i can't remember NUAI tables that went that daep - but the Nave tables
allowed it ( if i remember right ). a dive to 200ft for 5 min and useing
the then 60ft/min ascent rate brought you out well under the NDL, even
useing todays more rigid Mvalues and 30ft/min you're still "safe" - as
far as deco is concerned, but pushing it!! only the 2 fastest
compartments are above 90%.

40 years diving - DM.

The old Navy tables that I remember from around 1980 gave a 5 minute time
for 190 ft... I think the ascent rate was assumed to be 60 fpm back then on
the Navy tables... I suspect that we ascended faster than 60 fpm though...
The concept of a safety stop didn't seem to exist either...

I am not a professional diver and I am don't know a damn thing
about old Naui standards, but I am "old enough" ... 1 out of
3, is that good enough?  :-)

I dunno and I duncare what Naui charts at one time in the near past
stated.

But I DO know that a 5-minute bounce (that's all it is) on air
is not gonna put any dent (or bent) on anyone, especially on
an slow ascent with a safety stop.

A computer dive to 200 ft max (well actually 199 ft) on
the latest version of the ORCA air-dive-computer algorithm is
a no-deco air dive if you spend the rest of a 20, 30, 40, 50,
or 60 or more minutes (subject to your air consumption on a
80 AL tank) of a regular 1-tank dive on a typical boat dive in
Cozumel at 80 or 90 fsw max, or any liveaboard dive (back to
boat with minimum 500 psi) if you take away the max depth xxx ft
constraint).

The ORCA goes "out of range" at 200 feet -- which is the only
reason I mention 199 ft.  Done MANY no-deco dives on the
ORCA air computer below 200 ft too, but that's another story.

People quit using the cliche "there are bold divers and old divers
but no bold and old divers" on me.  :-)  

I am a SELF-RELIANT, and SELF-RESPONSIBLE, old diver.  That's it.

What was your question, again?  :-)

Oh, I remember now, "without additives to a tank".   Do you mean
STP or other high-detergent additives in the tank of gas used by
the boat?  :-)))  I wouldn't know.  YOu would have to ask the
boat captain.

BTW, I once forgot to reset my Uwatec Nitrox dive computer from
EAN 32 to air (EAN21), and did a dive to 196 fsw (I always
carry an ORCA air computer on all my dives), and even that
terribly conservative Buelmann Algorithm of the UWATEC didn't
complain about that dive, and kept on ticking in the no-deco
air dive.

Sorry, that's all I can tell ya.  No Naui, no additives, no
DIR, no GUE, and no other alphabet soup either.  Just plain,
sensible (having read plenty of books of diving physiology,
dive computer algorithms, and diving physics though) diving.

I am a living diver of many deep-air dives.  Never been bent either.  
That's my relevant qualifications.

I walked to the Cozumel
chamber once for diagnosis after experiencing some subclinical
bends symptoms after diving 20 consecutive days to max below
195 fsw on air "without additives" :-)  and was sent out by the
chamber physician without even any chamber ride for diagnosis.
Story told in rec.scuba on a dive computer related thread.
Use the archives to read the details.  Don't have the time to
point to the exact post.  Gotta get a good sleep before embarking
on a long diving related trip.  :-))

Flame away, for those who don't know better.  :)

HYDRATION and plenty of REST ... as COnfucius always say on diving.

-- Bob.

The NOAA Diving Manual (1977), lists the USN Table for 200fsw as:

5 min ... 1 min @ 10fsw                    Total ascent time  4:20
10 min ... 1 min @ 20fsw + 4 min @ 10fsw.   Total ascent time  8:20

John Lipppmann's Deeper Into Diving (1990), lists the same values.  
There are no times shorter than 5 minutes listed that would allow a
complete direct ascent.

For reference, the 1983 DCIEM Table calls for 4 min @ 10ft for a 5 min
bounce to 200fsw.  Several other tables cap out at 54m for air and thus
do not even reach 200ft to be applicable.

My recollections are that the early NAUI tables were just relabelled USN
Tables (it was only later that they started to slip groups to make the
no-stop times more conservative).  As such, I'd have to say that a 5
minute 200fsw bounce has to have required at least the 1 minute stop
since at least 1977.

-hh

Hi John. Although I hate to admit it, I'm old enough to remember the
standards to which you refer. However, there were no "NAUI charts"
back then. There were no PADI "charts" either. In fact, the agencies
back then did not even have their own teaching materials. Dive shops
had their students buy books / instruction manuals that were written
by 'experts in the field' at the time and the standard that was used
was the "US Navy Air Decompression Tables."
We were taught to dive without using a safety stop and our ascent rate
was to be no faster than 60 ft per minute. (Safety stops are now
recommended and the ascent rate being taught today is 30 ft per
minute.

To get specific with re: to your question about standards... yes, 200
ft for 5 mins on air was ok for a no-decompression limit dive. The
following are the actual times from that era :

60 ft = 60 mins
70 ft = 50 mins
80 ft = 40 mins
90 ft = 30 mins
100 ft = 25 mins
110 ft = 20 mins
120 ft = 15 mins
130 and 140 ft both = 10 mins
150 thru 190 ft were all = 5 mins

I'm not a 'professional diver'... I'm just someone who made my first
dive in 1978. My qualifications are PADI training, and more recently
NAUI.

Depends on what you mean by "allowed". Prolly the most aggressive tables
ever published were the 1907 Admiralty tables which allow, at 192-204
fsw, up to 12 minutes with a deco obligation of 3 minutes at 60', 3
minutes at 40', 7 minutes at 20', and 10 minutes at 10' Most of the
tables that go that deep are a bit more conservative, though not a lot.

Those of us who have done a bit of deep air (Oh, the horror! Oh, the
slap in Darwin's face that we survived!) ran schedules along those
lines, which works out well with a steel 72.