Sounds great Popeye. In addition and since Janet says the dive shop is
"cheap", I'd take a gander a their pumping facilities.

SD

Janet wrote

I'll comment on your question and on Popeye's response.

The only mistake I see appears in the paragraph above.  You rented gear, but
did not inspect it until you reached a remote dive site.  This is a mistake
many of us have made and learned the hard way, as you did.  The time to
inspect and check your gear is while you can still do something about it.
In the case of rental gear, that inspection should happen in the shop you
rent it from.  Look the tank over, check the pressure, take a couple of
breaths from each of the second stages, confirm that the SPG is working,
that it starts at zero and that what it reads when fully on makes sense.
Check to make sure the inflator is not leaking either into the air or into
the BCD.  If there's something wrong, or something you don't understand, you
have a chance to get an explanation or a fix.
Had you done your inspection at the shop, you would have been able to do
your dive as planned.

Like Popeye said, you did the right thing.  The general rule is, if you
don't know what you're breathing or you don't know how to breathe it safely,
don't breathe it.  Like Popeye, I highly recommend a nitrox course.  Without
getting into the details, most divers find advantages to nitrox that makes
it worth the normally higher cost.  Even if you don't, and not everyone
does, the course will teach you things you should know about how the gas
side of diving works.  My nitrox course, as courses go, was awful, and it
was still one of the best post certification courses I've taken, and I've
taken more than a few in my 44 years of active diving.

I think I've seen the sticker you're talking about.  If, as you said, it's a
round sticker on the valve rather than the tank, it's not what Popeye
assumed.  They're not common.  All they are there for is to warn anyone that
fills the tank that it has been cleaned of flamible contaminants to the
point where it's safe to introduce pure oxygen into the tank at high
pressures.  One of several ways nitrox tanks are filled is called "partial
pressure blending".  Pure oxygen is introduced first, followed by air.  High
pressures of oxygen and a flamable contaminant are a potentially dangerous
combination.  Shops that don't fill nitrox don't always filter their gas to
nitrox standards, increasing the risk that some contaminant will be
introduced into a tank that will later be partially filled with pure oxygen.
The sticker really doesn't mean much.  As Popeye noted, there's usually a
second sticker, an inspection sticker, that will normally indicate whether
the tank is expected to be kept "nitrox clean."  It will be pretty clear
that the tank was been certified to be clean to O2 standards when inspected.
Inspections in the US are annual.  Even this sticker doesn't say anything
about what's been in the tank since the inspection.

Popeye mentioned that nitrox tanks should have a large nitrox band.  That
certainly used to be the case.  It hasn't been for quite some time.  My
tanks, for example, are all cleaned for nitrox.  Only two of them have the
bands Popeye is talking about and they only have them because those two went
on a trip where I was not sure the fill technician would remember what to
put in my tanks without the reminder.  My tanks remain clean because I make
sure they do.  I pay attention to where I take them for fills and, even when
they are filled with 21% (air), I ensure that the air is filtered to nitrox
standards.  My tanks are almost never partial pressure filled, but they can
be.

Here's a bit of extra information for you.  Techncially, nitrox is any
mixture that is nothing more than nitrogen, oxygen and trace gases.  Air is
nitrox 21 (21% oxygen).  In common use, we usually mean a mix that has more
than 21% oxygen.  The oxygen replaces some of the nitrogen, allowing a
longer no decompression time at the same depth than you would get with air.
Contrary to what the untrained often think, nitrox is not a deep gas.  Above
certain pressures, oxygen becomes toxic.  The higher the percentage of
oxygen, the shallower the maximum operating depth (MOD) is.  Without getting
technical, the MOD for air is normally considered to be about 187 feet (a
partial pressure of 1.4).  That's not taught in most entry level courses
because it's well beyond what entry level divers are expected to do.  Thanks
to a higher percentage of oxygen, nitrox has a shallower MOD.  The standard
blends, 32% and 36%, have a MOD of 111 and 95 feet respectively.  Both are
within depths many divers see.  If you don't know about toxicity, you don't
know to stay shallow enough to avoid it.

Normal recreational nitrox mixes, anything under 40% oxygen, won't hurt your
equipment.  Some divers, including me and several others here, occasionally
use mixes with considerably higher O2 percentges, 50 to 100%, for
decompression purposes.  These gases have a much shallower MOD and are not
normally recommended until the diver has training well beyond what most
recreational divers do.  At these kinds of pressures, the contamination
issue extends to the regulator too.  People that dive mixes of this type
usually dedicate a separate regulator for it and scupulously keep it clean.

Nitrox tanks from that shop may have had NITROX across the tank, but not
everybody's tanks do.  While it's quite possible that nobody ever noticed
before, but that does not change the fact that the stickers should not have
been on tanks that did not contain nitrox.  The fact that 300 divers didn't
notice the sticker speaks poorly for the 300 divers, not for the two that
did notice them.  The shop's response was bull.

Ignorance can be cured.  You've taken the first step.

Both you and the shop made a mistake.  Your mistake was waiting until you
reached the diveshop to look.  The shop's mistake was leaving the stickers
on tanks that did not contain nitrox.  Personally, I think they should have
refunded your money.  If they didn't, I would have opened the valves on the
tank to drain the gas that I had paid for and walked out the door, never to
return.  They would be royally pissed.  That, of course, is the idea.

You should be safe and you should be bummed in general.  This is not your
first bad encounter with the same shop.  You should consider whether they'll
ever get your business again.  You should also name the shop here.  Our only
defense against bad service is the word of mouth advertising we use to
identify the good and bad ones.  They gave bad service and deserve to be
associated with it.

Not wiser, just better education and more experienced.

The shop was wrong first.  The divers were wrong worse.

Absolutely.

Yes

Inspection stickers (VIP) aren't normally on the valve.

Yep.

I'm not sure why Popeye's proud 8^), but you should be.

This used to be the standard.  These dys, some do, some don't.  There's no
"supposed to" anymore.  Even if it does, the sticker is not a reliable way
to know what's in the tank.  If there's a question, any question at all, the
gas should be tested in the presence of, if not by, the person who will
breathe it.

I could not agree more.

Lee