pony bottle 6 or 13 cu. ft. ?
Jon C
"Kevin Falconer" <kpjfa...@aol.com> wrote in message
news:4d967234.03112...@posting.google.com...
> I ordered a 6 cu.ft. pony bottle, I had debated the 13 but it is much
> taller and about twice as heavy as the 13 cu.ft. I intend on using it
> when
> diving solo off my pontoon with someone on the boat. The spare air
> (3cu ft)
> claims 57 breathes at surface which of course would be less at depth.
> I figured
> 6 cu. ft. would provide 114 breathes at surface and certainly less at
> 60 or 80 ft. Since I'm not cave diving or tech diving all I would
> really demand of this
> 6 cu. ft. is to provide enough air to address a primary air supply
> problem and get me back to the surface. I also kinda like the feeling
> that if I had to shed my gear I would be able to carry just the small
> bottle and me to the surface,
> any comments or opinions would be appreciated.
>
> Kevin Falconer Fort Myers, FL
Fantastic idea to use Spare Air's marketing numbers to plan for a solo out
of air situation instead of doing 2 minutes of calculations yourself.
How are these numbers? For a 30 fpm ascent from 90 feet, with a 3 minute
safety stop at 15 feet, you're going to consume *14 cubic feet* of air,
assuming a not all that conservative 1 cf/min SAC for the panic situation.
That's also assuming an *immediate* ascent, not a minute of futzing around
trying to figure out the problem at depth before you ascend. With *1
minute* of messing around at 90 feet trying to solve the problem, your gas
usage for the situation rises from 14 cf to almost *18 cubic feet*.
Makes you feel pretty good about that 6 cf doesn't it?
Jon
Scuba
Ed
on TV is not true?.... no.....
If you dive deeper than 60 ft, I would return the 6' and get the 13....
If you dive sub 100 I would get the 19.... actually... I did... 12 years
ago....
Same discussion I had with my dive buddy several years back....
When you go to take a breath and there is no air (For whatever
reason)...you already need a breath so you have nearly no time to go
looking for a buddy who just turned a corner ahead of you. A 6 would
allow you to shoot to the surface without a problem but it does not give
you much time to do much else. I use a single 120 and a 19 pony...
kinda heavy but I can do 2 long back-to-back dives with nitrox and still
have a full pony and 500 PSI in the 120. Underwater it is not a bother.
One last item... I dive 34% O2 many times on deep wrecks where hard
bottom would put me over the 1.4 ATM O2 safety level (and the 1.6 ATM
Hard level) but the main decks are in the safe zone... BUT, If I had to
drop down to rescue someone/thing, I could go over to my pony and then
back to the Nitrox tanks as I surface.... I know I will be toast for 24
hours because my computer will be inaccurate. 19 gives you a little
more air for such an activity.
If all depends on your typical dive profile. (BTW... I also keep my pony
on board at all times even when fishing just in case I need to fix
something under the boat)
Scuba
to remove it, other times on the back, just in case.........there has never
been a "just in case", but I its a device incase someone or myself needs it.
I would never dive a dive that I think would need it, and I never add it
into my dive plan.
good diving.
Steve
"Ed" <e...@nospam.com> wrote in message news:3FBFFCF7...@nospam.com...
nos...@all.please.net
wrote:
> I ordered a 6 cu.ft. pony bottle, I had debated the 13 but it is much
> taller and about twice as heavy as the 13 cu.ft. I intend on using it
> when
> diving solo off my pontoon with someone on the boat. The spare air
> (3cu ft)
> claims 57 breathes at surface which of course would be less at depth.
> I figured
> 6 cu. ft. would provide 114 breathes at surface and certainly less at
> 60 or 80 ft. Since I'm not cave diving or tech diving all I would
> really demand of this
> 6 cu. ft. is to provide enough air to address a primary air supply
> problem and get me back to the surface. I also kinda like the feeling
> that if I had to shed my gear I would be able to carry just the small
> bottle and me to the surface,
> any comments or opinions would be appreciated.
A 13 is a little less than 500 psi in a standard AL 80.
Don't do the calculations at a fixed depth, do the calculations
during ascent to understand how long a bailout bottle will last. Do
the calculations with the breaths taken at a variety of depths to get
a feel for what is needed.
I dive with a 13, but a 6 is better than nothing.
Alan Street
Falconer <kpjfa...@aol.com> wrote:
€I ordered a 6 cu.ft. pony bottle, I had debated the 13 but it is much
€taller and about twice as heavy as the 13 cu.ft. I intend on using it
€when
€diving solo off my pontoon with someone on the boat. The spare air
€(3cu ft)
€claims 57 breathes at surface which of course would be less at depth.
€I figured
€6 cu. ft. would provide 114 breathes at surface and certainly less at
€60 or 80 ft. Since I'm not cave diving or tech diving all I would
€really demand of this
€6 cu. ft. is to provide enough air to address a primary air supply
€problem and get me back to the surface. I also kinda like the feeling
€that if I had to shed my gear I would be able to carry just the small
€bottle and me to the surface,
€any comments or opinions would be appreciated.
€
Kevin - lots of people are going to chime in about the futility of pony
bottles. I agree with these arguments, but since you asked specifically
about 6 ft3 vs 13 ft3 bottles, I'm going to try and put the argument
in a slightly different perspective (# of breaths is a meaningless
marketing term - define a "breath").
6 ft3 bottles are used by some rescue agencies for "surface" rescues -
i.e., getting a trapped driver out of a race boat. In these
circumstances, under real world stress, a 6 ft3 bottle provides 3 to 5
minutes of air at the surface (maximum depth during a boat rescue is 5
ft). While this is plenty of time for a surface rescue, it translates
into 1.5-2.5 minutes at 33 ft, 1.0-1.7 minutes (60 - 100 seconds) at 66
feet and 0.8-1.3 minutes (45-75 seconds) at 99 feet.
Are you comfortable relying on a backup scheme that provides this
margin of breathing time underwater?
Alan
Crownfield
>
> > How are these numbers? For a 30 fpm ascent from 90 feet, with a 3 minute
> > safety stop at 15 feet, you're going to consume *14 cubic feet* of air,
> > assuming a not all that conservative 1 cf/min SAC for the panic situation.
> > That's also assuming an *immediate* ascent, not a minute of futzing around
> > trying to figure out the problem at depth before you ascend. With *1
> > minute* of messing around at 90 feet trying to solve the problem, your gas
> > usage for the situation rises from 14 cf to almost *18 cubic feet*.
>
> for over 60 minutes in the 40 to 60 ft range, let's see, the math.....
> 80cf / 60m = 1.3 cubic ft per minute 6cf / 1.3m = 4.5 minutes, a little
> less than 5 minutes, not a lifetime but I dont plan on reading a book before
> my ascent. When one is faced with NO air and NO buddy, I'll take 4 1/2
> minutes over NO minutes !
and under stress your consumption rate will double or better.
divide your times by 2 or 3.
>
> Kevin Falconer Fort Myers, FL
>
> P.S. there would be no 30 fpm ascents or safety stops, it would be used
> in an emergency and I would rather be breathing on the way up than choking
> on saltwater.
Brian Nadwidny
>
> I have no intentions of going to 90 ft. solo. I've run an 80 cf
> for over 60 minutes in the 40 to 60 ft range, let's see, the math.....
> 80cf / 60m = 1.3 cubic ft per minute 6cf / 1.3m = 4.5 minutes, a little
> less than 5 minutes, not a lifetime but I dont plan on reading a book before
> my ascent. When one is faced with NO air and NO buddy, I'll take 4 1/2
> minutes over NO minutes !
Since you've already made up your mind on your diving practices then I
have to wonder "Why bother with any sort of bailout?" If you're diving
less then 90' and you can't surface from that on one breath, then WTF
are you doing in the water in the first place?
Brian
Edmonton, Alberta
Firewalker
asking about Spare Air? I hear they have these double tank beauties now...
Ian Cox
---
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Michael Wolf
news:4d967234.03112...@posting.google.com:
>> Since you've already made up your mind on your diving practices then I
>> have to wonder "Why bother with any sort of bailout?" If you're diving
>> less then 90' and you can't surface from that on one breath, then WTF
>> are you doing in the water in the first place?
>
>
> Brian, not only COULD I come up from 60 ft on one breath I could
> probably come up from 90 ft with one breath IF I had one deep breath.
> I look at the back up
> as something that may aid me in assisting someone else as well as well
> as giving me a completely redundant air source. No, it will not allow
> me to
> extract someone from a wreck, but tell me if your first stage locked
> up at say
> 60 ft. you would rather do an emergency ascent rather that grab your
> other second stage and do a somewhat controlled ascent. Brian, as in
> any other
> back up, I will probably never use it but in some situations I would
> feel better
> with a totally redundant 5 minute air supply. I said SOME situations,
> I would
> not use it on a simple reef dive with a buddy.
>
> Kevin Falconer Fort Myers, FL
>
If you're doing it because your first stage might lock up, then 2 valves
(be it Y or H) on your tank will do the job too.
--
Michael Wolf
------------
Cthulhu for President! Why settle for the lesser evil?
remove stopspam to reply
Fiona Watson
Kevin Falconer <kpjfa...@aol.com> wrote in message > breath and it's not
> . In either of these two
> situations I would prefer my backup over depending on a buddy, it's a
> personal choice. Also your figures seem very low with regards to the
> amount of air that
> a 6cf would provide. I'm hoping if it is ever needed it wont be a full
> blown
> panic but rather a switch over of air supplies in which case I would
> expect
> about 3-4 minutes at medium depths (40-80). If anyone is interested I
> will
> post actual breathing time at various depths once I'm set up. I of
> course
> cannot calculate a panicked breathing experience and hope I will never
> need
The whole point of a back-up is to prevent a gas emergency, in which case
there is no point in not having enough to get you out and back to the
surface - you can't calculate a panic-gas situation accurately, but you can
make some best guesses - at one time I used an air integrated computer, and
during that time there was a dive when it all went horribly wrong, until it
all came back under control, my breathing rate quadrupled, which from
anecdotal stuff would appear to be about average, and is now what I base my
bottom bail out on
Fi
Lalin
integrated computers that I have seen give you on a best case scenario the
"remaining time left", not psi or liters/min.
"Fiona Watson" <fiona....@zetnet.co.uk> wrote in message
news:3fc10ab5$0$8571$4c56...@master.news.zetnet.net...
James Connell
>>during that time there was a dive when it all went horribly wrong, until it
>>all came back under control, my breathing rate quadrupled, which from
>>anecdotal stuff would appear to be about average, and is now what I base my
>>bottom bail out on
>
>
> Fiona, thanks for your comments. In the case you decribed above a
> small
> reserve tank would definitely not have been enough. As I've said the
> choice comes down to size and what the reserve can do for me. Of
> course a bigger
> reserve is more air but it's also heavier and more cumbersome. As long
> as
> I realize what this size reserve can and can't do for me I'll be OK. I
> have
> no intentions of lugging around a reserve air supply large enough to
> handle
> the situation you described. I would hope if it was an OOA at depth my
> buddy
> would have been close enough to assist. I'll be honest with you I
> think I would rather be alone at 90 ft. and have my main supply fail
> with a 6 cf back-up than have it fail and my buddy is under a ledge 30
> ft away.....
>
> Kevin Falconer Fort Myers, FL
Kevin, all in all i'd go with the biggest bottle you *want* to carry.
this argument can go on forever - the only supply big enough for *all*
situations is a surface supply, and then you still have the problem of
that going bad :)
i recomend at least the 13, the six is just to dang small 9 but better
than water) and for me the absolute minimum is a 19.
Unita
You ment to say a "13ftcu" tank when properly filled to 3000psi will
hold 13cuft of air. This amount of air when placed into "80cuft" tank
will be equal to approximately 500 psi when all of other factors such
as temperature are held constant. This is otherwise known as Boyle's
Law which if you had a descent scuba instructure you would have
learned and understood this law.
> Don't do the calculations at a fixed depth, do the calculations
> during ascent to understand how long a bailout bottle will last. Do
> the calculations with the breaths taken at a variety of depths to get
> a feel for what is needed.
No, do the calculations as a fixed depth, the maximum depth you plan
to dive that is unless you perfer to cut it close and in which you
probably have a 100% chance of being wrong. Which means you probably
have a 100% chance of being injuried or worse, dead.
Doing it at fixed depth adds in a safety factor beyond what you may
think you may need. Depending on the criticalness of the equipment the
greater the redundancy or safety factor. There is no good way that to
determine how your breathing rate will change under extreme stress.
Anyone have any test data? Some say figure twice your normal rate. I
bet it is way different.
Here is why. Some happens at depth. Breathing increases to way beyond
normal. Switch to back up. Fixed problem. Time to go up. Breathing
decreases. Take a look at remaining gas, way lower than expected,
breathing goes back up. Do not have a real guage on your bottle so you
are in the dark. Try to relax but breathing is remaining the same.
Time to start looking for Neptune for help.
> I dive with a 13, but a 6 is better than nothing.
Nothng would be better since the pony is probably going to give a
false sense of security. I have a buddy with a 80cuft tank that works
pretty good as a back up.
My pony is used to get me to my buddy so that I do not arrive in a
complete panic.
Time to blow,
Allen
Alan Street
€> Are you comfortable relying on a backup scheme that provides this
€> margin of breathing time underwater?
€
€Alan, when it comes time to use it I dont think it's going to be
€a matter of "being comfortable".
I wasn't referring to comfort at the time of use. I was referring to
you being comfortable with a decision to rely on a backup scheme that
provides a very limited amount of time underwater
<snip>
€ Also your figures seem very low with regards to the
€amount of air that
€a 6cf would provide.
They might seem low, but they're not. A normal, reasonably experienced,
unstresssed diver in reasonably good shape has a SAC rate of about 0.5
ft3/min. At that rate, a 6 ft3 bottle will last about 12 minutes. Under
almost any stress, a divers SAC rate with increase by at least 2x, with
3x being reasonable (it could go up even higher). At a SAC rate of
1ft3/min, the bottle lasts about 6 minutes. At 1.5 ft3/min, it lasts 4
minutes (at the surface).
I'm hoping if it is ever needed it wont be a full
€blown
€panic but rather a switch over of air supplies in which case I would
€expect
€about 3-4 minutes at medium depths (40-80). If anyone is interested I
€will
€post actual breathing time at various depths once I'm set up.
That's a very naive assumption, and not one I would be comfortable
betting my life on.
Let me put it this way. If you're experienced enough that an OOA
situation wouldn't cause your SAC rate to increase by 2~3x, you
wouldn't be asking this question.
Also, any "test" you do at depth will be meaningless because you aren't
stressed. They will at least be practice, however ;-).
gdfI of
€course
€cannot calculate a panicked breathing experience and hope I will never
€need
€to.
€
Then why bother carrying a pony?
€Kevin Falconer Fort Myers, FL
Fiona Watson
Lalin <nehmads@REMOVETHIS!optonline.net> wrote in message
news:J_cwb.20964$Hb.76...@news4.srv.hcvlny.cv.net...
> Fi, how did you know that your air consumption quadrupled? All the air
> integrated computers that I have seen give you on a best case scenario the
> "remaining time left", not psi or liters/min.
You don't know at the time, there's a wee thingummy on the screen if you
download an Aladin air-x which tells you what your l/min are at any one time
as you move the cursor accros the screen
F
Abdul RUSFAWI (De-Ice Diver)
"Unita" <un...@my-deja.com> wrote in message
news:63148ea9.03112...@posting.google.com...
> Time to blow,
>
> Allen
Indeed.
Grumman-581
>nos...@all.please.net wrote in message
>pretty good as a back up.
Good, but not as good as carrying an AL80 for your 'pony'...
Charlie Hammond
kpjfa...@aol.com (Kevin Falconer) writes:
>I ordered a 6 cu.ft. pony bottle, I had debated the 13 but it is much
>taller and about twice as heavy as the 13 cu.ft. ...
If you are going to depend on a redundant air supply, don't depend on
"SpareAir" or a 6 CUFT pony. Even a 13 CUFT pony is marginal -- you
should be able to do an emergency ascent from any depth where 13CUFT
might work.
If you want to have enough air to (1) solve the problem that resulted
in the out-of-air situation, and then (2) to ascend safely to the surface
you should be thinking of 19 or 20 CUFT for dives in the 60-80 ft range
and at least 30 CUFT for up to 130ft.
Some people will probably point out that for many siutations a larger
air supply with rududant regulators on a H or Y valve my be preferable.
Or even doubles on a proper manifold.
--
Charlie Hammond -- Hewlett-Packard Company -- Ft Lauderdale FL USA
(hammond@not@peek.ssr.hp.com -- remove "@not" when replying)
All opinions expressed are my own and not necessarily my employer's.
Thomas Wong
might seem like a whole lota air while doing nothing, but have you ever
measure your air consumption while under physical or mental stress! Don't be
surprised if you sucked the tank dry in a couple of heart beats! Having a
redundant air source is a good thing, but it would ne wiser to avoid
situations that would require you to fall back on your backup air source in
the first place.
"Lalin" <nehmads@REMOVETHIS!optonline.net> wrote in message
news:J_cwb.20964$Hb.76...@news4.srv.hcvlny.cv.net...
nos...@all.please.net
> nos...@all.please.net wrote in message
> > A 13 is a little less than 500 psi in a standard AL 80.
>
> You ment to say a "13ftcu" tank when properly filled to 3000psi will
> hold 13cuft of air.
No, I meant to say what I said.
> This amount of air when placed into "80cuft" tank
> will be equal to approximately 500 psi when all of other factors such
> as temperature are held constant. This is otherwise known as Boyle's
> Law which if you had a descent scuba instructure you would have
> learned and understood this law.
Yes, I assumed the readership understood these details.
That's why I didn't bring them up.
> > Don't do the calculations at a fixed depth, do the calculations
> > during ascent to understand how long a bailout bottle will last. Do
> > the calculations with the breaths taken at a variety of depths to
get
> > a feel for what is needed.
>
> No, do the calculations as a fixed depth, the maximum depth you plan
> to dive that is unless you perfer to cut it close and in which you
> probably have a 100% chance of being wrong. Which means you probably
> have a 100% chance of being injuried or worse, dead.
500 psi in my 80 won't last as long at depth as it does during ascent.
Yet, as if by magic, I am able to make ascents on only 500 psi.
> Doing it at fixed depth adds in a safety factor beyond what you may
> think you may need. Depending on the criticalness of the equipment the
> greater the redundancy or safety factor. There is no good way that to
> determine how your breathing rate will change under extreme stress.
> Anyone have any test data? Some say figure twice your normal rate. I
> bet it is way different.
If you know you have enough air to surface, why panic? If you can do it
on the equivalent of a 13 (about 500 psi in your 80), then you can do on
a 13. The diver has every reason to remain calm with that knowledge.
> Here is why. Some happens at depth. Breathing increases to way beyond
> normal. Switch to back up. Fixed problem. Time to go up. Breathing
> decreases. Take a look at remaining gas, way lower than expected,
> breathing goes back up. Do not have a real guage on your bottle so you
> are in the dark. Try to relax but breathing is remaining the same.
> Time to start looking for Neptune for help.
My breathing rate doesn't go up when my 80 drops to 500 psi.
>
> > I dive with a 13, but a 6 is better than nothing.
>
> Nothng would be better since the pony is probably going to give a
> false sense of security.
Breathing air is better than breathing water. You aren't OOA if you
have air in either of your tanks.
If I do run completely out, I'd rather do so near the surface.
> I have a buddy with a 80cuft tank that works pretty good as a
> back up.
I don't always dive with a buddy; I'd prefer not to be tethered to
someone when I do. My buddy may accompany me to the surface
and render aid should it be needed. Experience with 500 psi
ascents tells me it won't.
> My pony is used to get me to my buddy so that I do not arrive in a
> complete panic.
I hope s/he'll have enough for the two of you (with you in your less
than complete panic). The two of you might have had enough air to
complete the ascent if you hadn't wasted your pony (at depth)
getting to h/is/er already depleted tank.
> Time to blow,
Typical; a rec.scuba discussion drifts to sex...
nos...@all.please.net
wrote:
> If your gonna carry a pony it better be bigger than a 6! A 6 cu. ft.
tank
> might seem like a whole lota air while doing nothing, but have you ever
> measure your air consumption while under physical or mental stress!
Don't be
> surprised if you sucked the tank dry in a couple of heart beats! Having
a
> redundant air source is a good thing, but it would ne wiser to avoid
> situations that would require you to fall back on your backup air
source in
> the first place.
>
I once did a safety stop on a 6 after using all but 250 psi of an
80 at depth. The final ascent began from about 70 feet.
I remember another safety stop on the 6 when I had to exit the water
"with at least one usable breath" in my main tank to conform to boat
rules.
Even a 6 is not completely useless.
Charlie Hammond
nos...@all.please.net writes:
>I once did a safety stop on a 6 after using all but 250 psi of an
>80 at depth. The final ascent began from about 70 feet.
>
>I remember another safety stop on the 6 when I had to exit the water
>"with at least one usable breath" in my main tank to conform to boat
>rules.
If you had kept quiet about these experiences, most people would
regaard you more hightly than they do now.
Both of these anecdotes are stupid, stupid, stupid.
And, yes, by "stupid" I mean seriously dangerous.
... er... um... or was this just a troll?
Lee Bell
> >I once did a safety stop on a 6 after using all but 250 psi of an
> >80 at depth. The final ascent began from about 70 feet.
I don't know that I'll call this one all that stupid, unless he actually had
to do the safety stop on the pony.
> >I remember another safety stop on the 6 when I had to exit the water
> >"with at least one usable breath" in my main tank to conform to boat
> >rules.
This one does sound a bit off the wall.
> If you had kept quiet about these experiences, most people would
> regaard you more hightly than they do now.
This sounds about right.
Lee
Charlie Hammond
"Lee Bell" <lee...@ix.remove.netcom.com> writes:
>"Charlie Hammond" wrote
[sombody wrote:]
>> >I once did a safety stop on a 6 after using all but 250 psi of an
>> >80 at depth. The final ascent began from about 70 feet.
>
>I don't know that I'll call this one all that stupid, unless he actually had
>to do the safety stop on the pony.
You don't think it's stupid to be at 70 ft with only 250 PSI?
It surely isn't the way I'd plan a dive.
rnf2
"Charlie Hammond" <hammond@not@peek.ssr.hp.com> wrote in message
news:7H5xb.9753$lm7...@news.cpqcorp.net...
> In article <DP3xb.20524$Rk5....@newsread1.news.atl.earthlink.net>,
> "Lee Bell" <lee...@ix.remove.netcom.com> writes:
> >"Charlie Hammond" wrote
> [sombody wrote:]
> >> >I once did a safety stop on a 6 after using all but 250 psi of an
> >> >80 at depth. The final ascent began from about 70 feet.
> >
> >I don't know that I'll call this one all that stupid, unless he actually
had
> >to do the safety stop on the pony.
>
> You don't think it's stupid to be at 70 ft with only 250 PSI?
> It surely isn't the way I'd plan a dive.
>
Whats that in Bar? I normally start a dive with between 200 and 250 bar in
the tank (Alu 80 is the hire norm) and turn the dive at 100 bar, looking to
surface after the safety with 50 bar climbing back on the boat.
rhys
Scuba
diving a 19.........
"rnf2" <rn...@NOSPAMwaikato.ac.nz> wrote in message
news:3fc5...@news.iconz.co.nz...
Rudy Benner
> the tank (Alu 80 is the hire norm) and turn the dive at 100 bar, looking
to
> surface after the safety with 50 bar climbing back on the boat.
>
> rhys
>
>
1 Bar = 14.5 psi. 3000 psi = 207 bar. 100 bar = 1450 psi.
I usually turn at around 1700-1800. I like to see about 400-500 as I climb
the ladder.
Alan Street
wrote:
€"Charlie Hammond" <hammond@not@peek.ssr.hp.com> wrote in message
€
About 17 Bar (and starting an ascent from 20 metres).
Grumman-581
> You don't think it's stupid to be at 70 ft with only 250 PSI?
What about the old J-valves that we used to use? They were set at 300 psi,
IIRC and we didn't tend to carry SPGs with us back then... I've been a lot
deeper than 70 ft when my J-valve informed me that it would be in my best
interest to expedite my trip to the surface...
Michael Wolf
Grumman-581 wrote:
Ours were set at 750 psi. But those were the times when you really did
'plan your dive and dive your plan'.
--
Michael Wolf
-----
Cthulhu For President.
Brian Nadwidny
>
> What about the old J-valves that we used to use? They were set at 300 psi,
> IIRC and we didn't tend to carry SPGs with us back then... I've been a lot
> deeper than 70 ft when my J-valve informed me that it would be in my best
> interest to expedite my trip to the surface...
With the benefit of hindsight, don't you think that was a pretty stupid
way of doing things?
Brian
Edmonton, Alberta
www.mossmanscubaventures.com
Dennis (Icarus)
> > They might seem low, but they're not. A normal, reasonably experienced,
> > unstresssed diver in reasonably good shape has a SAC rate of about 0.5
> > ft3/min. At that rate, a 6 ft3 bottle will last about 12 minutes. Under
> > almost any stress, a divers SAC rate with increase by at least 2x, with
> > 3x being reasonable (it could go up even higher). At a SAC rate of
> > 1ft3/min, the bottle lasts about 6 minutes. At 1.5 ft3/min, it lasts 4
> > minutes (at the surface).
>
> moderate exertion at 60ft - 80ft would be the most I would expect from the
> bottle, hope I never need it but after switching to it I would certainly
> know that there's not a lot of time to squander yet no need to panic.....
> If it's a problem I can't resolve anyway I'm no worse off with the extra
> reserve...
>
Once you get it, practice with it - intentionally increase breaking rate
while ascending.
Do this while you still have plenty left in your primary tank.
See how long it'll last from 60-80ft.
Dennis
> Kevin
Alan Street
€> They might seem low, but they're not. A normal, reasonably experienced,
€> unstresssed diver in reasonably good shape has a SAC rate of about 0.5
€> ft3/min. At that rate, a 6 ft3 bottle will last about 12 minutes. Under
€> almost any stress, a divers SAC rate with increase by at least 2x, with
€> 3x being reasonable (it could go up even higher). At a SAC rate of
€> 1ft3/min, the bottle lasts about 6 minutes. At 1.5 ft3/min, it lasts 4
€> minutes (at the surface).
€
€If I can get a good fill of 3300 to 3500, I would think 4-5 minutes under
€moderate exertion at 60ft - 80ft would be the most I would expect from the
€bottle, hope I never need it but after switching to it I would certainly
€know that there's not a lot of time to squander yet no need to panic.....
€If it's a problem I can't resolve anyway I'm no worse off with the extra
€reserve...
€
Kevin - it's your life. You're the one who has to live with the
consequences of your equipment choices. You've been given ample
information about the inadequacies of a 6ft3 "pony" by several people
here. But if you still want to rationalize it, nothing anyone says here
is going to change your mind. If you think it's a good idea, then go
ahead and dive with it.
chilly
"Alan Street" <alan@nonono_irsi.com> wrote in message
news:271120032131192928%alan@nonono_irsi.com...
> Kevin - it's your life. You're the one who has to live with the
> consequences of your equipment choices. You've been given ample
> information about the inadequacies of a 6ft3 "pony"
Hmm, 6ft3? I'd ride that pony.
(snip)
srsp...@hotmail.com
wrote:
Or anything else with a dick...
Sorry it slipped.
T
srsp...@hotmail.com
srsp...@hotmail.com
wrote:
<snip>
>
>Alan with all due respect (I think...) everything I read hear is
>opinions,
>there's rarely a consensus on anything unless it's a total no brainer.
>Since everyones' diving pratices here are different there's no way to
>say
>that a piece of equipment is not right for anyone. I think you'd
>change your mind real quick if your reg for example was tangled
>helplessly in wire
>leader at 90 feet, my guess is that if someone handed you a 6 cu. ft.
>bottle you'd lurch at it and be out of your gear in seconds, unless of
>course you would hold out for an occasional passerby with a 13.......
>
>Kevin
Bottom line it cost almost as much to set up independent doubles.
Bands / travel bands will run you about the same as a pony tamer.
Just buy another al 80. (almost the same price as a pony)
Then you have air to spare.
You can just change up one tank per dive if lets say the one that's
staying is 1/2 full (depending on your dive plans)
Does the rule of 1/2's or 1/3's have any meaning for you?
How about lucky streak?
If your diving near the end of sport limits (90ft +)
It’s time to pony up <grin> and lay out some cash.
As for the j valve, some of us were using spg before they became the
norm.
We were told that the extra hose if it broke would spell big trouble
which it would have until they started putting orifices in the hp
port.
We also use to ignore NDL's and PO2's as well.
Didn't make it right or smart.
I don't know where you dive but up here that type of behavior will get
you a warning.
The next time you could get kick out of the dive club or barred from
the charter.
Charters around here will generally give you the first one.
After that you better have a good excuse, which generally will not be
accepted.
Most operators / clubs do not recognize ponies as part of your usable
air.
So if you don't come up without the asked limit in your back gas your
in trouble.
Don't be offended but when I have a clown on board I don't ask his
finishing pressure I look for myself.
And I don't give second chances, I don't need the problems.
The two clubs I belong to don’t give second chances either, your back
for retraining or out.
Also they do not care about cu ft they want pressure 500 psi.
I’m a bit more lenient I believe the 500 psi on surface is just for
that.
Surface use.
Another thought.
Because if your pushing your gas supply to it's limit and your buddy
stays with you (lemming syndrome) Now you have a diver OOA what
reserves do you have?
The other point you might what to consider.
If your carrying a pony for spare air, it's like waving a red flag.
It tells every one your a newbie or ... worse.
There’s no room for it in today's diving for this type of behavior and
it’s strictly frowned on by all agencies.
But there is divers out there, that do not use:
SPG’s
Octo’s
BCD’s
But I can only say this.
They don’t get on the same charters I have been on over the years.
I have seen them turned away.
But today it would be rare around here to find one.
It’s even becoming the norm to carry a dive computer.
I have been on charter’s that provide them, not to say you have to
follow them but you have to take it.
Personally I don’t dive with newer divers that don’t carry a computer,
I use to carry an extra just for that purpose.
The nice thing about downloadable ones they can flap all they want,
the read out tells the story.
Which for an instructor wanting to limit his liability, works for me.
example: It was suggested in this ng by a dive shop employee that I
took a new diver (Basic 2yrs 30 dives) to 180 ft.
I have the logged dive on a Suunto (air integrated) and Aladdin pro.
The dive was 52 ft for 25 minutes.
Shows 5 minute safety stop at 15 ft.
Shows assent and decent with in 30 ft per minute.
Shows assent from 15 ft at less than 10 ft per minute.
My starting air was 3100 psi
My ending air was 1800 psi on Al 80, he was using the same type of
tank.
My sac rates calculated every 20 seconds showed no spikes (aka extra
effort)
Sac rate was around 0.5. in 2 knot current.
Pretty hard to argue the dive was stressful with those numbers
It pretty well kills the bs.
Now the computer he was wearing is downloadable if there was a problem
I would have down loaded it and mine.
Then filed a report with my agency to cover my ass if I was teaching,
which I wasn‘t.
I don’t teach civilians any more and I'm not insured to.
T
Crownfield
it happens to no class rifraf.
>
> T
Salty
Hmm. Could you and I flip a coin to see which of us might ride that pony first ??
Steve
Kevin Falconer wrote:
> Alan with all due respect (I think...) everything I read hear is
> opinions,
Opinions are exactly what you asked for when you started this thread.
> there's rarely a consensus on anything unless it's a total no brainer.
If you go back and reread thsi thread with an open mind I think you'll find that this
is one of the cases where there's a pretty good consensus. That could b4e an
indication that most people here think that this *is* one of the no-brainers.
> Since everyones' diving pratices here are different there's no way to
> say
> that a piece of equipment is not right for anyone.
That's true for which BC, reg, or wetsuit you use. It's true for what gas mix you use
on a given dive. The amount of gas you carry on a given dive is a different matter.
While there will certainly be variation in the gas consumption of different divers,
there will consistently be a large increase in the rate of consumption when the shit
hits the fan. The variables aren't so much about how much gas a diver with an
emergency will need for an ascent, but how they plan to deal with the emergency. If
the plan is to have a redundant air supply available, you then need to decide if that
air is just supposed to allow an all-out sprint for the surface, or if it should
allow for a slower ascent. If you know that 6 CF will satisfy your plans, why bother
asking what others think?
> I think you'd
> change your mind real quick if your reg for example was tangled
> helplessly in wire
> leader at 90 feet, my guess is that if someone handed you a 6 cu. ft.
> bottle you'd lurch at it and be out of your gear in seconds, unless of
> course you would hold out for an occasional passerby with a 13.......
If he had nothing he'd be happy for a half-empty Spare Air. If he *planned* to rely
on such a small source he'd be a fool. Once you decide you're going to go to the
trouble of carrying a pony bottle in the first place, it seems silly to worry much
about incremental increases in size between a 6 and a 13. BTW, did you know there are
also 9's?
--
Steve
The above can be construed as personal opinion in the absence of a reasonable
belief that it was intended as a statement of fact.
If you want a reply to reach me, remove the SPAMTRAP from the address.
Grumman-581
Wasn't that what Catherine the Great was rumored to have said?
<evil-grin>
Grumman-581
...
>Hmm. Could you and I flip a coin to see which of us might ride that pony first ??
Don't want "sloppy seconds"? <evil-grin>
Salty
You're very bad, Gru. I meant an actual pony. <evil grin too>
No...seriously, chilly lives in cowboy / cowgirl territory of Canada.
Calgary holds "Stampede" every year and so chilly would probably
insist on riding Western, I think. I'd have to flip the coin to see if
the saddle was Western or English for me, mind you if they started out
using an English saddle.
Btw... I saw the other post and heard that rumor about Catherine too.
Jack Farmer
Maybe it was too loose from over use?
chilly
> change your mind real quick if your reg for example was tangled
> helplessly in wire
> leader at 90 feet, my guess is that if someone handed you a 6 cu. ft.
> bottle you'd lurch at it and be out of your gear in seconds, unless of
> course you would hold out for an occasional passerby with a 13.......
If someone is that close to you, why wouldn't they give you their octo to
breath off of and help get you untangled at the same time? Or help you out
of your gear?
chilly
Rumored to have done. :^)
Grumman-581
...
>Rumored to have done. :^)
Yeah, I know it's an urban legend, but it was the best one-liner that
I could come up with at the time... Come to think of it, I can't come
up with a better one now either... Oh well...