Emergency Ascent, Pony Bottle vs Spare Air
Larry Charlot
>the low air signal, we could head for the anchor line together. After
>he begins a safe ascent up the anchor line, I could continue my dive
>with the reasurrance of my Spare Air being close in case of an
>equipment failure. Does this seem reasonable?
Cyril:
I have some reservations about the real-life usefulness of the Spare-Air.
It's so small, only a few cubic inches, that you only get maybe a couple more
minutes of breathing time at average scuba diving depths (50-60'). In an out
of air or equipment failure emergency, I feel that this isn't enough time to
make a safe ascent.
Because of the fact that you are experiencing an _emergency_ when out of air,
you need to take steps to avoid a potentially lethal (embolism) panic ascent.
Remember your training - STOP, BREATHE, THINK, _THEN_ ACT. The Spare Air
doesn't have enough capacity to allow you to take time to think out your
situation before beginning an emergency ascent.
Personally, for what the Spare Air costs, $299.00, I would rather invest
in a 20 or 30 cubic foot capacity pony bottle and basic regulator, like a TUSA
TR-200 or Beuchat VS-4. These are the "economy" models in their respective
brand names, but their quality is good and price is reasonable. With one of
these pony bottles, you can easily make a safe ascent from 100', plus a nice,
long safety stop of at least 3 or 4 minutes.
Yes, the pony bottle is heavier, bulkier, a little more expensive, and not as
"convienient" as a Spare Air, but in a real emergency, it can get you and your
buddy back home with plenty of safety margin, and time to think through the
emergency and therefore avoid panic.
As for your buddy, if your respective air consumption is that unbalanced, he
should ask for a larger cylinder if one is available on the boat. There are
steel tanks available from UD Divers, ScubaPro, and Sherwood that go up to 120
cubic feet capacity, yet are not much larger and heavier than an aluminum 80.
> Question #2: If a diver is at 80 FSW with 500 psi, could he make a
>slow, safe ascent without running out of air? Also, will there be
>enough air for a 3 min safety stop? Just curious as to the extreme
>involving low air and SAFE ascents. Thanks. Cyril
>MadM...@nospam.netcom.com
There are so many variables like water temperature, stress factors like low vis,
currents, rough wave action, etc., that it's difficult to answer your question
with a simple yes or no...Under ideal conditions, MAYBE you do it, but you would
probably get back to the boat with NO reserve (the tank on it's last gasp). At
80' you are using air almost 3 times faster than at the surface, so that 500 psi
is being depleted really fast. Bottom line, in my personal opinion, if you are
still at 80' with 500 psi left in a 80 cubic foot tank, you are right at the
borderline of a "low-on-air situation". Note that I just called this a
"situation", not an "emergency", but if ANYTHING were to go wrong, like your
buddy wander off at that moment or your high pressure hose develop a leak at the
guage swivel (I've seen this happen several times), your "situation" could
degenerate into an "emergency" real fast. Moral - don't "push" the limits,
always leave yourself some reserve when going deeper than you would feel
comfortable naking an ESA (emergency out of air swimming ascent).
This is really pushing it on an Aluminum 80. I rarely spend an entire dive at
80' as that gives such a short bottom time allowance. When I dive the deeper
reefs at Cozumel, say to 80 or 90 feet, I make it a point to step up to a
shallower level, say 60', when I get down to 1500 pounds, then begin my final
ascent to the safety stop at 800 pounds, unless I have reached the NDL time
limit before getting low on air. I would typically get to 15' with 600#, which
gives me plenty of air for an 8 or 9 minute safety stop. I have a personal rule
of thumb regarding safety stops: The safety stop should be 1 minute for each 10'
of your maximum depth, air supply permitting, and 3 minutes minimum. I can
usually make an 8 minute safety stop and get back to the boat with 200~300psi
remaining. It's very bad practice to drain a tank below this amount, you want a
least a couple hundred pounds to blow the water out of your regulator dust cap,
and to prevent any moisture from getting into the tank.
Just my $.02 worth..
Larry Charlot
CVann
>I have a personal rule
>of thumb regarding safety stops: The safety stop should be 1 minute for
each
>10'
>of your maximum depth, air supply permitting, and 3 minutes minimum.
I guess the longer the stop, the safer--but I've never heard this
particular "rule." Is this just something you came up w/ yourself or is it
recommended by some dive/safety/medical organizations?
Ron Lee
cv...@aol.com (CVann) wrote:
>>I have a personal rule
>>of thumb regarding safety stops: The safety stop should be 1 minute for
>each
>>10'
>>of your maximum depth, air supply permitting, and 3 minutes minimum.
>I guess the longer the stop, the safer--but I've never heard this
>particular "rule." Is this just something you came up w/ yourself or is it
>recommended by some dive/safety/medical organizations?
Sounds ok to me. However, I personally make it a point to make
multiple "safety stops" during the ascent. For example, on a 129.98'
dive, i would have an ascent that lasted easily 30 minutes. I would
stay a while at 80' or so, 60', 40', etc. The depths are not
scientifically determined nor are the durations. My point is that i
would prefer to outgas the nitrogen earlier before it has the chance
to form bubbles.
Ron Lee
Steve L
Ron Lee wrote:
>
> cv...@aol.com (CVann) wrote:
>
> >>I have a personal rule
> >>of thumb regarding safety stops: The safety stop should be 1 minute for
> >each
> >>10'
> >>of your maximum depth, air supply permitting, and 3 minutes minimum.
>
>
> Sounds ok to me. However, I personally make it a point to make
> multiple "safety stops" during the ascent. For example, on a 129.98'
> dive, i would have an ascent that lasted easily 30 minutes. I would
> stay a while at 80' or so, 60', 40', etc. The depths are not
> scientifically determined nor are the durations. My point is that i
> would prefer to outgas the nitrogen earlier before it has the chance
> to form bubbles.
>
> Ron Lee
Agree, but ...
Uh ... Ron he said *safety stop* not ascent - Larry I'm not following it
??? - if I dive to 130 for a few minutes - work my profile back up as a
multilevel dive [as Ron described] - then as you reccomend it, it's a 13
min. *safety stop* on *top* of the profile - qualified by "air supply
permitting" - this seems to be conservative in the extreme for
multilevel diving - and I'd use a pony bottle too or is this a case of
the pony bottle providing the air to do the *extreme* safety stop? I
dunno...
By the way 200 to 300 lbs at the surface can turn from situation to
emergency as well and pretty quickly with chop and current even in
Cozumel.
-Steve
*Vikings? There ain't no Vikings here. Jus us honest farmers. *
Charlie Scogin
> > >>of thumb regarding safety stops: The safety stop should be 1 minute for
> > >each
> > >>10'
> > >>of your maximum depth, air supply permitting, and 3 minutes minimum.
> >
> >
> > Sounds ok to me. However, I personally make it a point to make
> > multiple "safety stops" during the ascent. For example, on a 129.98'
> > dive, i would have an ascent that lasted easily 30 minutes. I would
> > stay a while at 80' or so, 60', 40', etc. The depths are not
> > scientifically determined nor are the durations. My point is that i
> > would prefer to outgas the nitrogen earlier before it has the chance
> > to form bubbles.
> >
> > Ron Lee
>
> Agree, but ...
> Uh ... Ron he said *safety stop* not ascent - Larry I'm not following it
> ??? - if I dive to 130 for a few minutes - work my profile back up as a
> multilevel dive [as Ron described] - then as you reccomend it, it's a 13
> min. *safety stop* on *top* of the profile - qualified by "air supply
> permitting" - this seems to be conservative in the extreme for
> multilevel diving - and I'd use a pony bottle too or is this a case of
> the pony bottle providing the air to do the *extreme* safety stop? I
> dunno...
>
> By the way 200 to 300 lbs at the surface can turn from situation to
> emergency as well and pretty quickly with chop and current even in
> Cozumel.
>
> -Steve
>
> *Vikings? There ain't no Vikings here. Jus us honest farmers. *
Steve,
He is talking about multilevel dives. Example - I go to 130 feet for
about 20 minutes, way beyond the square tables. I start my ascent, I
would not plan to be back to the surface for at least another 40
minutes. During that forty minutes I would spend some at 80', some at
60', some at 50', some at 40', some at 30', and some at 20', so on. By
the time I reach the surface I have had sufficent ascent time. I do not
need a "safety" stop, I already outgased all of the fast tissue
compartments. Of course I would follow my dive computer to make sure
that I have no soft ceilings.
H NED Huntzinger
Larry Charlot wrote:
>
> >the low air signal, we could head for the anchor line together. After
> >he begins a safe ascent up the anchor line, I could continue my dive
> >with the reasurrance of my Spare Air being close in case of an
> >equipment failure. Does this seem reasonable?
Yes and no. Air supply redundency is generally a good idea for when
you're going solo, but a Spare Air does not generally constitute a
'redundant air supply system' because of its extremely small capacity.
> Because of the fact that you are experiencing an _emergency_ when out of air,
> you need to take steps to avoid a potentially lethal (embolism) panic ascent...
Because of this stress, you MUST assume a higher air consumption rate
than what yours normally is...I'd figure 2x normal if you have a couple
of hundred dives of experiece or 3x-4x normal if you have less than
that.
> Personally, for what the Spare Air costs, $299.00, I would rather invest
> in a 20 or 30 cubic foot capacity pony bottle and basic regulator...
Absolutely, IMO, because of its small capacity, a Spare Air is only
"worth" around $50 tops. FWIW, if you've been thinking about upgrading
your primary reg and have been thinking about what to do with the old
one, a pony is the answer. This makes half of the cost of buying a pony
essentially "free" (because you were going to do it anyway).
> > Question #2: If a diver is at 80 FSW with 500 psi, could he make a
> >slow, safe ascent without running out of air? Also, will there be
> >enough air for a 3 min safety stop? Just curious as to the extreme
> >involving low air and SAFE ascents. Thanks. Cyril
See the table in the excerpt from the FAQ I've included below:
-hh
QUOTE FROM THE REC.SCUBA FAQ:
_________________________________________________________________
I'm thinking of getting a redundant breathing system,
in case I have a hose failure or run out of air, and can't find my
buddy. I've heard about something called "Spare Air", and also "Pony
Bottles". Should I buy one? Or is there something better?
First off, carrying a redundant breathing system is a good idea.
There
are a couple of important questions.
1. What are the [39]types of redundant systems, and how much do they
cost?
2. [40]How much air do you need to be safe in case of a problem?
3. [41]How likely are you to carry your redundant system with you
when you dive and vacation?
Types of redundant systems.
What sorts of redundant systems are there? First, by "redundant
system" I'm referring to a system that will continue to work no
matter
how catastrophic the failure of your main system. Thus, I won't
consider a Y valve a redundant system because of the fact that a
burst
disk could rupture or an O-ring could fail and exhaust your entire
air
supply, or, that because of an error or a bad gauge, you could
exhaust
your entire air supply. The three most frequently used redundant
systems are
1. the bailout bottle,
2. the pony bottle and
3. the independent twin tank.
Some British BCs have a small air bottle attached to the BC. With
proper training and practice, it is possible to use this air for
breathing. But since this isn't a straightforward regulator system,
we
won't discuss it here either.
The bailout bottle is available in sizes as small as 1.2 cu ft, and
as
large as 3 cu ft. The best known brand is "Spare Air". The bottle has
a regulator that must (for older models) be switched on before use.
Bailout bottles can cost between $200-$300. The ones sold at a
discount by mail order houses are typically smaller bottles of older
design.
The pony bottle is a smaller spare tank that is actually a small
standard scuba bottle, and attaches to a standard regulator. Many
people use an inexpensive regulator on their pony bottles. You also
need some sort of mounting system. Pony bottles can cost between
$250-$350 depending on the regulator selected, the size of the pony,
and the care you take while shopping. You can get a 13 cubic foot
pony
(in 2000 PSI and 3000 PSI models), a 17 cubic foot pony, a 30 cubic
foot pony, a 40 cubic foot pony, and some other sizes.
The independent twin tank is a second tank which is the same size as
your first tank, and which has its own regulator. Since the two tanks
fit into a single double tank bracket, they may look like a set of
doubles, but, in fact, they are two separate tanks. The independent
twin tank is a good option for certain specialty diving, like wreck
penetrations or extreme deep diving, but I won't discuss it further
here. Costs vary widely depending on how much the mounting costs, the
type of tank, and so forth.
How much air do you need to be safe?
The following chart was produced by Dave Waller, and presents a
picture that I feel is conservative. You should probably assume that,
in an emergency, you will be breathing at one of the higher breathing
rates. It also assumes a 60 fpm ascent rate, which is considered too
fast by many computer models and some training agencies. Therefore,
these numbers should be considered minimums, and any deviation from
these conditions would be likely to cause these numbers to increase.
#
Total consumption (ft^3) # Total consumption (ft^3)
without 15_ft Safety Stop [1] # with 15_ft Safety Stop [1,2]
#
Consumption rate (ft^3/min) # Consumption rate (ft^3/min)
Depth | 0.5 | 1.0 | 1.5 | 2.0 # 0.5 | 1.0 | 1.5 | 2.0
-----+------+-------+-------+-------#-------+-------+-------+------
60 | 1.66 | 3.32 | 4.98 | 6.64 # 2.75 | 5.50 | 8.25 | 11.00
80 | 2.33 | 4.66 | 6.99 | 9.32 # 3.42 | 6.84 | 10.27 | 13.69
100 | 3.10 | 6.21 | 9.31 | 12.41 # 4.19 | 8.39 | 12.58 | 16.78
130 | 4.45 | 8.90 | 13.36 | 17.81 # 5.54 | 11.08 | 16.63 | 22.17
150 | 5.48 | 10.95 | 16.43 | 21.91 # 6.57 | 13.13 | 19.70 | 26.27
200 | 8.48 | 16.96 | 25.45 | 33.93 # 9.57 | 19.14 | 28.72 | 38.29
Notes:
[1] Total consumption includes 30 seconds at indicated depth,
and
a 60_ft/min ascent rate.
[2] Assuming a 1/2 consumption rate during a 15_ft safety stop
for 3 minutes.
The numbers beyond sport diving depths are here only for reference,
and not to encourage you to dive those depths. Redundant air only
reduces one of the dangers you would face in diving to those depths.
The largest Spare Air holds just under 3 cubic feet. The smallest
available pony bottle holds 13 cubic feet. You can look at the chart,
estimate your surface consumption rate, try to estimate what it would
be in an emergency, and see where you fit in.
It is almost certain that if you were diving deep, you'd want more
air
than the chart shows, as you might need to make a longer
decompression
stop.
While some people have tested bailout bottle ascents from as deep as
100 fsw, it should be emphasized that these tests were not performed
under stressful conditions. Typically, they are already neutrally
buoyant, ready to ascend, and are consuming less air than they would
in an emergency. Referring to the above chart, you can see that this
would be possible for a diver who had a consumption rate of 1/2 cubic
foot per minute, and who left immediately upon switching to their
bailout bottle rather than taking time to get settled.
How likely are you to carry your pony?
People who prefer bailout bottles to pony bottles say that a pony
bottle is too cumbersome to transport and wear and in fact is not
carried, making it a useless boat decoration. Pony bottle proponents
who carry their pony bottles with them when they travel say that they
don't have a problem carrying them, and many wear them all of the
time
when they dive. They disagree that it is too hard/painful/time
consuming to dive with a pony bottle.
Opponents of bailout bottles believe that bailout bottles are useless
diver decorations, mainly because the bailout bottles do not contain
enough air for an emergency. They argue that from the time you switch
to the bailout bottle, you have only enough air to ascend directly to
the surface. You have no time to solve problems and little or no air
to make yourself positively buoyant. A final argument is that a
bailout bottle might actually give you a false sense of security, and
make you less safe than you might be without one.
Perhaps the final judgment should be made using the above chart, and
the depth to which you plan to dive. If $$/cubic foot is a
consideration for you, then you would probably prefer a pony bottle
to
a bailout bottle. Many people do all of their diving between 15-40
feet, and never dive deeper than 60 feet. These people would probably
find the largest bailout bottle useful. If you go deeper, or if you
might go deeper someday, consider a pony bottle of the appropriate
size.
There have been rare occasions (one reported, at the Hong Kong
airport
only) where people have been told that they simply can't bring their
scuba bottles on their flight, valves on or off, and have had to
abandon them at the airport. This would probably equally apply to
bailout bottles and pony bottles. You should plan on draining your
bottles of any type completely before flying to comply with airport
regulations, and you may have to remove the valves to prove to the
airline's satisfaction that the bottles are completely drained. It is
a violation of US FAA regulations to transport a bottle on an
airliner
pressurized to more that 41 PSIA. Airlines may have more stringent
regulations.
_________________________________________________________________
Steve L
Charlie Scogin wrote:
>
> Steve,
>
> He is talking about multilevel dives. Example - I go to 130 feet for
> about 20 minutes, way beyond the square tables. I start my ascent, I
> would not plan to be back to the surface for at least another 40
> minutes. During that forty minutes I would spend some at 80', some at
> 60', some at 50', some at 40', some at 30', and some at 20', so on. By
> the time I reach the surface I have had sufficent ascent time. I do not
> need a "safety" stop, I already outgased all of the fast tissue
> compartments. Of course I would follow my dive computer to make sure
> that I have no soft ceilings.
Charlie -
Got that was what Ron does - and I do the same - seemed to me though
Larry, in his original post, was saying that *even* for a multilevel
dive [by not making any distinctions about a multilevel dive profile]
that he would do 13 minutes *additional* at a safety stop, air
permitting, according to his rule of thumb for a 130 fsw dive - that's
what was confusing to me - why so conservative - as Larry didn't say he
*spread* the safety stop time out over the ascent [as both you, Ron and
I would likely do] but seemed to be saying that he took one minute for
every 10 feet of max depth - ok for a square dive but needless for a
multidive profile as Ron pointed out - and as I was trying to do in my
post by wondering if the justification for the pony bottle is an actual
need for air or the just the means for Larry to do extremely
conservative safety stops following his rule of thumb.
-Steve
MadMedic
H NED Huntzinger <{rm_to_reply}hum...@webspan.net> wrote:
>Larry Charlot wrote:
>>
>> >the low air signal, we could head for the anchor line together. After
>> >he begins a safe ascent up the anchor line, I could continue my dive
>> >with the reasurrance of my Spare Air being close in case of an
>> >equipment failure. Does this seem reasonable?
>Yes and no. Air supply redundency is generally a good idea for when
>you're going solo, but a Spare Air does not generally constitute a
>'redundant air supply system' because of its extremely small capacity.
Well, I wholeheartedly agree that the Spare Air would have been a
complete waste of money. I went with a 13 CF Al pony setup. I have
seen recommendations for larger pony's on this newsgroup, but I think
the 13 is enough for my type of diving. I am pretty good with air
consumption, and because I am small and in good shape (140 lbs. 5'8")
the 13 will probably suffice.
Ben Looi
Just my two cents worth...
Guess the whole issue of deep diving and stops(safety or planned) comes
down to fundamental gas management. The golden rule of "PLAN YOUR DIVE AND
DIVE YOUR PLAN" would suffice. True, safety stops have no scientific
premises, just a layman's conservative practise, just incase. Why 1
minute? why 2 minutes, why x minutes? A pony bottle is an EMERGENCY
bailout, and should not be part of your dive plan. The question then is
whether Spare Air has got enough air for an emergency or not. My view is a
definite "NO". what is 2 cubic ft when compared to 13 cubic feet? If you
are at a depth where you will need at least a few breaths to surface in an
emergency, a Spare Air bottle is not enough. Don't forget to factor in
stress and shock...you will breathe harder if you are in a panic,
out-of-air situation.
For those who want to do planned stops, use a Stage bottle. :)
ForSPBurke
In article <33EEE8...@webspan.net>, H NED Huntzinger
<{rm_to_reply}hum...@webspan.net> writes:
>> Personally, for what the Spare Air costs, $299.00, I would rather
invest
>> in a 20 or 30 cubic foot capacity pony bottle and basic regulator...
>
>Absolutely, IMO, because of its small capacity, a Spare Air is only
>"worth" around $50 tops. FWIW, if you've been thinking about upgrading
>your primary reg and have been thinking about what to do with the old
>one, a pony is the answer. This makes half of the cost of buying a pony
>essentially "free" (because you were going to do it anyway).
>
>
Point of caution
Too many people seem to feel that the "old" (read that "improperly
maintained") reqykator is fine for the pony. NOT. Remmember, the pony
will generally be used whenthat totally redundant gas supply is necessary.
Thereforee, it is an essential part of that redundancy that the regulator
works!! Should be in at least as good a condition as your "primary".
Some feel even better because it is infrequently used, often abused, and
tends to be checked less frequently.
Steve Burke
for...@aol.com
H Huntzinger
ForSPBurke wrote:
>
> Point of caution
> Too many people seem to feel that the "old" (read that "improperly
> maintained") reqykator is fine for the pony. NOT. Remmember, the pony
> will generally be used whenthat totally redundant gas supply is necessary.
> Thereforee, it is an essential part of that redundancy that the regulator
> works!! Should be in at least as good a condition as your "primary".
> Some feel even better because it is infrequently used, often abused, and
> tends to be checked less frequently.
A good point. I did NOT intend to infer that "old" meant that in any
way
that it was unservicable, unsafe or unmaintained.
FWIW, I do personally feel that it is perfectly acceptable if the pony's
regulator is of lower nominal performance, as many times you'll want to
have a higher breathing resistance on your pony or octopus regulator
anyway
(to prevent freeflows), so this is not really a penalty...and in some
ways
it can actually be advantageous: simpler designs are more robust and
reliable and if your reg is a non-balanced design, this will give you
a "low air" warning which offsets the general absence of an SPG on the
pony.
-hh
jf mezei
Charlie Scogin wrote:
> He is talking about multilevel dives. Example - I go to 130 feet for
> about 20 minutes, way beyond the square tables. I start my ascent, I
> would not plan to be back to the surface for at least another 40
> minutes.
If you go that deep (40m), it means that you have at least advanced
diver certification or equivalent experience. And such experience should
have given
you a pretty good idea of your air consumption, what sort of times your
tank
will allow you down there as well as what the tables/wheel/computer will
allow you.
I do not know what sort of tanks you have, but 20 minutes at 40m, you'd
start to be pretty low on air already, and taking 40 minutes to ascend ?
Definitely not recreational diving stuff.
jf mezei
One thing to remember. From 10m to surface, you can ascend fairly
"safely" on only one breath of air, constantly exhaling. Anyone having
done the basic Open Water course should have tried this and be confident
it is possible to do.
Running out of air is like cancer. If you detect early, your chances are
better.
If you are careless enough to not notice that you are running low on
air, and if you are careless enough not to stay close to your buddy and
regularly check his SPG, then I am sorry to say that a spare air or pony
will not compensate for your lack of safety and/or training.
I do not consider myself an expert in diving, but within 1-2 dives with
a particular buddy, I generally get a VERY good gauge of his air
consumption versus mine. Needless to say that I do check my SPG
regularly and I can usually know very well what the spg on the buddy
will read.
If you *and* your buddy allows yourself to run out of air, then neither
of you should be diving. I consider it a responsability of a buddy to
check my air, and mine to check his/her/its air.
As far as massive failures causing instant stop of your air supply,
I agree that having a separate source of air (pony or spare air) may
enable you to breathe at least until you reach your buddy and start
sharing his air supply. Either way, 50 bars should always be enough
for both of you to ascend from 30m to the surface safely. If you run out
of air at the safety stop at 5m, you'll need less than a breath to reach
the surface, constantly exhaling, of course.
H NED Huntzinger
MadMedic wrote:
>
> Well, I wholeheartedly agree that the Spare Air would have been a
> complete waste of money. I went with a 13 CF Al pony setup. I have
> seen recommendations for larger pony's on this newsgroup, but I think
> the 13 is enough for my type of diving.
The size partly depends on depth, SAC, etc, but I think that a lot of
the recommendations for going "bigger" is because:
a) It usually doesn't cost anything more (or much)
b) Most applictions are for local diving, so the extra size/weight
isn't really an issue.
c) Conditions can warrant it (especially generic "local coldwater"
diving)
Personally, I feel that where a 13 pony may be just fine for vacation
diving, a 30 pony would be a better choice for local diving, due to the
combination of the above factors.
Hopefully, this explains some of the reason behind the recommendations.
-hh
Lee Bell
Ben Looi wrote:
>
> The question then is whether Spare Air has got enough air for an
> emergency or not. My view is a definite "NO". what is 2 cubic ft when
> compared to 13 cubic feet? If you are at a depth where you will need
> at least a few breaths to surface in an emergency, a Spare Air bottle
> is not enough. Don't forget to factor in stress and shock...you will
> breathe harder if you are in a panic, out-of-air situation.
Your conclusion may or may not be accurate for you, but your statements
don't address the issue. Whether a spare air compares to a 13 cubic
foot tank has nothing to do with whether the spare air is enough or not.
Shock and semi-panic may also be factors, but the conlcusion remains
unsupported. What you probably should be saying is that your preference
is the pony rather than the spare air because it provides a greater
margin of safety.
Given the fact that an overwhelming majority of divers have no redundant
air supply at all (except perhaps a buddy), a spare air is certainly
better that what is available to the average diver.
Personally, I can and have ascended from the depths I normally dive to
with no redundant air supply (128 feet) without any signs of DCS I could
detect. I don't have a spare air or a pony and probably won't unless I
can get a good deal on a couple of spare airs. Even then, the SA will
be primarily for the purpose of providing time to get to my buddy or
visa versa and only secondarily for an emergency ascent. For me, a pony
is more bulk and more hassel than it is worth. Others have a greater
need and still more divers feel the need for the extra precaution. Good
for them, its their choice.
Lee
Jammer
In article <33F0E5...@videotron.ca>, "[non-spam]jfmezei"@videotron.ca wrote:
€> If you are careless enough to not notice that you are running low on
€> air, and if you are careless enough not to stay close to your buddy and
€> regularly check his SPG, then I am sorry to say that a spare air or pony
€> will not compensate for your lack of safety and/or training.
On the other hand, if you touch my SPG, that will also place you beyond help.
€> If you *and* your buddy allows yourself to run out of air, then neither
€> of you should be diving. I consider it a responsability of a buddy to
€> check my air, and mine to check his/her/its air.
Your attitude is a fools, but fortunately you endanger only yourself.
If you run out of air, under any circumstances, Darwin will not even
consider holding your buddy responsible.
This is as it should be, and it warms the coldest cockles of my heart to
think how far ahead of me in line you are for that final dive.
€> As far as massive failures causing instant stop of your air supply,
€> I agree that having a separate source of air (pony or spare air) may
€> enable you to breathe at least until you reach your buddy and start
€> sharing his air supply.
Yes, I agree. You, personally, should always rely on a Spare Air.
------
"Huh?"
-Jammer, 1992
------
Benthic HI
For a recreational diver, doing no-decompression dives, and not pushing
the limits (ie, not diving up to the no-deco limits), a spare air could
allow an individual to get to the surface in an out-of-air emergency, in
the event that you have the larger one (2.7 cubic feet). I would not rely
on one for overhead environments.
The pony bottle argument, in the above scenario, adds bulk and drag to
one's setup. I am a minimalist, and believe that the minimum amount of
equipment for a given situation should be worn. Too many divers overdo
the equipment for a given dive (even course directors who wear doubles for
a 45- minute 100-foot dive). The result is increased effort, increased
drag, and increased air consumption. Rec divers without a pony bottle or
second tank should plan all dives as no deco dives.
Charlie Hammond
In article <5sr378$3...@dfw-ixnews9.ix.netcom.com>,
Lee Bell <"leebell@"@ix.netcom.com> writes:
>Given the fact that an overwhelming majority of divers have no redundant
>air supply at all (except perhaps a buddy), a spare air is certainly
>better that what is available to the average diver.
Lee, the logic you use to reach the above conclusion is irrefutable.
Unfortunately, not all recreationsl divers use logic correctly, at least
not all the time.
Consider the diver who does not have your enviable ability to ascend from
as deep as 128 feet with no redundant air supply. If such a diver illogically
and incorrectly believes that a SpareAir will allow a normal ascent from that
depth, then there is at least a possibility that he/she will dive that deep
WITHOUT the proper training/equipment/skill/planning etc. Without the SpareAir
this diver would be more likely to plan a dive within his/her limits.
So, is this diver better off with a spare air than without?
--
Charlie Hammond -- Digital Equipment Corporation -- Nashua NH USA
(ham...@peek.enet.dec.com -- remove "@not" when replying)
All opinions expressed are my own and do not necessarily reflect
my employer's position.
Charlie Scogin
Ben,
I agree with you totally. GAS MANAGEMENT. that is the ticket. i have
never ever even come close to being out of air with a 80 cu. ft. tank -
never. i plan my dive and dive my plan. i seldom even breathe them down
to 500 psi. i dive with the "girl" tanks, i think the are 50 cu. ft. but
i may be wrong, and can get 60 minutes out of it easy with just about
any non-deco profile.
Ron Lee
hammond@not@peek.enet.dec.com (Charlie Hammond) wrote:
>Consider the diver who does not have your enviable ability to ascend from
>as deep as 128 feet with no redundant air supply. If such a diver illogically
>and incorrectly believes that a SpareAir will allow a normal ascent from that
>depth, then there is at least a possibility that he/she will dive that deep
>WITHOUT the proper training/equipment/skill/planning etc. Without the SpareAir
>this diver would be more likely to plan a dive within his/her limits.
>So, is this diver better off with a spare air than without?
> Charlie Hammond -- Digital Equipment Corporation -- Nashua NH USA
Charlie, you apparently assume that the diver will not have a buddy
(ies) around for alternate air. If that person is diving solo to
those depths with a SpareAir for redundant air, they are taking on a
higher risk than I would accept.
My use of a spare air at that depth is only to get to another diver.
Even at that, I now know that the spare air is basically worthless at
that depth. My question, yet to be finalized, is whether a 19 or 30
cu ft pony will work for ME in a lost buddy/sudden loss of air
situation at 140-150' depth.
Ron Lee
Fishbre396
In article <5st2lt$tpr$1...@nntpd.lkg.dec.com>, hammond@not@peek.enet.dec.com
(Charlie Hammond) writes:
>>Given the fact that an overwhelming majority of divers have no redundant
>>air supply at all (except perhaps a buddy), a spare air is certainly
>>better that what is available to the average diver.
WRONG!!! Most NE divers, yes, those who dive COLD water, that has poor
VIZ, do use redundent air supplies. NO, they do not use "SPARE AIR" Yes,
they usually have a pony bottle. WHY?? SPARE AIR is usually about 12
breaths . . . Pony is much more air than that!!
>
>Lee, the logic you use to reach the above conclusion is irrefutable.
>Unfortunately, not all recreationsl divers use logic correctly, at least
>not all the time.
Logic??? What logic is needed here? It's not logic, it's fact.
>
>
J Shepherd
>Given the fact that an overwhelming majority of divers have no redundant
>air supply at all (except perhaps a buddy), a spare air is certainly
>better that what is available to the average diver.
I disagree. There is an absolute criteria - is it enough. If the
answer is no, then it is not 'better than nothing'. Indeed, by
suggesting to the the diver that he now has a 'redundant air supply' it
promotes bad buddy diving practice.
In *good* buddy diving practice, you have rapid access to an
80cuft tank, which contains at least 50bar (c.20cuft). Anything else is
bad buddy diving practice, which a spare air can not excuse,
>be primarily for the purpose of providing time to get to my buddy or
>visa versa and only secondarily for an emergency ascent. For me, a pony
You are using the spare air to expand the flexibility of the
buddy system; not the same thing as a redundant air supply, but a more
reasonable use.
Jason
Perry West
Mixmaster (mixm...@remail.obscura.com) wrote:
: In any case, some agencies advise that you keep your regulator in your mouth
: during an emergency ascent so that you might benefit from the expanding air
: in the hose. Dispensing with the above piffle (+), how can a Spare Air not
: be an improvement over expanding air in the hose?
The reason for keeping something (regulator, spare air, etc.) in your
mouth while doing an emergency swimming ascent is not primarily because
you will get a breath or two during the ascent (which as you point out,
you will), but because a diver doing an emergency swimming ascent might
have an uncontrollable urge to breathe. Having the regulator in the
mouth will give at most nothing. With nothing in the mouth, the diver
will most probably asperate water during this reflex and drown.
Regarding the spare air; I agree they are insufficient when used on
deeper dives. Was buddied up with a person on one trip who had a spare
air as the redundant source (no octo). It was a very nervous time for
me. I resolved if I ran out of air 1) to physically attach myself to
this person, 2) to use the spare air until it was depleted and then throw
it away, and 3) to give this person impromptu instruction in buddy
breathing (i.e., if they want their regulator back, they needed to be a
quick learner). I am happy to say I never had to put my plan into action.
Regards,
Perry
Lee Bell
Charlie Hammond wrote:
> Consider the diver who does not have your enviable ability to ascend
> from as deep as 128 feet with no redundant air supply. If such a
> diver illogically and incorrectly believes that a SpareAir will allow
> a normal ascent from that depth, then there is at least a possibility
> that he/she will dive that deep WITHOUT the proper raining, equipment,
> skill, planning etc. Without the SpareAir this diver would be more
> likely to plan a dive within his/her limits. So, is this diver better
> off with a spare air than without?
If the diver lets the spare air put him in that position, he was
obviously better off without it. Once he's there, however, he's still
better off with the spare air than without it. Either way, he's in
trouble. The same diver is just as likely to include his redundant pony
in his dive/air management plan with much the same results.
The situation you described says much more about the diver than the
spare air, pony or any other equipment. He made more than one
fundamental error which you've joined the rest of us in preaching
against. He clearly did not understand his limits and/or dive within
them. I believe this is the number one cause of diving accidents, way
ahead of anything else. He also misunderstood and/or misused his
redundant air source by considering it in his dive/air management plan,
something a diver who could competently do this dive would never do.
I choose to put the blame on the diver, not the equipment.
The worst thing about the spare air is that the company that makes them
thinks a 7 cubic foot redundant air supply with a substandard regulator
is worth more than a larger pony with a regulator good enough to be used
as a primary.
Lee
Lee Bell
Perry West wrote:
> The reason for keeping something (regulator, spare air, etc.) in your
> mouth while doing an emergency swimming ascent is not primarily
> because you will get a breath or two during the ascent (which as you
> point out, you will) . . .
Spoken like someone who has not been there and done that (no offense
meant). Trust me, no matter what the agency's reason is, MY REASON was
because of the air I got on the way up combined with the fact that it
simply did not occur to me to take the regulator out of my mouth. I had
other things to worry about at the time.
> Regarding the spare air; I agree they are insufficient when used on
> deeper dives. Was buddied up with a person on one trip who had a
> spare air as the redundant source (no octo). It was a very nervous
> time for me.
A spare air certainly is insufficient if used this way. You had good
reason for being nervous. Unless this was a relatively shallow dive,
the situation sounds like a good candidate for an aborted dive.
> I resolved if I ran out of air 1) to physically attach myself to
> this person, 2) to use the spare air until it was depleted and then
> throw it away, and 3) to give this person impromptu instruction in
> buddy breathing (i.e., if they want their regulator back, they needed
> to be a quick learner).
Sounds like a plan to me. Hopefully, a diver who has no octo already
knows how to buddy breathe. I learned to dive without an octopus and
was trained in buddy breathing. Needless to say, I don't agree with any
agency that suggests a free ascent is better than buddy breathing.
These days I have an octo just like everyone else, but I still consider
buddy breathing to be a useful skill.
Lee
Lee Bell
J Shepherd wrote:
> I disagree. There is an absolute criteria - is it enough. If the
> answer is no, then it is not 'better than nothing'. Indeed, by
> suggesting to the the diver that he now has a 'redundant air supply'
> it promotes bad buddy diving practice.
Sorry Jason, but you're wrong.
1. There is no absolute criteria. If you are diving with a buddy,
how much redundant air do you need? No matter what you answer,
it's not enough for any and all situations which can occur. You
set your risk limits and live or die by them. I'll do the same.
2. Some air is always better than no air, ALWAYS.
3. Having a spare air as a redundant air supply does not "promote" bad
diving practices of any type. Neither does having a pony, doubles,
or other emergency equipment. Only bad divers promote bad diving.
4. Neither you nor I are qualified to define bad diving practices in
this context (buddy practices). Some people, inclding me, find
the risk acceptable under certain cirumstances.
Lee
jf mezei
The feeling I get about Spare Air is that it is perhaps useful to let
you get to your buddy if your dive profile calls for you and your buddy
to be separated at times.
So I would consider such a device only as something which eases the
transition between your own air and your buddy's air supply.
Mixmaster
>hammond@not@peek.enet.dec.com (Charlie Hammond) wrote:
>
>>Consider the diver who does not have your enviable ability to ascend from
>>as deep as 128 feet with no redundant air supply. If such a diver illogically
>>and incorrectly believes that a SpareAir will allow a normal ascent from that
>>depth, then there is at least a possibility that he/she will dive that deep
>>WITHOUT the proper training/equipment/skill/planning etc. Without the SpareAir
>>this diver would be more likely to plan a dive within his/her limits.
>
>>So, is this diver better off with a spare air than without?
>
>> Charlie Hammond -- Digital Equipment Corporation -- Nashua NH USA
This argument is as specious as saying that drivers of cars equipped with
airbags will take more chances than those who drive cars not so equipped.
It's right up there with "Motorcycle riders who wear helmets take more risks
than those who do not." +
Bullshit, poppycock, nonsense, balderdash, blather, bunkum, claptrap!
>
>Charlie, you apparently assume that the diver will not have a buddy
>(ies) around for alternate air. If that person is diving solo to
>those depths with a SpareAir for redundant air, they are taking on a
>higher risk than I would accept.
>
>My use of a spare air at that depth is only to get to another diver.
>Even at that, I now know that the spare air is basically worthless at
>that depth. My question, yet to be finalized, is whether a 19 or 30
>cu ft pony will work for ME in a lost buddy/sudden loss of air
>situation at 140-150' depth.
>
>Ron Lee
>
In any case, some agencies advise that you keep your regulator in your mouth
JD TURNER
Baker Tom (bake...@aol.com) wrote:
: Having just started looking at this newsgroup, I thought this
: particular topic would be a little heated. Having been diving for over 20
: years (yes, I am a dinosaur and so is my equipment) and having taught
: diving for 10 years during that time, I have watched as the diving
: community has slowly drifted away from preaching buddy breathing towards
: having a redundant air supply, wether that be a pony bottle, octopus, or
: spare air. In my experience, all of these are good choices, depending on
: the circumstances and the divers involved. There is no one solution that
: students!!). I am open to different suggestions or even improvements on
: what I do. Just don't sling mud.
Nope, seems like you got pretty much everything covered, and I tend to agree
with you on everything.
There have been times that I have regretted taking my pony bottle with me
(you know those long walks to the shore), but I think that keeping my
kit as constant as possible is the best thing, not only for me, but
for my regular buddy (she knows my kit layout as well as she knows her own,
and vice-versa) especially for some of the diving we do.
Jon
:
: Tom P.
Baker Tom
Having just started looking at this newsgroup, I thought this
particular topic would be a little heated. Having been diving for over 20
years (yes, I am a dinosaur and so is my equipment) and having taught
diving for 10 years during that time, I have watched as the diving
community has slowly drifted away from preaching buddy breathing towards
having a redundant air supply, wether that be a pony bottle, octopus, or
spare air. In my experience, all of these are good choices, depending on
the circumstances and the divers involved. There is no one solution that
buddy is around, so that too does not work all the time.
So, with that said, how many of you out there that dive with a
redundant air source use it on every dive? For an octopus system, do you
use it every dive? For a pony bottle setup, do you switch to it halfway
thru the dive or use it on the ascent? Spare Air is not very good, in my
opinion, and I don't know if it can be refilled, so I will leave that out.
A out of air emergency is not the time to be trying your alternate air
source. Checking it everytime before going in the water is also not good
enough, in my humble opinion. You need to be comfortable using what ever
form you dive with and the only way to do that is to dive with it all the
time, every time. Then, when the air stops, it is no big deal to switch
over. Plus, since it is no big deal, you are in a much better frame of
mind to deal with the situation at hand - paniky buddy, getting the h-ll
out of that wreck, or simply finding the surface.
I used to do a lot of deep diving, plus 120'. I dove almost
exclusively with a 80 plus 30 pony bottle. I would dive with the main tank
until I started to ascend or got to 1600psi, then switch over to the pony
for the ascent and any deco hangs. This has always left me with two tanks
half full at the end of the dive. I always thought this was smart, since
the air in the pony would hardly ever get used, if I dove the 80 the whole
dive. Don't get into how the 80 isn't enough air - for me, it is plenty of
air to a depth of 150'. For whatever reason, I have a very slow air
consumption rate and dive accordingly. But, that is not the point I am
trying to make here.
If you have a pony bottle, then you should use that pony bottle on
every dive, same goes for an octopus. If you don't like the way your
octopus breathes, then just think of how your buddy will like it when they
are desperate for air. Get an octopus that you can breathe on during a
dive. An to really go out on a limb, I also think the octopus should be
the easiest breathing regulator of the two you dive with.
Ok. I have said my piece and I hope it does not offend anyone but rather
makes you think about how you dive. I am not saying my way of thinking is
correct but I do think it warrents looking at and deciding for yourself if
I am on the right track.
Disagreements are the only way advances are made. If you think I am in
left field, then that is your right. I do not think anything I have said
is dangerous or will hurt anyone (I know it has never hurt any of my
students!!). I am open to different suggestions or even improvements on
what I do. Just don't sling mud.
Tom P.
Jenaer Mixmaster Anonserver
Quoth Perry West:
> Mixmaster (mixm...@remail.obscura.com) wrote:
>
> : In any case, some agencies advise that you keep your regulator in your mouth
> : during an emergency ascent so that you might benefit from the expanding air
> : in the hose. Dispensing with the above piffle (+), how can a Spare Air not
> : be an improvement over expanding air in the hose?
>
> The reason for keeping something (regulator, spare air, etc.) in your
> mouth while doing an emergency swimming ascent is not primarily because
> you will get a breath or two during the ascent (which as you point out,
> you will), but because a diver doing an emergency swimming ascent might
> have an uncontrollable urge to breathe. Having the regulator in the
> mouth will give at most nothing. With nothing in the mouth, the diver
> will most probably asperate water during this reflex and drown.
>
So, how is having something in the mouth that will deliver (more) air (than
a hose) worse?
> Regarding the spare air; I agree they are insufficient when used on
> deeper dives.
But, they can't be worse than nothing at all. (Unless you buy the specious
argument conveniently deleted from Perry's reply.)
> Was buddied up with a person on one trip who had a spare
> air as the redundant source (no octo). It was a very nervous time for
> me. I resolved if I ran out of air 1) to physically attach myself to
> this person, 2) to use the spare air until it was depleted and then throw
> it away, and 3) to give this person impromptu instruction in buddy
> breathing (i.e., if they want their regulator back, they needed to be a
> quick learner). I am happy to say I never had to put my plan into action.
>
> Regards,
> Perry
>
>
Were you forced to make the dive? Don't dive with someone who is improperly
equipped.
MLANE49
I would like to hear from someone who has had to use a
Spare Air (SA) in an emergency situation. I have a 2.7 SA and
a 13 Cu ft Pony. I use the SA for dives at say 60 feet. And the pony for
100 feet. Several responses have complained about
only one or two breaths at depth. I can very easily imagine the value of
one extra good breath in an emergency situation.
Am I just kidding myself?
Michael Liu
Lee Bell <"leebell@"@ix.netcom.com> wrote in article
<5t8bu8$d...@dfw-ixnews12.ix.netcom.com>...
>
> 1. There is no absolute criteria. If you are diving with a buddy,
> how much redundant air do you need? No matter what you answer,
> it's not enough for any and all situations which can occur. You
> set your risk limits and live or die by them. I'll do the same.
>
> 2. Some air is always better than no air, ALWAYS.
>
> 3. Having a spare air as a redundant air supply does not "promote" bad
> diving practices of any type. Neither does having a pony, doubles,
> or other emergency equipment. Only bad divers promote bad diving.
>
> 4. Neither you nor I are qualified to define bad diving practices in
> this context (buddy practices). Some people, inclding me, find
> the risk acceptable under certain cirumstances.
>
> Lee
I'm with Lee on this. The biggest problem with the Spare Air is people's
misconception of its use. A Spare Air will NOT allow you to dive in wrecks
or caves (but then again, neither would a pony). A Spare Air will NOT
allow you to extend your bottom time. A Spare Air will NOT allow you to
dive deeper than your abilities or your primary rig. A Spare Air will NOT
allow you to leisurely complete your dive after experiencing a catastrophic
air loss. A Spare Air will NOT allow you to make deco stops.
But for well trained divers operating within the bounds of "recreational
diving" (you may set your own limits here based on your training, skill,
and comfort level), the Spare Air can provide a measurable amount of
insurance. I purchased a Spare Air based on the following rational:
1. I manage my air very well. Lack of air management (which starts in the
pre-dive planning stage) is by far the primary cause of out-of-air
situations.
2. Equipment failure resulting in a TOTAL out-of-air situation is
extremely rare, especially will well-maintained gear. Yes it is possible,
but so is getting struck by lighting.
3. I never consider the Spare Air to be a substitute for any required
piece of gear, whether that be an octo or a pony or a full redundant rig.
4. I cannot always choose my buddy. Ideally, I would make every dive with
a buddy I knew and trusted, a buddy with whom I've had a lot of experience
and who has a similar diving style and goal. But this situation is often
not the case. Many times, I've had to dive with buddies who I've just met
the morning of the dive. And from some of the diving practices and
attitudes I've read about on this NG, I know there are many divers out
there that I would not trust in the shallow end of a pool. So it is
possible that one may find himself/herself diving with a buddy who won't be
there (physically and/or intellectually) when needed.
5. I like to travel and dive. I also like to do U/W photography. I have
one Pelican 1650 case (read: BIG) stuffed with U/W photo gear, one Pelican
1650 stuffed with dive gear, and one large carry-on filled with camera
gear. And that doesn't even account for the luggage for clothes/amenities.
I have no room to carry a pony. (Note: This does NOT mean that I dive in
situations where I feel I need a pony, but don't use one because I can't
fit it in the luggage.)
6. I have good JUDGEMENT to plan and execute my dives within the limits of
my training, skill, and experience. I would never take just a Spare Air on
a dive which I wouldn't feel comfortable making without ANY redundant air
supply.
So what is the purpose of a Spare Air? It is an option. It adds an
additional margin of safety (small, but reasonable). If I should ever have
a out-of-air situation in the conditions described above, I will do the
following:
1. Visually locate my buddy and determine if I can reasonably make it to
him/her, considering the environmental conditions, and buddy factors (e.g.,
does my buddy have sight of me?). If I feel I can make it, I will go to my
buddy and breath off his/her alternate and abort the dive. I will not use
the Spare Air to locate or reach my buddy because I'd save that for the
next option.
2. If I cannot locate my buddy or if I feel my buddy is too far or if I
try to reach my buddy and realize I'm not going to make it, I will then
execute an immediate ascent to the surface. This can be anything from a
"normal" ascent to an emergency buoyant ascent. (Side note: The July '97
issue of Rodale's Scuba Diving, lists the first three options for an
out-of-air situation to be the normal ascent, the emergency swimming
ascent, and the emergency buoyant ascent.) I will keep my reg in my mouth
and allow the expanding air in my lungs to exhale normally. If I feel I
need more air during the ascent, I will try to get it from my primary or my
octo. If that doesn't work, THEN I will go to the Spare Air to give me the
few breaths I need to surface. If I can make a safety stop, then that's
great. But I'd rather risk the bends than drown.
To paraphrase Lee, you can never eliminate the risk from any diving
scenario, all you can do is set your own limits.
--
Dive Safe!
Michael Liu
PADI OWSI-89560
PSI Visual Cylinder Inspector # 7131
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Bo Lawler
Perry West <pe...@netcom.com> wrote:
>Regarding the spare air; I agree they are insufficient when used on
>me. I resolved if I ran out of air 1) to physically attach myself to
>this person, 2) to use the spare air until it was depleted and then throw
>it away, and 3) to give this person impromptu instruction in buddy
>breathing (i.e., if they want their regulator back, they needed to be a
>quick learner). I am happy to say I never had to put my plan into action.
Unfortunately, this plan sounds like a sure recipe for a two-person
disaster. I can't think of a worse thing to do to a buddy than to
try, unannounced, to rip their air supply out of their mouth and put
it in your own. Perhaps a little review on the surface of
buddy-breathing technique would be a better plan.
Bo Lawler
Michael Liu
A Spare Air should never be a substitute for an octo.
Bob Beaumont/Patti O'Brien <o...@together.net> wrote in article
<33F8D3...@together.net>...
> When trying to evaluate alternative air sources, think about the out of
> air emergencies you've seen. The only one I've been close to (not a bar
> story) is when someone came up to my father and removed my father's reg
> while making a very polite slash across the throat. Fortunately, my
> dad's a pretty mellow guy. He pulled his bright orange octopus from the
> quick release tab on the bc (which was right in front of the out of air
> man, I might add) and they stayed put for a while until the guy
> recovered his brains, then they switched to the appropriate regs and
> made a safe ascent. Where was the other person's buddy? Who knows? He
> found out at the end of the dive when he couldn't find his buddy to
> surface.
>
> I would never dive without a second reg that gave me access to my tank.
> I can't see myself ripping my reg away from someone in trouble, but it
> takes more than a few breaths to sort out an underwater out of air
> situation. I surely wouldn't want to be sucking on a spare air. Also-
> people desperate for air flail about and generally do everything they
> shouldn't which include for get their name, spare air existence, etc.
>
> As nice as it would be to only have to plan for your safety, diving is
> often done in groups. And invariably the least prepared, most in
> trouble diver will turn to you underwater...
>
> Patti O'B
> o...@together.net
> Come and see the Bay Islands Beach Resort at <<http://www.bibr.com>>
>
Bob Beaumont/Patti O'Brien
Eanx Miss
I wish I had stock in "Spare Air"`since so many untrained divers think it
will bail them out. The only logical use for Spare Air is to teach in a
pool without putting on full gear. Obviously all these people buying this
product think they Are "Advanced Divers" and can go deep without proper
training, air managemnent rules, gear recon=fig. and proper certification.
The marketing of Spare Air has appealed to so many psuedo wannabe's
in the tech field, that I feel it is really a bad safety net that a lot of
divers could fall into feelin "I'm okay ,I've always got Spare Air" which
will give you about one breath in a full panic at 130'. Good luck to ya"..
Jenaer Mixmaster Anonserver
Quoth Perry West:
> Mixmaster (mixm...@remail.obscura.com) wrote:
>
> : In any case, some agencies advise that you keep your regulator in your mouth
> : during an emergency ascent so that you might benefit from the expanding air
> : in the hose. Dispensing with the above piffle (+), how can a Spare Air not
> : be an improvement over expanding air in the hose?
>
> The reason for keeping something (regulator, spare air, etc.) in your
> mouth while doing an emergency swimming ascent is not primarily because
> you will get a breath or two during the ascent (which as you point out,
> you will), but because a diver doing an emergency swimming ascent might
> have an uncontrollable urge to breathe. Having the regulator in the
> mouth will give at most nothing. With nothing in the mouth, the diver
> will most probably asperate water during this reflex and drown.
>
So, how is having something in the mouth that will deliver (more) air (than
a hose) worse?
> Regarding the spare air; I agree they are insufficient when used on
> deeper dives.
But, they can't be worse than nothing at all. (Unless you buy the specious
argument conveniently deleted from Perry's reply.)
> Was buddied up with a person on one trip who had a spare
> air as the redundant source (no octo). It was a very nervous time for
> me. I resolved if I ran out of air 1) to physically attach myself to
> this person, 2) to use the spare air until it was depleted and then throw
> it away, and 3) to give this person impromptu instruction in buddy
> breathing (i.e., if they want their regulator back, they needed to be a
> quick learner). I am happy to say I never had to put my plan into action.
>
J Shepherd
This argument is as specious as saying that drivers of cars equipped
with
airbags will take more chances than those who drive cars not so
equipped.
It's right up there with "Motorcycle riders who wear helmets take more
risks
than those who do not." +
Bullshit, poppycock, nonsense, balderdash, blather, bunkum, claptrap!
And unfortunately, statistically proven.
Reality walks up with a cold wet kipper again.
Jason
Jason
I think most of you are making a big mistake when disscussing the
differences between a Spare Air and a pony bottle. I have seen lots of
posts which talk about making a normal asscent with a Spare Air. That
is not what they were designed for. They are an emergency supply,
enough air to get you to the surface. Yes, you might get bent from such
a speedy asscent, but it is better than being dead.
Jason
Secret Squirrel
Quoth J Shepherd:
> This argument is as specious as saying that drivers of cars equipped
> with airbags will take more chances than those who drive cars not so
> equipped. It's right up there with "Motorcycle riders who wear helmets
> take more risks than those who do not." +
>
> Bullshit, poppycock, nonsense, balderdash, blather, bunkum, claptrap!
>
>
> And unfortunately, statistically proven.
It is not possible to prove anything with statistics. Support perhaps, but
not prove.
Anyway, I'd rather see the data analyzed by a competent statistician with no
position in the argument than take the word of someone trying to support a
position. (Which doesn't mean you by the way. I may refer to your source.)
>
> Reality walks up with a cold wet kipper again.
>
> Jason
>
Simply for purposes of argument, not because I believe it, let's suppose
that there are drivers that take more risks because cars are equipped with
air-bags or because they wear helmets on motorcycles.
With that supposition, let's examine reality.
Have fatality rates for those specific groups gone up during the widespread
use of air-bags and helmets?
Have fatality rates in the general population gone up during the widespread
use of air-bags and helmets?
If the answers are Yes/Yes then let's hang the air-bag and helmet
advocates and manufacturers.
If the answers are No/No then who cares if some sub-group takes more risks?
If the answers are Yes/No then natural selection will improve the species.
If the answers are No/Yes then the general population needs driving lessons.
The case against Spare Air always degenerates to a case against stupid
divers. I recall similar resistance to computers and advances in tables.
Tim J. Patterson
Chiming in from the side lines......
> Anyway, I'd rather see the data analyzed by a competent statistician with no
> position in the argument than take the word of someone trying to support a
> position. (Which doesn't mean you by the way. I may refer to your source.)
There are a lot of specious arguements on this thread (and yes I am a
competent statistician although I can't spell) For some reason, people
don't seem to be able to understand that there is a difference between
correlation and causality. Further, with control of the sample set
and so forth, nearly any conclusion can be drawn (often accomplished
without even attempting to do so due to the observers inherent biases.)
> Have fatality rates in the general population gone up during the widespread
> use of air-bags and helmets?
>
There is a huge debate in the motorcycle group about helmets - there
are statistics showing increase in fatalities/accident with
helmets. Fun debat.
> The case against Spare Air always degenerates to a case against stupid
> divers. I recall similar resistance to computers and advances in tables.
A much better arguement against Spare Air is that for nearly the same
cost, a pony bottle gives a more effective back up for a much wider
variety of dive profiles.
There are advantages and disadvantages to both backups. A proper
decision must be made on the basis of the sort of diving one does
knowing the advantages and disadvantages.
I own both backup systems and choose what I will carry based on the
dive circumstances. If I was to choose to keep only one - the pony
gets the definate preference.
--
Tim J. Patterson Ph.D.
Senior Associate
Booz Allen & Hamilton
Sunnyvale CA
A7WIENS
<<< you can never eliminate the risk from any diving
scenario, all you can do is set your own limits.>>>
Darwin as he reaches out to spank you!!!!
Fishbre396
In article <19970818161...@ladder02.news.aol.com>,
bake...@aol.com (Baker Tom) writes:
>Having just started looking at this newsgroup, I thought this
>particular topic would be a little heated. Having been diving for over 20
>years (yes, I am a dinosaur and so is my equipment) and having taught
>diving for 10 years during that time, I have watched as the diving
>community has slowly drifted away from preaching buddy breathing towards
>having a redundant air supply, wether that be a pony bottle, octopus, or
>spare air. In my experience, all of these are good choices, depending on
>the circumstances and the divers involved. There is no one solution that
>will work with everyone or everytime. An octopus will only work if your
>buddy is around, so that too does not work all the time.
>
>
Tom, I agree with your entire note! Thank you for posting your opinion.
Fishbre396
Don Beissel
I was doing dives for my advanced O/W this past weekend and brought this
arguement up to him because it shows up on almost every scuba discussion
group.
He said:"What a stupid arguement. Why are you running out of air in the
first place."
I tend to agree. Free flow, etc.... happen. But your buddy (whom you
should always be close enough to reach) should have an octpus and air to
make a safe ascent.
My $.02
Now I put on the asbestos wetsuit to take all the flames I am sure to get
over this......
Don Beissel
J Shepherd
Lee Bell <"leebell@"@ix.netcom.com> writes:
>J Shepherd wrote:
>
>> I disagree. There is an absolute criteria - is it enough. If the
>> answer is no, then it is not 'better than nothing'. Indeed, by
>> suggesting to the the diver that he now has a 'redundant air supply'
>> it promotes bad buddy diving practice.
>Sorry Jason, but you're wrong.
Well, I'm still diagreeing;
>1. There is no absolute criteria. If you are diving with a buddy,
> how much redundant air do you need? No matter what you answer,
> it's not enough for any and all situations which can occur. You
> set your risk limits and live or die by them. I'll do the same.
For what purpose are you taking your RAS? To get to your buddy
under normal buddy diving situations - not, to raise the Titanic if the
opportunity arises, not, to travel 100m to him because he's being a
prick, not, to ascend to the surface from 40m for similar reasons.
I however, carry my RAS to do exactly that; and I can calculate
if it is enough. Note, not 'enough to breath whilst trapped under fallen
wreckage deep inside the Mark Graf' but enough to take a kit failure on
the outside of the wreck and ascend, or to exit the wreck and find my
buddy.
I would maintain that a SA has enough air to get you to your
buddy or the surface only under such a restrictive set of cirumstances
as to be practically useless.
>2. Some air is always better than no air, ALWAYS.
Agreed. But 1 breath to few is the same as 100 breaths too few.
You die. You need *enough*, not some, to survive.
>3. Having a spare air as a redundant air supply does not "promote" bad
> diving practices of any type. Neither does having a pony, doubles,
> or other emergency equipment. Only bad divers promote bad diving.
>
Unfortunately there are an awful lot of bad divers out there
proving you wrong. 'If my buddy runs out of air, they surface, I carry
on; I'm OK solo because I have a SA'. 'I'm redundant and can do deco
diving because I have a pony' - no mention of gas management, just 'I'll
be OK'. 13cuft suddenly means that you're redundant.
IME, and by my own observation, you are incorrect.
>4. Neither you nor I are qualified to define bad diving practices in
> this context (buddy practices). Some people, inclding me, find
> the risk acceptable under certain cirumstances.
On the contrary. We are the *only* people qualified to define
them. We do it - no one else does what we do. Are we qualified to define
what others should do? Yes, and they are qualified to argue back. And in
so doing we all learn.
I (would) find the risk acceptable under some circumstances.
Indeed, I've explained one set you the group already. But I survived
what by many people's criteria was an *ideal* solo dive, merely because
of my buddy - I knew the site inside out, I was dived up and
experienced, I was fit, it was shallow (25m max) no stop, no tides,
shore diving, heck we used it as a training spot. Same site killed a
friend of mine last year.
I take buddy diving very, very seriously. As seriously as I take
solo diving. I don't want to sound melodramatic but working out your SAC
to the end of your life, and the weight of a coffin, are two things that
make you look at risk assessment very differently.
Jason
>Lee
lcs Mixmaster Remailer
Quoth J Shepherd:
> This argument is as specious as saying that drivers of cars equipped
> with airbags will take more chances than those who drive cars not so
> equipped. It's right up there with "Motorcycle riders who wear helmets
> take more risks than those who do not." +
>
> Bullshit, poppycock, nonsense, balderdash, blather, bunkum, claptrap!
>
>
> And unfortunately, statistically proven.
It is not possible to prove anything with statistics. Support perhaps, but
not prove.
Anyway, I'd rather see the data analyzed by a competent statistician with no
position in the argument than take the word of someone trying to support a
position. (Which doesn't mean you by the way. I may refer to your source.)
>
> Reality walks up with a cold wet kipper again.
>
> Jason
>
Simply for purposes of argument, not because I believe it, let's suppose
that there are drivers that take more risks because cars are equipped with
air-bags or because they wear helmets on motorcycles.
With that supposition, let's examine reality.
Have fatality rates for those specific groups gone up during the widespread
use of air-bags and helmets?
Have fatality rates in the general population gone up during the widespread
use of air-bags and helmets?
If the answers are Yes/Yes then let's hang the air-bag and helmet
advocates and manufacturers.
If the answers are No/No then who cares if some sub-group takes more risks?
If the answers are Yes/No then natural selection will improve the species.
If the answers are No/Yes then the general population needs driving lessons.
The case against Spare Air always degenerates to a case against stupid
H Huntzinger
Mixmaster wrote:
>
> >hammond@not@peek.enet.dec.com (Charlie Hammond) wrote:
> >
> >>Consider the diver who does not have your enviable ability to ascend from
> >>this diver would be more likely to plan a dive within his/her limits.
> >
> >>So, is this diver better off with a spare air than without?
> airbags will take more chances than those who drive cars not so equipped.
Um...tell that to my Auto Insurance company??
Unfortunately, there has been some recent research that substantiates
this
"will tend to get into more trouble" supposition.
-hh
H Huntzinger
Michael Liu wrote:
>
> ...The biggest problem with the Spare Air is people's
> misconception of its use...
Agreed.
> But...I purchased a Spare Air based on the following rational:
>
>
> 3. I never consider the Spare Air to be a substitute for any required
> piece of gear, whether that be an octo or a pony or a full redundant rig.
> ...
> 5. I like to travel and dive. I also like to do U/W photography. I have
> one Pelican 1650 case (read: BIG) stuffed with U/W photo gear, one Pelican
> 1650 stuffed with dive gear, and one large carry-on filled with camera
> gear. And that doesn't even account for the luggage for clothes/amenities.
> I have no room to carry a pony. (Note: This does NOT mean that I dive in
> situations where I feel I need a pony, but don't use one because I can't
> fit it in the luggage.)
Hmmm...it sounds like to me that #5 conflicts with #3: ie, you consider
the SA a substitute for the pony bottle that you "don't have room for".
In any event, I merely wanted to point out that I'm also a travelling
UW photographer and I easily found room to pack a 13ft pony.
The "pony is too big" arguement is lame - a 13ft pony is *HALF* the
size/mass of most UW cameras...your REAL priorities are evident.
> ... If I should ever have
> a out-of-air situation in the conditions described above, I will do the
> following:
>
> 1. Visually locate my buddy and determine if I can reasonably make it to
> him/her...
> 2. If I cannot locate my buddy or if I feel my buddy is too far or if I
> try to reach my buddy and realize I'm not going to make it, I will then
> execute an immediate ascent to the surface...
Your first priority should have been to reestablish your air supply.
In this case, that means to swap out to your SpareAir and then decide
if your buddy is close enough, etc. If you don't do this first, you
may not have the time to try the other actions.
-hh
J Shepherd
Jason <jas...@ix.netcom.com> writes:
>Jason
Once you're in the position of having accepted that, look at the
other options available to you:
Ditch weights - cost, 30UKP tops.
ABLJ bottle - cost, 70UKP, 15UKP/year.
Swimming ascent, head back - zero.
SA - ???
Again, better bent than dead.
Jason
J Shepherd
Squirrel, since you didn't get your address back to me, I'm
cutting and pasting the reply onto the news group. If you want to go
private, bin the spam block.
>
> Anyway, I'd rather see the data analyzed by a competent statistician
with no
> position in the argument than take the word of someone trying to
support a
> position. (Which doesn't mean you by the way. I may refer to your
source.)
>
Chief statistician of the Scottish Office (recently retired).
>
> The case against Spare Air always degenerates to a case against stupid
> divers. I recall similar resistance to computers and advances in
tables.
>
Absolutely. 99% of divers, it appears, are stupid about one
thing
or another. Most divers still have trouble getting through a weeks RDP
planning. MOst computer users don't read or follwo the manual; don't
understand the loading dynamics of chasing a no-stop time up a reef;
ignore TTF warnings if they're inconvenient, and appear to assume that
the
only type of failure an aircrafts compression system can have is to blow
the aeroplane up, rather than just dropping cabin pressure 10-25%.
The SA is *sold* as a redundant air source.
It was *built* to get people out of ditched helicopters and it
barely worked for that...
This is of course, JMO, but there's no reason to debate it. As
for
the above debate, we *have* had one poster recently who was prepared to
continue his dive solo if his buddies air ran out 'because I've got my
spare air' (paraphrased).
This is 'the presence of a sub-optimal safety system inducing
false confidence and promoting unsafe diving practices'. So we *know* it
happens. IME <--Experience, note, it happens a lot.
Cheers,
Jason
Carl Elleard
Actually, there is no case, per se, AGAINST Spare Air. More often,
there is a comparison between Spare Air or a pony tank and, that given,
what size pony. The question becomes one of "What is safe enough?"
That is a personal question.
I dive solo and with lots of very inexperienced divers. Given that, I
opt for a pony bottle (30cf). I read that the difference is a few
breaths. Well, anyone who has ever dealt with an emergency underwater
knows, absolutely, that it is not a matter of a "few breaths". A few
breaths are gone just trying to stabilize the situation from panic to
solution. The the Spare Air is gone and the pony might seem a more apt
choice.
But again, it is a personal choice. Whatever you feel safe with should
be your choice. But, it is fairly easy to calculate the number of
breaths you can get from a certain capacity of container and get
somewhat close. Then go to, say, 60 feet and simulate an emergency
(using all applicable safeguards, of course). Try to remedy the problem
and surface using only the number of breaths your container holds. I
find that a 30 is the right size for working with other divers, although
a 19 could easily suffice (I err on the side of caution). Diving solo,
a 19 or even 13 would work.
lcs Mixmaster Remailer wrote:
>
> Quoth J Shepherd:
>
> > This argument is as specious as saying that drivers of cars equipped
> > with airbags will take more chances than those who drive cars not so
> > equipped. It's right up there with "Motorcycle riders who wear helmets
> > take more risks than those who do not." +
> >
> > Bullshit, poppycock, nonsense, balderdash, blather, bunkum, claptrap!
> >
> >
> > And unfortunately, statistically proven.
>
> It is not possible to prove anything with statistics. Support perhaps, but
> not prove.
>
> Anyway, I'd rather see the data analyzed by a competent statistician with no
> position in the argument than take the word of someone trying to support a
> position. (Which doesn't mean you by the way. I may refer to your source.)
>
> >
> > Reality walks up with a cold wet kipper again.
> >
> > Jason
> >
>
> Simply for purposes of argument, not because I believe it, let's suppose
> that there are drivers that take more risks because cars are equipped with
> air-bags or because they wear helmets on motorcycles.
>
> With that supposition, let's examine reality.
>
> Have fatality rates for those specific groups gone up during the widespread
> use of air-bags and helmets?
>
> Have fatality rates in the general population gone up during the widespread
> use of air-bags and helmets?
>
> If the answers are Yes/Yes then let's hang the air-bag and helmet
> advocates and manufacturers.
>
> If the answers are No/No then who cares if some sub-group takes more risks?
>
> If the answers are Yes/No then natural selection will improve the species.
>
> If the answers are No/Yes then the general population needs driving lessons.
>
Haux
I've always heard the leaks, and sometimes was able to see them, when my
hi or low pressure hoses decided it was time to give out.
Your second point about people not checking their SPG frequently reminds
me of a recent experience I had while diving in a loose group of 5 divers.
Two of the divers were new to diving and used a lot of air. They checked
their SPG's frequently but didn't respond to a low air situation.
About 25 minutes into the dive they showed me their SPG's and had about
900 psi left. I motioned for them to ascend and do a safety stop. They
just stayed with the group. A couple minutes later they again showed me
their SPG's and were down to 700 psi. I again motioned for them to go up
and do a safety stop, but they stayed with us.
At this point, it hit me that they were probably going to stay down with
the rest of us at 65 feet until they ran out of air, so I led them up, did
the safety stop with them, and ended up with a short dive.
Point is, if you're using air faster than your buddy, do your dive 10 feet
above him/her. If you're getting real low on air, go up and do a swimming
safety stop, then continue to swim along towards the boat. If worst comes
to worst, surface after your safety stop and do a surface swim back to the
boat. Before I get flamed, your buddy should go up with you too.
Ron
>Is is possible to develop an air leak in a hose or fitting?
>Is it possible that one might not hear or see such a leak?
>
>For those folks who don't check their SPG frequently, is it possible
>to run out of air while still on plan?
Fishbre396
In article <19970827141...@ladder01.news.aol.com>, ha...@aol.com
(Haux) writes:
>I've always heard the leaks, and sometimes was able to see them, when my
>hi or low pressure hoses decided it was time to give out.
You're right . . . that distinguishable HISSSSSSSS, and at times there is
a loud POP before the HISSSSSSSSSSSSS. But, one must have to have good
ears to hear this . . . some just don't have very good hearing.
Jason Rogers
r...@netcom.com (Richard Hyde) writes:
>I'm new to the sport, so perhaps this is a dumb question... :-)
It's and excellent question.
>Is is possible to develop an air leak in a hose or fitting?
Yes
>Is it possible that one might not hear or see such a leak?
It's possible, but unlikely (I have heard of it, and it was
mentioned in "the darkness beckons")
>For those folks who don't check their SPG frequently, is it possible
>to run out of air while still on plan?
Even with checking the SPG, you can still run out of air. They
sometimes stick (this is their normal failure mode) and read
high while the pressure is falling. Richard Pyle (a genuine
dive god) had to do an emergency ascent from some mega depth,
missing *all* his deco as a result of a sticking gauge.
>I don't know much about diving yet, but as a pilot the fuel gauge
>is a regular part of my scan. I always know without looking roughly
>how much fuel I have, but I frequently check the gauges anyway to
>make sure that something unexpected isn't silently draining it
>away...
I recently read an accident investigation on a crashed twin engined
aircraft. The pilot reported one engine rough. Then one engine
cut out, and the second rough. That was the last they heard of
him. Crash investigation showed that the filler cap had been
leaking. Being on the top of the wing, in the low pressure zone,
it had sucked out the fuel. The fuel was contained in soft bags,
and the bottom of the bag was pulled up by the low pressure, and
held the fuel level float in the up position, so the gauges
read full.
Gauges lie.
>Rick
Cheers Jason =:)
>--
>Include "wombat" in Subject: line of mail sent to me [to override spamgard(tm)]
>------------------------------------------------------------------------------
>| Richard Hyde | R...@netcom.com | This space intentionally left blank |
>------------------------------------------------------------------------------
Tim J. Patterson
>
> FWIW, according to a DAN accident analysis report published within
> the last year or so, the #1 reason for divers to run out of air
> was FAILURE TO MONITOR THEIR AIR SUPPLY.
>
> This is an extremely basic human error and entirely preventable IMO.
My approach - I have an el-cheapo casio watch with a count down beaper
which I set to go off at a regular interval which reminds me to check
my gauges. I use a shorter interval on deep dives (like 6-7 minutes)
and a longer for more shallow dives. This avoids the relative sense
of time passing depending on what is happening and gets me to glance
often enough that I can project consuption rates at depth and would
even likely catch a stuck gauge as the data would be inconsistent with
the series of readings.
My only question is one that after several years of use, the casio
battery is likely to die soon and I've not found a good replacement.
Tim
H Huntzinger
Richard Hyde wrote:
>
> Charlie Scogin (cwsc...@anet-dfw.com) wrote:
> : <snip>
>
> : > > I resolved if I ran out of air 1) to physically attach myself to
>
> : Wouldnt you plan not to run out of air? I return to the basic falicy of this whole
> : discussion. If you plan your dive and dive your plan then, at least in my plans, I
> : dont run out of air. Sans the need for a pony and/or a spare air.
>
> I'm new to the sport, so perhaps this is a dumb question... :-)
>
Yes, absolutely. There are many potential sources of mechanical
failures that can leave you without air _despite your plan_.
Here's a few failure modes:
- HP hose burst - Obvious, slow loss of air supply
- LP hose burst - Obvious, FAST loss of air supply
- Freeze-up - Obvious; effects & rates vary (Ice diving, etc is here)
- Bad SPG - Generally NOT obvious: pressure gage may read
a fixed or variable offset "X high" or "Y low" or
it may simply get STUCK at a pressure and not move
whatsoever while you breathe the tank out.
- Air-Integrated Dive Computer Failure:
- Can be obvious (blank screen) or inobvious (bad readout)
and generally has to be considered to be completely
unpredictable for its likely failure modes and therefore
potentially insidious in nature.
- Tank "O" ring failure - Obvious, fast? (comments, anyone?)
- Mouthpiece - tie-wrap fails and it comes off the regulator,
or you bite through the tabs. In both cases,
you'll probably suddenly swallow water. Granted,
this isn't a "real" OOA, but its related.
- Tank Burst Disk - Obvious, fast.
- Regulator Filter Clog - Varies, varies. This failure mode was
reported here on the Net a few years ago.
Som crud in the bottom of a tank got into
the 1st stage's air intake and cloged it up,
thus cutting off the diver's air supply.
While reviewing this list, note that for how many of them how
switching over to your Octopus doesn't do you any good.
> For those folks who don't check their SPG frequently, is it possible
> to run out of air while still on plan?
Yup. In fact, not paying close enough attention is the #1 reason
why divers run out of air...a very basic and preventable human error.
-hh
Jason Rogers
Charlie Scogin <cwsc...@anet-dfw.com> writes:
>Jason Rogers wrote:
><snip>
>> Gauges lie.
>Jason,
>Most definetly guages lie and should not be trusted, but still, I know
>that if I have been diving to 120 feet for 30 minutes and my guage reads
>2800psi, something is wrong! As I scan my guage as time progresses, it
>should be going down, I am not going to be surprised at 250psi. If I am
>I sure am not paying attention, and when diving, if one thing I pay
>attention to its my air supply.
Sure, if after half an hour it reads 2800, you're going to know
that something is wrong, if it reads nearly full. What if after
half an hour it reads 750 psi? Will you think "Hmmm, my air consumption
is getting a little better!" or will you think, "Hmmm, my
gauge might be reading 500 psi high, and I might not have
enough gas for my deco"
Cheers Jason =:)
KybrSose
JF mezei writes
" lets assume this is for recreational dives only."
WHY???
Is the ocean more forgiving to recreational divers???
Self sufficency should be every divers goal.
What if you cant get free from the bottom???
What if you and your buddy are entangled???
If you have time you can cut away. Redundancy gives you this time.
You can drown in a bathtub if you cant get up.
Pony bottles give you time to solve related problems.
JF writes further
"Both should lose their cert. cards.....<snip>"
You can worry about cards at the surface , when you get there, if you
are still alive.
safe diving Al Marvelli
jf mezei
Jason Rogers wrote:
> Sure, if after half an hour it reads 2800, you're going to know
> that something is wrong, if it reads nearly full. What if after
> half an hour it reads 750 psi? Will you think "Hmmm, my air consumption
> is getting a little better!" or will you think, "Hmmm, my
> gauge might be reading 500 psi high, and I might not have
> enough gas for my deco"
That is why you need to also check your buddy's gauge regularly. Not
only
to make sure that he doesn't run out of air, but also to compare your
own consumption with his. And it doesn't take that much diving
experience
before you get a feel for what a buddy's consumption is compared to
yours,
and you should be able to spot that something is wrong well before you
run out of air.
jf mezei
KybrSose wrote:
>
> JF mezei writes
> " lets assume this is for recreational dives only."
>
> WHY???
>
> Is the ocean more forgiving to recreational divers???
Yes. Because recreational divers should not be getting themselves into
depths or environment that are truly dangerous. That it is called "open
water". Recreational divers should never dive solo and a buddy should
always be close at hand. With this in mind, it really doesn't take all
that much air left in your tank for someone to ascend. Yeah sure, you
can't dive for the remainder of the day if you shoot past the safety
stops
but you should survive.
> What if you cant get free from the bottom???
> What if you and your buddy are entangled???
> If you have time you can cut away. Redundancy gives you this time.
Pretty unlikely that both your and your buddy's air supply will fail
during
the same dive.
KybrSose
JF Mezei writes
"Recreational divers should not be getting themselves into depths or
environment that are truly dangerous"
You can drown in two feet of water. You can embolize in four feet of water.
what depth is "safe"????
What is a truly dangerous environment to you ,JF?
is there a place in the ocean where people do not fish??
Is there a place in the ocean where you will never encounter some
type of entanglement hazzard???
Im not talking wrek penetration here---- in "open water can you
really ever be sure you will not become entangled? ??
Ever??? Are you willing to bet your life on it???
Jf writes <snip>
"never dive solo and a buddy should always be close at hand"
What do you do if both you and your buddy have simultaneous problems???
What if you and your buddy have multiple problems simultaneously???
But you dont have these problems because you are a recreational diver on
a recreational dive, right ?
You only get to die once. Its your choice. Safe diving.
Al
Marvelli
jf mezei
KybrSose wrote:
> What is a truly dangerous environment to you ,JF?
>
> is there a place in the ocean where people do not fish??
> Is there a place in the ocean where you will never encounter some
> type of entanglement hazzard???
>
> Im not talking wrek penetration here---- in "open water can you
> really ever be sure you will not become entangled? ??
> Ever??? Are you willing to bet your life on it???
I have not become entangled. But I must wonder just how long it would
take
to untangle yourself. And when you are really low on air, the goal is
not to
find your way back to the boat or shore, it is to get to the surface.
And at 40m, with a safe ascent rate, it takes 133 seconds (2 minutes 13
seconds).
Considering that you can ascend the last 10m "free" on a single breath
(since
volume of air doubles, you can ascend while constantly exhaling and not
feel out of breath), you can argue that at 40m, you only need enough air
to get to
10m, and that would take only 1 minute 40 seconds.
Also, considering that you should always plan dives to allow at least a
5 minute safety stop, this means that you should always begin an ascent
with at least 7.5 minutes worth of air left.
Now, if you have 7.5 minutes of air left, and get entangled just as you
start
to ascend, you basically have a whole 5 minutes to untangle yourself and
still enough air to ascend to surface. Sure, by skipping the safety
stop, you probably forfeit subsequent dives that day and increase your
risk of DCS, but
you are not dead.
Fishbre396
In article <19970831171...@ladder02.news.aol.com>,
kybr...@aol.com (KybrSose) writes:
> " lets assume this is for recreational dives only."
>
> WHY???
>
> Is the ocean more forgiving to recreational divers???
NO, the ocean is not more forgiving, in fact it's usually much less forgiving.
>
> Self sufficency should be every divers goal.
I can agree with that.
>
> What if you cant get free from the bottom???
>
> What if you and your buddy are entangled???
>
> If you have time you can cut away. Redundancy gives you this time.
>
> You can drown in a bathtub if you cant get up.
I can agree with the above statement too!
Fishbre396
In article <3409F9...@videotron.ca>, jf mezei
<"[non-spam]jfmezei"@videotron.ca> writes:
>Yes. Because recreational divers should not be getting themselves into
>depths or environment that are truly dangerous. That it is called "open
>water".
Are you suggesting that recreational divers are not diving open water???
John Brett
This is a fine, laudable attitude that goes out of the window as soon
as you start looking at deco.
No deco, 3mins max to surface (assuming you blow the safety stops if
low on gas), no big deal if you're down by 250psi.
10+ minutes deco - you don't want any surprises with your gas supply.
Its not enough to not run *out* of air on the bottom.
(ps checking a buddy's gauge doesn't work if you're diving solo. Given
that Jason does serious deco diving solo, I hope you can understand
his justified paranoia regarding gas supply).
John Brett BS-AC * PADI * IANTD
jf mezei
Fishbre396 wrote:
> Are you suggesting that recreational divers are not diving open water???
No, I am suggesting that the definition of "open water" is an
environnement
where the dangers from diving are matched to the experience levels of
recreational divers, which, in reality, are fairly minimal.
The whole idea of this "spare air" is that someone should have equipment
which matches the environment to be dived.
If you are not equipped with a knife and with just a basic tank, you
should
not venture into a kelp forest where you may get entangled with your
tank already fairly low on air.
If you venture into a wreck with proper training, you'll probably have
spare TANKS and plenty of equipment to get you untangled.
My point: there are limits to recreational diving. All divers should be
well aware of their own limits, and in no way, should they think that a
little Spare Air cartridge should extend such limits.
jf mezei
John Brett wrote:
> This is a fine, laudable attitude that goes out of the window as soon
> as you start looking at deco.
>
> No deco, 3mins max to surface (assuming you blow the safety stops if
> low on gas), no big deal if you're down by 250psi.
>
> 10+ minutes deco - you don't want any surprises with your gas supply.
> Its not enough to not run *out* of air on the bottom.
I agree. However, do you consider deco diving to be "recreational"
diving ?
Also, if the times to surface during deco dives are so great, are
Spare Air bottles of any use ? In other words, in such dives, would
Spare Air be considered at all ?
KybrSose
JF Mezei writes
"Ihave not become entangled But i wonder....."
Entanglement can be resolved if you have enough gas to breathe.
The easiest means of resolving entanglement is to cut with a knife or
scissors.
How long will this take??? depends on the entanglement.
Will you breathe faster under the stress of being entangled and while
working to free yourself????
Yes.
does the volume of air in a scuba cylinder double or is the density
increased as you ascend??
I think it is the density. this means as you ascend you can breathe the
same volume of gas longer.
As far as all the numbers go remember the tables are theory not an
absolute predictor of bends.
As far as getting entangled on some time schedule,
It never happens to me like that!
Entanglement tends to be stressful even when your used to it.
How stressful is something youve never dealt with that could kill you??
Proper prior planning prevents piss poor performance.
Its your choice. Safe diving Al Marvelli
Fishbre396
In article <340B77...@videotron.ca>, jf mezei
<"[non-spam]jfmezei"@videotron.ca> writes:
>My point: there are limits to recreational diving. All divers should be
>well aware of their own limits, and in no way, should they think that a
>little Spare Air cartridge should extend such limits.
>
>
I agree with your final statement. Thank you for the rest of the
explaination.
J Shepherd
kybr...@aol.com (KybrSose) writes:
>Jason wrote
> ".....the pony is triple redundancy......."
> Um im like lost here. How is an octopus reg or second second stage
>redundant??
Diver self help is level 1 - *don't run out of air*.
Diver assistance is level 2 - your buddy is a valid source of
extra gas, assuming both of you are buddy diving properly. None of this
hooey about 'sometimes I can't reach him' - that's not buddy diving.
Redundant gas sources are level 3.
> A spare air equals zero redundancy. There is not enough gas for you or
>your buddy to resolve anything except who wins the fight for the remaining
>regulator aka who gets to free ascend.
Agreed.
> Proper prior planning prevents piss poor performance.
pppppprobably. It certainly helps. I think good diving practice
(which establishes the first two levels of redundancy) falls into this
category. and until you've got that right, I don't think anyone should
be mucking around with multiple tanks...
> Its your choice. Safe diving.
> Al Marvelli
Likewise.
Jason
Dan Masi
J Shepherd wrote:
> I would maintain that a SA has enough air to get you to your
> buddy or the surface only under such a restrictive set of cirumstances
> as to be practically useless.
Here's my situation, tell me if you think it's useless. I'm chartering
a sailboat in the caribbean. I'm anchored in a small, sheltered bay
that generally always has a few sea turtles hanging around. My buddy
feels like lounging on the deck with a book, I feel like saying
hi to the turtles. Vis is 60 to 100 feet, sunny... the bay's like
a flat lake. Bottom is sand at 25-35 feet. I'm not gonna dive
without SOME kind of redundant air source. If I limit my depth
to 30 feet, do you still agree that my SA is useless?
--
Dan Masi
Mentor Graphics Corp.
dan_...@mentorg.com
KybrSose
Dan,
yes
Al Marvelli
J Shepherd
Dan Masi <da...@warren.mentorg.com> writes:
>J Shepherd wrote:
Yes. Under such conditions you *don't* need a redundent air
source - drop your belt and go, look up and swim. Sure, you can spend
all that money if you really want, but c'mon...
Or KISS and snorkle all day for virtually no outlay.
Jason
H Huntzinger
jf mezei wrote:
>
> KybrSose wrote:
> > What is a truly dangerous environment to you ,JF?
> >
> > is there a place in the ocean where people do not fish??
> > Is there a place in the ocean where you will never encounter some
> > type of entanglement hazzard???
> >
> > Im not talking wrek penetration here---- in "open water can you
> > really ever be sure you will not become entangled? ??
> > Ever??? Are you willing to bet your life on it???
>
> I have not become entangled. But I must wonder just how long it would
> take to untangle yourself.
Go to your local fishing tackle store, buy a roll of SPIDER WIRE brand
fishing line (or equivalant) and start to chomp away with your dive
knife.
Its very nasty stuff.
For an even better test, tie off a piece of line to a ~10lb lead weight
and the other end onto a clip that you can clip yourself off to, then
go "entangle" yourself in the controlled environment of a swimming
pool.
Remember to monitor the amount of time it takes and your air consumption
so that you can corrolate to deeper diving depths. This is a much more
realistic test because you lose leverage while UW, which makes the line
harder to cut (assuming you can SEE it to cut it :-).
> Also, considering that you should always plan dives to allow at least a
> 5 minute safety stop, this means that you should always begin an ascent
> with at least 7.5 minutes worth of air left.
>
> Now, if you have 7.5 minutes of air left, and get entangled just as you
> start to ascend, you basically have a whole 5 minutes to untangle yourself...
No you don't. The 5 minutes of air for your ~10fsw (5m) safety stop
only provides ~90 seconds at 132fsw (40m). Please get your math right.
> ...Sure, by skipping the safety stop, you probably forfeit subsequent dives
> that day and increase your risk of DCS, but you are not dead.
If you don't exceed the max ascent rate of your deco model, its no
problem
to continue diving that same day - - which is another point of making
sure to carry enough redundant and/or reserve air for such
contingencies.
-hh
Tim J. Patterson
> > > I would maintain that a SA has enough air to get you to your
> > > buddy or the surface only under such a restrictive set of cirumstances
> > > as to be practically useless.
> >
> > Here's my situation, tell me if you think it's useless. I'm chartering
> > a sailboat in the caribbean. I'm anchored in a small, sheltered bay
> > that generally always has a few sea turtles hanging around. My buddy
> > feels like lounging on the deck with a book, I feel like saying
> > hi to the turtles. Vis is 60 to 100 feet, sunny... the bay's like
> > a flat lake. Bottom is sand at 25-35 feet. I'm not gonna dive
> > without SOME kind of redundant air source. If I limit my depth
> > to 30 feet, do you still agree that my SA is useless?
>
> At 30 feet you can take you last breath and head for thesurface, no
> safety stop unless your using Quad 120's.....SA is still almost
> useless....
You are changing the scenario -
You can probably expect to find your oh-#$%& about your air when you
try to inhale after largely emptying you lungs exhaling. Having
another breath available within seconds could be much nicer than going
for the surface while trying not to inhale which your body really
wants to do would be nice.
Everybody gripes about how little air is in the SA but at 30 feet
(quick back of the envelope ... an 80 lasts me 90 minutes at 30' so
2.7 feet should give about 3 minutes of use) the air will last
significantly longer then the often quoted one breath.
John Brett
On Mon, 01 Sep 1997 21:32:00 -0500, jf mezei
<"[non-spam]jfmezei"@videotron.ca> wrote:
<snip>
>I agree. However, do you consider deco diving to be "recreational"
>diving ?
>Also, if the times to surface during deco dives are so great, are
>Spare Air bottles of any use ?
Well, to quote Carl - they're great for a refreshing drink during the
stops ...
> In other words, in such dives, would
>Spare Air be considered at all ?
Not seriously :-)
Kenneth A. Smith
Dan Masi wrote:
>
> J Shepherd wrote:
>
> > I would maintain that a SA has enough air to get you to your
> > buddy or the surface only under such a restrictive set of cirumstances
> > as to be practically useless.
>
> Here's my situation, tell me if you think it's useless. I'm chartering
> a sailboat in the caribbean. I'm anchored in a small, sheltered bay
> that generally always has a few sea turtles hanging around. My buddy
> feels like lounging on the deck with a book, I feel like saying
> hi to the turtles. Vis is 60 to 100 feet, sunny... the bay's like
> a flat lake. Bottom is sand at 25-35 feet. I'm not gonna dive
> without SOME kind of redundant air source. If I limit my depth
> to 30 feet, do you still agree that my SA is useless?
At 30 feet you can take you last breath and head for thesurface, no
safety stop unless your using Quad 120's.....SA is still almost
useless....
Ken
KybrSose
Jason,
1. I dont plan to run out of air; I plan against it.
2. I try to never assume
( that whole ass of u and me thing gets me every time<G>)
This includes never assuming my buddy can cure all ills.
What do you do if your buddy cant help you?? if he freezes?? if hes
too narced to solve the problem?? If seeing me entangled freaks him sooo
that he ....?? If I can breath on my own I feel better about most
everything else. Maybe its just me.
As far as mucking with multiple tanks , whats sooo horrible about a 13
cu. pony on a releasable harness?? A 26 or a 30 can be bulky but a 13 aint
much bigger than those damn spare airs.( in size capacity is obivously ten fold)
In any event I think we can agree to disagree; there aint much more to
say without bashing each other here.
Safe D.
Al Marvelli