Been to Koh Tao, should I go to PERHENTIANS?

morgand@cix.compulink.co.uk wrote:
> In article
> <{NOSPAM-rm_to_reply}rec-scuba2005-775AFF.06560825072005@news.giganews.com
> >, {NOSPAM-rm_to_reply}rec-scuba2005@huntzinger.com (H Huntzinger) wrote:
>
> > For mixes below 40%, the answer depends on how gullible you are in
> > regards to paying for stuff that you don't really need.
>
> Obviously we hav'nt fallen into the "gullible" trap yet then !!!!!

I guess neither of you have read my follow-up post to those,
raising the gullability bar on all.


> We have done about 500 dives since 98, most of those around the world in
> warm water and down to depths of 60m (in Chuuk), all this has been done on
> 12ltr singles and air,it has not caused us any concerns,

Well, you couldn't dive with EAN 36 down to 60m for long.
My Uwatec Nitrox Pro survived a 196 fsw bounce dive I did on air,
(can be found in the archives) because I had forgotten to reset it
to EAN 21. That fact didn't come out until one Crusty (whom I
had kidded for months about diving with a Cochran) noticed that
my Uwatec played dead the last dive of the liveaboard trip --
which was 10 dives after it survived the 196 dive, and the
CUMULATIVE effect of having done that dive finally caught up
with the computer algorithm.


> during intensive
> dive trips we dont fall prey to the "dive dive dive" routine, we prefer
> quality to quantity.........4 dives a day is usually plenty for us,

That sounds like dive, dive, dive to me! :) My all-time record
was only 7 dives in one day, but all shallow, when the Owner of
the Scuba-SE list, Jeff Kell the Trumpetfish, dived with me for a
week in Cozumel. doubling his lifetime total in dives.

http://tinyurl.com/9qqne

> and if
> we see dive times shortening because of overloading then we miss one and
> just chill for a while. So we ask ourselves "has it caused a problem, has
> it prevented us from doing what we wanted to do, do we need the extra
> hassle", no i dont think so. Air we can get freely at any dive center,
> nitrox is not available freely at all the dive centers we have dived with.

PADI has gone a long way from it's position of "no no" on Nitrox to
its present "yes yes". EAN is available in nearly ALL of the
liveaboards
I've dived the past 10 years (about 30?), and hardly on any before
that.

>
> I guess we wont get blown up just yet...........but.... farting underwater
> is'nt a hazzard is it ????????????

Only to the fish around you.

da Feeesh.
>
> Dave Morgan @ Work in the UK
> Take out the "goes diving" bit....
> Trip photos on line at www.morg.co.uk

"Lee Bell" <leebell@ix.remove.netcom.com> wrote in message
news:U56Fe.4435$6f.1433@newsread3.news.atl.earthli nk.net...

> Hugh's comments do raise an interesting point. If it's important to have
> a tank and regulator cleaned to O2 service standards for anything above
> 40%, O2, why isn't it important to have an O2 clean BCD and drysuit? Is
> the O2 somehow safer when shot through the inflator hose and into the
> BCD/drysuit than it is if shot through a regulator into your mouth?

Yes, it is somewhat safer. The main worry is not explosion, but carbon
monoxide produced from incomplete combustion. Obviously carbon monoxide is
more dangerous in your tank or reg than it is in your BC or drysuit.

Also, it's rare that someone will use more than 40% for their backgas. Most
often, the higher mixes will be used for decompression, breathed from a
stage bottle or pony that is not connected to an inflator hose, making the
regulator and the tank the only sources of worry.

If you are breathing 100% O2 and using the same gas to inflate your BC and
drysuit, I advise you to be very, very careful.

Now does anyone know if one's mouth and lungs have to be O2 cleaned before
breathing in pure O2?

On Mon, 25 Jul 2005 09:41:55 -0700, Greg Mossman wrote:
> Now does anyone know if one's mouth and lungs have to be O2 cleaned before
> breathing in pure O2?

Yes. It involves inhaling a gallon of Simple Green. As with all aspects of
technical diving, this requires specialized training. To prevent anyone not
trained in the correct procedure from being injured, I will not disclose the
details.

--
Art Greenberg

Art Greenberg wrote:
> On Mon, 25 Jul 2005 09:41:55 -0700, Greg Mossman wrote:
> > Now does anyone know if one's mouth and lungs have to be O2 cleaned before
> > breathing in pure O2?
>
> Yes. It involves inhaling a gallon of Simple Green. As with all aspects of
> technical diving, this requires specialized training. To prevent anyone not
> trained in the correct procedure from being injured, I will not disclose the
> details.

Good move, Art! Especially if you want to take a whif of Laughing Gas
while you are ROTFLYAO. The switching between Pure O-2 and Laughing
Gas involved very advanced technical diving training that only Trey
and other High Priests are privileged to talk about, let alone breathe.

-- Bob.

morgand@cix.compulink.co.uk wrote:
>
> Obviously we hav'nt fallen into the "gullible" trap yet then !!!!!

Congratulations.


> Seriously though.......its reading and listening to these kind
> of discussions where there are arguments on both sides that
> make me and my wife wonder and think "is it worth the hassle" ?

Personally, I think that it is 'worth the hassle' for some dive
profiles. However, by the same token, I also think that it is also
oversold at times too. The challenge is recognizing where and when it
is of value and ditto for where/when its not.

For example, I can recall a diver who was going to be going to the
Little Cayman resort that promotes the use of Nitrox. However, when
you look a bit more closely, you find that because the Resort runs a
2/AM + 1/PM tanks/day operation that routinely rushes the 2 AM dives so
that they can be back at the dock for lunch, the implications are that
these forced short duration AM dives would derive effectively no
"longer bottom time" benefit from the use of Nitrox.

Since the Nitrox wasn't free (IIRC, it was an additional charge of $12
per tank), it clearly was a pure waste of money for the consumer.
However, this doesn't stop the Dive Op from promoting it, since they're
the financial beneficary of the transaction.


-hh

"-hh" wrote

> Personally, I think that it is 'worth the hassle' for some dive
> profiles. However, by the same token, I also think that it is also
> oversold at times too. The challenge is recognizing where and when it
> is of value and ditto for where/when its not.

Or, sometimes, reducing the hassel to the point where it's insignificant.
When you and I dove, there was no hassel. I simply picked the tanks that
had a gas suitable for the dive we were planning. When we were done, I had
them refilled with the same. I normally keep a few tanks with 36% and a few
with 32%. The only time I don't have what I need is the rare occasion that
I'm planning to go beyond the MOD for 32%. Usually, it's no hassle at all.

Of course, if I'd known we were going to do the Castor and that Curtis was
going to bring doubles, you can be I would have arranged to use my 100s
instead of my 80s.

> For example, I can recall a diver who was going to be going to the
> Little Cayman resort that promotes the use of Nitrox. However, when
> you look a bit more closely, you find that because the Resort runs a
> 2/AM + 1/PM tanks/day operation that routinely rushes the 2 AM dives so
> that they can be back at the dock for lunch, the implications are that
> these forced short duration AM dives would derive effectively no
> "longer bottom time" benefit from the use of Nitrox.

That happens. On the other hand, many resorts allow unlimited shore diving.
It's possible that, even with the rushed boat dives, that nitrox would
provide some advantage . . . or not.

Resort diving is a tough question mostly because you almost always have to
pay more for nitrox. At home, I actually pay less.

> Since the Nitrox wasn't free (IIRC, it was an additional charge of $12
> per tank), it clearly was a pure waste of money for the consumer.
> However, this doesn't stop the Dive Op from promoting it, since they're
> the financial beneficary of the transaction.

Wow ! That's quite an increase.

The liveaboard boat I'll use next month charges about $50 extra fro 32% from
their on board membrane system. We normally do 16 or 17 dives over the 2
1/2 day trip. The combination of a very agressive dive schedule and
relatively low per dive cost make it worthwhile for me, but not by a lot.
Because my buddy does not use nitrox, I'm limited by his available no deco
time. What I get is the ability to stay deeper, which is my preference,
longer while he stays shallower, which is his preference. It works out for
us.

Then again, it was an air fill that was supposed to be nitrox, on the same
boat, that got me bent a couple of years ago. If you're going to be stupid,
which my failure to check my gas every time was, you have to be tough. My
damned elbow still bothers me.

Lee

In article <LCcFe.9108$oZ.8763@newsread2.news.atl.earthlink.n et>,
leebell@ix.remove.netcom.com says...
> > Also, it's rare that someone will use more than 40% for their backgas.
> > Most often, the higher mixes will be used for decompression, breathed from
> > a stage bottle or pony that is not connected to an inflator hose, making
> > the regulator and the tank the only sources of worry.
>
> That's a good point that I didn't consider.

There's a big difference between the 3000 PSI and possible supersonic
velocity that the first stage and tank are subject to and the 140 PSI
(maybe 160 if you have a Scubapro reg) that the BC, drysuit and second
stages see.

Lee Bell wrote:
> "Steve Kramer" wrote
>
>
>>>>Besides, if your BC isn't O2-cleaned, it can spontaneously explode
>>>
>>>So on a muli location trip and where one operator where you dive does not
>>>have nitrox your kit would have to be "cleaned" before you could go on to
>>>your next location where they did do nitrox ???????
>>
>>Not quite. HH is having you on a bit. But only just a bit. When using a
>>HIGHER than 36% O2 mix you are supposed to be using a cleaned tank and
>>regulator (NOT BCD...) Some people believe that the % can be much higher
>>before requiring specially cleaned gear. For safety sake, most people
>>with whom I've dived will only use 36% and below with their regular kit.
>
>
> In this part of the world, the arbitrary cut off is anything above 40%.
>
> Hugh's comments do raise an interesting point. If it's important to have a
> tank and regulator cleaned to O2 service standards for anything above 40%,
> O2, why isn't it important to have an O2 clean BCD and drysuit? Is the O2
> somehow safer when shot through the inflator hose and into the BCD/drysuit
> than it is if shot through a regulator into your mouth?
>
> Lee
>
>
The reason you have to clean a tank is because many shops use the
partial pressure method of filling. First they fill with pure oxygen,
then they add air to get (theoretically) to the desired mix. It's that
pure oxygen that requires tanks be cleaned. Your regulator isn't going
to see pure oxygen so the 40% limit applies.

Greg Mossman wrote:

[SNIP]

> Also, it's rare that someone will use more than 40% for their backgas.

I don't think I've ever seen anyone use more than 40% in their main
tanks. The only place I've seen it has been in stage tanks used for
deco, and those weren't hooked up to the BCD. But then, I don't spend
that much time with tech divers.

> Now does anyone know if one's mouth and lungs have to be O2 cleaned before
> breathing in pure O2?

Yes, but you can do it with cans of 'RediWhip.' :o)


Steve Kramer
"PhotoEnvisions" Freelance Photography
Chiang Mai, Thailand
http://www.photoenvisions.com
--
"The voyage of discovery lies not in seeking new horizons, but in seeing
with new eyes." - Marcel Proust

Lee Bell wrote:

> the shop that does my fills gives me anything from 21% (clean air) to
> 100% for a lower net cost to me than what I would have to pay for air at
> some shops. They do this by charging me by the cubic foot rather than by
> the fill. My tanks are rarely less than 1/3 full.

You'd better hope that they never figure out that it costs significantly more to pump
the last 1/3 than the first 1/3.

--
Steve

The above can be construed as personal opinion in the absence of a reasonable
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