From: wall@hel4.brl.mil (Jeff Wall)
Newsgroups: rec.scuba
Subject: Re: Information about advanced deep diving course
Date: 3 Sep 92 14:30:28 GMT
Reply-To: wall@hel4.brl.mil (Jeff Wall)
Organization: U.S. Army Human Engineering Lab  Aberdeen, MD

In article <pc1nphg@twilight.wpd.sgi.com> story@sgi.com (David (Duis) Story)
writes:
>In article <BtytAH.GuD@apollo.hp.com> daigle@apollo.hp.com writes:
>>
>>I have a question about this that has been bothering me for quite some time
>>if anyone would care to comment on it.
>>
>>
>>What I want to know is why PADI does not teach you what to do if you blow
your NDL.
>>What would be wrong with them teaching some light decompression diving?  
>
>PADI and DSAT created the definition of "recreational diving" which
>you see bandied about so much lately.  The definition was created
>purely for the sake of defining what profiles the DSAT "Recreational"
>Dive Planner could cover.  That definition is "<130fsw, repetitive,
>no-decompression diving."  This definition was necessary in order to
>use a shorter half-time (60 minutes vs 120 minutes) which allows
>"recreational divers" a LOT more bottom time because it assumes you're
>offgassing more quickly than the US Navy tables do.  This is a big
>sales advantage in PADI's eyes: an exclusive table that gives more bottom
time!
>
>From the day the RDP was released, PADI, a very-much-for-profit
>organization, began selling the PADI RDP tables.  All their training
>materials were rewritten to stop using the US Navy tables and to use
>the RDP.  Decompression was no longer discussed.  For various reasons
>including the fear of liability and desire to sell RDPs, decompression
>has become a taboo subject.  Since PADI currently certifies about 70%
>of US dive trainees, their word sets a big trend in the market.  Add
>to that their willingness to team with specific manufacturers to
>promote the DSAT model into dive computers which are then promoted by
>PADI, and you have a perpetual circle which leads to decompression
>falling off the map.  If you don't talk about it, it isn't there.
>
>>If I stay down too long (OK, I know, never let that happen), then I
>>am SOL when it comes to knowing what the hell to do now.  Saying that
>>I shouldn't have blown my NDL is simply not acceptable at that point.
>
>To be quite fair, PADI does allow single "emergency" decompression
>stops on their tables.  If you look at the special rules you'll see
>rules for 8 and 15 minute stops at 10fsw, if you've overstayed by less
>than 5 or greater than 5 minutes, respectively.  Of course you have to
>stay out of the water for 6 and 24 hours, respectively, which can put
>a crimp in your diving.


I've got a question that has been bothering me since I started hanging out at
the local dive shop which just happens to be a PADI store.  This dive shop
sells the Sherwood Source (a.k.a Oceanic Datamax) and I am under tthe
impression it uses the DSAT model. I this correct???

If this is correct how do they figure decompression??  I know for a fact (just
about everybody I dive with uses the Source) that the Source will allow a diver
a 40ft deco stop.  So, if the Source uses the DSAT model then it is
theoretically possible ( if PADI were so inclined) to do deco diving on the
PADI RDP.  Yes???  No???


>But don't use the RDP for planning decompression dives.  The RDP is
>simply not set up to handle decompression diving.  
>
>The table's limiting compartment loadings are all 93-99% of the Navy
>limits, and the controlling halftime (how fast you unload) is twice as
>fast as the Navy's.  That means that the RDP is LESS conservative for
>almost all repetitive diving than are the US Navy tables.
>
>The bottom line is that if you want training on decompression diving,
>you won't get it from PADI.  They're just not interested -- it hasn't
>been proven to them that it has sufficient return.

Jeff Wall
wall@hel4.brl.mil
Newsgroups: rec.scuba