  

There has been research conducted that correlates temperature changes
and exercise during decompression with varying DCS rates.

That is, if you start the dive warm, and then get progressively
colder, you are at a higher risk for DCS because a warm body exchanges
gas faster than a cold body.  Since you were ongassing while warm and
offgassing while cold, you're more likely to surface with a
higher-than-expected N2 loading.

By the same reasoning, exercise at the beginning of the dive and not
at the end can lead to higher N2 loadings.  (Ignoring the possibility
of micronuclei formation from tribonucleation.)

>In case there is,
>does anyone know if any of the computers currenctly on the market take this
>into account when calculating bottom time in general, and bottom time for
>repeated dives in particcular ?

No.  However, there are a few which you can manually adjust during
your surface intervals.  The Suunto Solution's "altitude" adjustment
comes to mind.

Cheers,

David Story                        NAUI AI Z9588, PADI DM 43922, EMT
story@bent.wpd.sgi.com		  Every dive is a decompression dive.
Newsgroups: rec.scuba
From: cgc2646@usl.edu (Cech Claude G)
Subject: Re: How about the Oceanic Datamax?
Organization: University of Southwestern Louisiana
Date: Tue, 29 Sep 1992 00:54:49 GMT

In article <1992Sep28.190927.25823@mailer.cc.fsu.edu> mayne@cs.fsu.edu writes:
>     [commenting on someone else's stuff whose attribution I've lost...]
>
>>It scares me to see people getting certified and immediately getting a
>>computer and totally forgetting how tables work.
>
>It scares me to think of people like those involved is this incident
>doing deep diving and giving the sport a bad name.
>
>Bill Mayne
>
We had a posting much earlier about how many people (DMs included) at one
of the dive shows couldn't correctly figure a simple profile on their
preferred table.  Makes you wander what the correlation is between
computer use and ability to do a profile...

Cheers -
	Claude

Revolutionary slogan for a revolutionary agency (NED):  Let them eat fish.

Newsgroups: rec.scuba
From: beutel@chdasic.sps.mot.com (Jim Beutel)
Subject: Arizona Divers
Reply-To: beutel@chdasic.sps.mot.com
Organization: Motorola SPS ASIC, Chandler, AZ
Date: Tue, 29 Sep 1992 00:15:23 GMT

Hello,

Anybody out there live, work or travel through Arizona?
I am presently in Phoenix and am interested in selling
my equipment to finance my new love for skydiving...!

I have a single alum, Decor Pacer, Collar BC, all the 
extras. After moving here from Los Angeles, my diving 
has taken a far back seat to private pilots license and
skydiving.

Thanks,
Jim
Keywords:
From: story@sgi.com (David (Duis) Story)
Newsgroups: rec.scuba
Subject: Re: DPV info wanted
Date: 6 Oct 92 00:35:55 GMT
Organization: Silicon Graphics, Inc.

In article <11009@sun13.scri.fsu.edu> mayne@ds1.scri.fsu.edu (Bill Mayne) writes:
>In article <qj8iqf4@twilight.wpd.sgi.com> story@sgi.com (David (Duis) Story) writes:
>>
>>...I've found the Tekna and Dacor scooters give me much higher
>>speeds when I brace them between my legs and steer by twisting or
>>bending my upper body.  
>
>A mail inquiry may have bounced, so I'll risk embarrassment and ask
>where all the net.world can hear - If this is not a joke I'd be
>interested to hear the details of how you do this. It would be great
>to amaze my friends, even if the technique can't be used in caves.

No joke!  Really!  I got the idea one dive chasing sea lion pups, who
were far outdistancing me on a fresh battery.

>Unless you have some modification to the switch you must be somehow
>locking it in the on position (maybe using a rubber band on the
>trigger?) This might not be safe in a confined environment, even
>wearing a helmet. The technique would probably be fun when just
>playing around in open water. What would you do about a runaway
>scooter if you lost control while learning the technique?

Pray it doesn't ram you in your privates.  No seriously, just hold it
down below, and just use your hands to make sure you keep hold of it,
and to trigger the ignition.  In a slight crouch, your hands ought to
be able to reach your knees (or maybe I'm an ape).  Works for me.

Cheers,

Dave Story                        NAUI AI Z9588, PADI DM 43922, EMT
story@bent.wpd.sgi.com	              Better diving through drugs.
From: jacke@meaddata.com (Jack Eddington)
Subject: Re: Pheonix Dive Computer
Organization: Mead Data Central, Dayton OH
Date: Fri, 2 Oct 1992 17:21:51 GMT
Distribution: na

robbins@zonev.enet.dec.com (Jeff Robbins) writes:

>24>Has anyone replaced their Delphi for the new Phoenix? (that is
>what it's called, right?)  Or has anyone bought a Phoenix?
>If so, what do you think about it?  Is this unit any good?
>I don't have a Delphi, but until I heard about all the problems
>with it, I was planning on getting one.  Now, I'm wondering if
>I ought to consider the Phoenix or forget it and look at
>something completely different.

I recently traded my Skinny Dipper II and $259 for a Pheonix (a whole separate
story). I have used it once for two dives in a local Ohio quarry. I think its
a great computer. It gives me all the information I want in a very user
friendly, easily understood fashion. A minor inconvenience (not limited to 
the Pheonix but applicapble, probably, to all air-integrated computers) is 
that you need an air source to turn it on. So to review your dive log you must
be connected to an air tank. I have all my equipment except an air tank (I
don't really want to do a lot of local quarry diving). But that's not, to me,
sufficient cause to be negative about it.

I'm leaving next Wednesday (10/7) for 5 days of diving off Panama city so
will get a chance to better put it through its paces. If anything new about 
the Pheonix comes up, I'll post it.

If you were interested in the Delphi, I'd suggest you get the Pheonix. It is
supposedly only a minor upgrade to the Delphi, but it will come with a 
warranty. The Delphi will not. If anything goes wrong with the Delphi, your 
only option will be to trade it in for a Pheonix for $259 (assuming this deal
is still in place).

-- 
Jack Eddington -- jacke@meaddata.com  -- uunet!meaddata!jacke
From: sjmcdona@socs.uts.edu.au (89458622 s j mcdonald)
Newsgroups: rec.scuba
Subject: Re: Aladin Pro problem
Date: 1 Oct 92 00:01:49 GMT
Organization: Computing Sciences, Uni of Technology, Sydney.

gregr@joyce.cs.su.oz.au (Greg Ryan) writes:

>Yesterday I pulled out my Aladin Pro to go for a dive to find it
>was already in the middle of one.  Some time since I packed it away
>a fortnight ago it started a dive with a 65.3m maximum depth, and it
>is now at 3.2m  Given that the dive timer has obviously clocked around
>a few times this was probably a wise deco stop.  When I put it in the
>water it registers depth changes correctly, but is seems to have lost
>its idea of zero.  It goes in for a repair this morning, but has anyone
>on the net had a similar problem with an Aladin Pro?

	>			Greg Ryan	gregr@cs.su.oz.au

	In July of this year I was in the Solomon Islands and had
	a similar problem. 

	After the first dive of the morning our boat (the Bilikiki)
	change dive sites. When I returned to check out my gear I
	noticed that my computer was in altitude mode.

	I decided to abondon the next couple of dives and continued
	on tables for the remainder of my holiday.

	Every couple of days I looked in on my computer to see how
	it was going. Some times it was diving, and other times
	flying. Who says computers aren't value for money.

	When I returned home, I noticed that it had clear the log
	and added a few dives of its own. On the way to the dive 
	shop it turned itself on again, and started to descend.

	I managed to log one more dive before I walk into the store.
	They informed me that the battery was low and it does
	that kind of thing "sometimes". Anyway, a new battery was
	put in, and everything seems fine again.....until the next
	time.

				Stuart McDonald sjmcdona@socs.uts.edu.au
From: 73467.2574@CompuServe.COM (Andy Schmidt)
Newsgroups: rec.scuba
Subject: Any info on 160cf tanks?
Date: 30 Sep 92 02:03:59 GMT

On Mon, 28 Sep 1992 17:21:40 GMT gd@blublaze.sw.stratus.com (Greg Dawe)
writes in his message <6801@transfer.stratus.com>

GD>A couple of weekends ago I was down on Long Island doing a bit of wreck diving.
GD>After the first day of diving, the boat captain, also an avid wreck diver,
GD>took us to a nearby shop to get air.  The shop's fill station was capable of
GD>dispensing/mixing various different diving gases.

Sounds like 'Enchanted Divers'. You didn't happen to dive with Howard,
did you?

GD>While waiting for my fill, I met a couple of divers who were getting 
GD>ready to dive the wreck of the USS Monitor (a Gary Gentile's expedition, 
GD>I believe).  When they manhandled their tanks over to the fill station I 
GD>couldn't believe the size.  They told me they were 160 cf, but with 
GD>overfills each tank could carry 200 cf!! 

These are Faber 20 liter tanks, manufactured in Italy after a German IWKA 
patent on the galvanized steel. They hold 20l (> 141 cu ft) at 200 bar (> 
2900 psi). If you give them a 'standard' 3300 psi OVERfill then you have
160 cu ft.  And, of course you can overfill them even further. Overall,
they make neat pony bottles, don't you agree?

Price is about $400.00 and they do NOT have DOT approval. However, now there
are 121 cu ft tanks available (at 2640 psi) WITH DOT approval. Also European
steel tanks and not THAT much smaller than the 20 liter monsters. 

Andy

Newsgroups: rec.scuba
From: pweissma@shearson.com (Philip Weissman)
Subject: Dive Rite Computer
Organization: Lehman Brothers
Date: Wed, 7 Oct 1992 01:11:13 GMT



Dive Rite hopes to have on the market at least one, and possibly more,
computers by next spring or early summer.  Different sources are
giving me slightly different information but what seems certain is
that the computers will do full decompression calculations and display
all the necessary information.  One of the computers will be
adjustable for nitrox.  Far less certain is that there will be a
computer which is adjustable for mixed gas (trimix and heliox) diving.
Whether or not these computers can correctly calculate for mid-dive gas
switches, such as using a 50% O^2 nitrox mix for decompression, is not
know to me.  Wholesale cost is said to be about $550 which would put
the retail price at about $1000.  That's all that I've been able to
find out so far.  I'll post any additional information I hear at the
NAUI ICUE conference this weekend.

Philip Weissman

Newsgroups: rec.scuba
From: keulen@possum.csu.murdoch.edu.au (Mike van Keulen)
Subject: Re: careers in diving...
Organization: Murdoch University
Date: 30 Sep 92 11:19:26 GMT

waldo@cybernet.cse.fau.edu (Todd J. Dicker) writes:

>How about:
>     (1)  The guy who gathers golfballs out of the water hazards at golf 
>courses;

Actually I _have_ thought about that one - is there any money to be made in it?
I thought possibly as a source of extra cash ... (especially with the demise of
my scholarship :-(   ).

Mike

--
***************************** Michael van Keulen *************************** 
* Snail: School of BES - Biology         e-mail: keulen@murdoch.edu.au     *
*        Murdoch University              phone:  ++ 61 (09) 360-2843 (work)*
*        Murdoch WA 6150  AUSTRALIA              ++ 61 (09) 417-3902 (home)*
*************************** "To Love is to _LIVE_!" ************************
Newsgroups: rec.scuba
From: adb@herboid.uucp (Anthony DeBoer)
Subject: Re: Wrist vs. Console computers ?
Organization: Linda's Dragon Memorial Society
Date: Sat, 03 Oct 1992 02:28:08 GMT

Simon Hamner <sch@getafix> writes:
>  My PADI instructor said the console mounted were a bit iffy since if the
>batteries went you lost your pressure measurement, or you had to have a
>standard pressure gauge fitted, which surely negates the reason for having
>a console mounted computer in the first place.

The main reason for having a console-mounted computer is to have all your
gauges in one place so you can scan them all in one glance.  The
disadvantages (and advantages) of pressure-integrated computers have been
covered elsewhere; if the battery fails you have no idea anymore how much
air you have, but with this setup working you have some projection of how
many minutes your air should last.  But that's by no means a "standard"
console-mounted computer; a lot of console-mounted computers have separate
mechanical pressure gauges.

My setup has a computer, a good old reliable standard mechanical pressure
gauge, and a compass in a console.  There's no connection between the
three other than all being mounted in the same hunk of rubber.  But I only
have to look in one place to see all my numbers; I don't have to check a
gauge here and a computer there and a compass in a third place.  It's the
same reason why a car has all the gauges in front of you in one cluster.
-- 
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?
Newsgroups: rec.scuba