Deco Terminology - call for discussion

[Joe Ross]

I agree.  I just meant to suggest, if a different term was going to be considered, it should be one that is in use within the industry.

As far as decompression is concerned, PADI's point is that a slow ascent rate IS your deco obligation, but they don't come out and call it that (in their instructional materials) either.  Bottom line is everybody knows what "no deco" and "NDL" mean anyway.  - Joe

Sent from my iPad

> On Feb 12, 2014, at 12:03 PM, Linus Torvalds <torvalds at linux-foundation.org> wrote:
> 
>> On Wed, Feb 12, 2014 at 10:44 AM, Joe Ross <joe at joescuba.com> wrote:
>> I don't know if it's my place to weigh in here, but as of 2014, PADI is
>> using the terminology "no stop" dives, since all dives are, in fact,
>> decompression dives.
> 
> I've seen that "all dives are decompression dives" being repeated a
> lot in "newer" literature, and it is, in my opinion, way more
> misleading than "no deco" ever was.
> 
> Many (most?) recreational dives literally *never* have a ceiling. It's
> not that they are "decompression dives without any mandatory stops".
> They simply don't involve tissue pressure differentials that are high
> enough to matter for human physiology unless you have other issues.
> 
> And the fact that you have a tissue pressure differential at all
> doesn't just magically make something a "decompression dive".  It
> really doesn't.
> 
> Put it this way: would you ever say that "all flights are
> decompression flights"? No, you wouldn't. A decompression event during
> a flight is something very clear, and it does *not* make all other
> flights "decompression flights" just because the normal cabin pressure
> may be 75% of normal or whatever. Or does anybody talk about
> "decompression weather" when the ambient pressure drops? No, they
> don't. We don't talk about "decompression elevator rides" either.
> 
> I personally think "no deco", "no stops" and "recreational diving" are
> all exactly the same thing - and they mean what people *intend* it to
> mean.  Language is more like what Humpty Dumpty described in Alice in
> Wonderland than people sometimes try to claim. There's no reason to
> try to claim that one naming is "more correct" than another.  And I
> claim that it is actively *incorrect* and misleading (despite all the
> PADI/SDI/whatever course books and videos that do it) to claim that
> "all diving is decompression diving".
> 
> As far as I can tell, "no deco" is still the common use. And "no
> stops" (or, as mentioned, "recreational") would be equally correct,
> but I think "no deco" is certainly the common one, and "NDL" in
> particular is certainly the normal short-hand for how much time you
> have left. I've never heard anybody ever say "no stop time", although
> I'm sure the "no stop" people are trying to make it a thing. Has
> anybody ever seen "NST/NSL"?
> 
> So I would suggest we keep to "no deco" and "NDL" because it's the
> common use phrase. Having the alternatives mentioned in
> explanations/docs migth be fine, but let's not make it show up in
> actual subsurface use.
> 
>                  Linus