Past NDL. And then this???

[Asteve]

My mistake it 25 feet for 595 minutes, https://www.dir.ca.gov/oshsb/decompressionAC-USNdivetables.pdf

 

[admikar]

Ladies and gentlemen,

The horse (OP) is not dead as yet and ready to be beaten AGAIN (maybe I’ve started enjoying it).

I did look at all “official” resources I have about emergency decompression procedures (as PADI calls them).
Here is the list with a brief description of the procedure on each:
- PADI OW manual: If a computer is used, follow the computer. If a table was used follow the procedure described in the table.
- The PADI OW tables: If NDL elapsed by up to 5 mins, 5 minutes deco stop at 3-5 meters, if NDL elapsed by more than 5 mins then 15 mins deco at 3-5 meters (no word on calling the dive or min rate of ascent).
- My Computer’s manual: it only describes what is shown in the screen. Not what/how to do. Yes there is a TOTAL time (including ascent time) but that is an “indication” as clearly stated. Neither a requirement nor even a suggestion!

My question: based on the above, how am I (or any other newbie diver) supposed to know that once in emergency deco, I should ascent ASAP to deco?? Is it just too obvious to everybody else but not me? In that case please beat me, hard!

Through the discussion, and thank you all for this, it is now clear. But how the heck was I supposed to know that before the incident? Since it is so vital, shouldn’t it be mentioned clearly in the manuals? Eg In case of emergency deco, call the dive and ascent as soon as possible (<10m/min) to the first deco stop following your computer’s instructions.

Please hold on beating for a sec – I promise you (I) will get more soon.

Now something else, very important for fellow newbie divers with Leonardo (and maybe other Cressi computers) to observe!

As discussed in another post my computer has an ascent rate indicator. Up to 3 arrows are displayed: one arrow for 4-8m/min ascents, 2 arrows for 8-12m/min and 3 arrows with a beep alarm for >12m/min. So far, so good. The problem arises when the dive is imported to Subsurface. Cressi records all of these as “type=3” events, i.e. warnings. Hence all these ascents (1, 2 or 3 arrows) are marked as warnings (yellow triangles) in Subsurface! Yes an ascent rate of let’s say 4m/min is reported as a Warning in Subsurface!

Prepare your canes – beating time approaching.
Believe it or not, silly me, all this time, this has led me to assume that even a single arrow ascent (4-8m/min!) is to be avoided.
Beating can now start again.

All I hope is that this post to reach as many (idiot?) newbie divers as possible to avoid all these silly mistakes.

Thanks once more...

Every theory pack of every agency at its back should have written in big letters: GO TO SCUBABOARD AND EDUCATE YOURSELF!

Not being in decompression and being shallow my Oceanics will give around 9 hours NDL. I always wonder if they would put me in deco after that.

If you ever do a test on that, would you mind posting your findings?

 

[Centrals]

Well, it depends on how soon the next dive is...

Even if the NDL reads 99 you will get shorter NDLs on subsequent dives unless you wait long enough to fully off gas. After each dive the surface mode provides 2 pieces of info: time to fly and time to desaturation. If you have a non zero desaturation time, the computer believes you still have tissue loading and will give you shorter NDLs.

I know our body can tolerate certain degree of inert gas saturation buy why the rush at the end of the dive eg. in joe10540's case which was after 15mins of deco obligation?

 

[KevinNM]

By sheer coincidence, I have been conducting a discussion with DAN about this. Here is the latest from them on the topic:
Alert Diver | Ascent Rates

It does not clearly pick a best between 30 and 60 FPM, but the full discussion seems to favor 30 pretty strongly. My quibble with this article is that while the wording STATES that the slower OF THOSE TWO is better, it IMPLIES that slower is always better, with no bottom to the options. It talks at length about the danger of going too fast without mentioning the danger of going too slow.

BTW, the impetus for our discussion was this thread. I am pretty sure that the consensus here is that the OP ascended much too slowly, and his apparent motivation for ascending so slowly was a mistaken belief that when dealing with emergency decompression, the slowest possible ascent is best.

See also
DAN | News

 

[KeithG]

See also
DAN | News

Be aware that the above linked blog page although created in 2011 contains content originally from 2004. The 2011 blog post comes comes with the disclaimer: "This article does not represent current thoughts about the subject. For more relevant information about the subject please refer to Deep Stops by Petar Denoble." which can be found here: Alert Diver | Deep Stops

 

[KeithG]

I know our body can tolerate certain degree of inert gas saturation buy why the rush at the end of the dive eg. in joe10540's case which was after 15mins of deco obligation?

It was lunch time?
It was nap time?
The boat was leaving?
My wife was yelling at me to get out of the water?
...

 

[Michael Guerrero]

Buy a Petrel or Perdix, problem solved.

 

[KeithG]

Buy a Petrel or Perdix, problem solved.

Which problem?

 

[Dan]

Which problem?

This problem?

 

[KeithG]

If you look at some of the latest dive tables you can not stay at 20 feet forever any more.

This triggered a thought: "the latest dive tables".

When was the last time someone came up with "new" tables?

This is also indirectly related to the question: When was the last time some one came up with a new algorithm? That has survived?