Tables for DIR.

[Jasonmh]

Most of the dives in DIR-F are in shallow water (20-25 feet max), so NDL is not really an issue.

...

Very true, in ours the max was 40 feet, although most of the dives rarely went below 30ft.

 

[limeyx]

Very true, in ours the max was 40 feet, although most of the dives rarely went below 30ft.

Interesting. I assumed the poster wanted to get familiar with the tables taught in the class, not the deco profiles for the dives during the class itself.

Could have been meant either way I guess.

 

[rongoodman]

It turned into an interesting thread. I printed up a set of the Minmum Deco tables and got them laminated today, and went over the new instructions for them. I'll leave any further worrying until class. Thanks for the feedback.

 

[Jasonmh]

Interesting. I assumed the poster wanted to get familiar with the tables taught in the class, not the deco profiles for the dives during the class itself.

Could have been meant either way I guess.

I assumed the same, I just threw that in as a side note, based on DIR-Atlanta's comment. Just to say that the OP will be taught the table in class, but that there is not alot in the class itself that requires the use of the table. Hope that didn't confuse anyone.

 

[limeyx]

I assumed the same, I just threw that in as a side note, based on DIR-Atlanta's comment. Just to say that the OP will be taught the table in class, but that there is not alot in the class itself that requires the use of the table. Hope that didn't confuse anyone.

Right. One thing that I noticed when I saw a copy of the "new" powerpoint charts is that they seem to have different ascent profiles for 32% compared to 30/30.

From 100 feet, 32% seems to be stops at 30, 20,10 and 30/30 has what I would expect 32% to have - stops starting from 50 feet.

Definitely a bit confusing.

 

[Dan Gibson]

Unless something has changed recently or there is a misprint in the powerpoint, there is no difference in the way 30/30 and 32% are treated. This is what was taught back in '03 during my cave classes:

Dives 90-120 ft First stop at 50' off bottom
Dives 0-80 ft First stop at 40' off bottom
Deeper dives First stop at 80% of max ATA.

Right. One thing that I noticed when I saw a copy of the "new" powerpoint charts is that they seem to have different ascent profiles for 32% compared to 30/30.

From 100 feet, 32% seems to be stops at 30, 20,10 and 30/30 has what I would expect 32% to have - stops starting from 50 feet.

Definitely a bit confusing.

 

[limeyx]

Unless something has changed recently or there is a misprint in the powerpoint, there is no difference in the way 30/30 and 32% are treated. This is what was taught back in '03 during my cave classes:

Dives 90-120 ft First stop at 50' off bottom
Dives 0-80 ft First stop at 40' off bottom
Deeper dives First stop at 80% of max ATA.

This is basically what I use (50% of depth for recreational dives, 80% ATA for tech)
I think it might have been that they treated Rock bottom differently for each gas (not wanting to bring you up too fast on the Helium).

Maybe the "standard" ascent profile was the same. I am not 100% sure because I just saw them for a moment -- my tech1 buddy was all kinds of confused about why the different profiles etc.

And to the person who laminated the tables -- make an effort to memorize them (and the pattern that they form) -- that's the point of this simple table, after a few dives it should be in your head so you can throw the paper away and still go diving.

This technique scales up to dives at the tech1 and tech2 level for a considerable range of diving (although there may be certain dives that fall outside the useful range)

 

[RTodd]

I'm getting ready for DIR-F in a a couple of weeks and it just struck me that I don't know what they use for tables for NDL diving. I have the PADI tables for air and Nitrox and DPlan on my Palm, but what do they want me to have in my pocket during dives?

As previously stated, a proper DIR-F class will be in the 15-20' range where maintaining bouyancy is more difficult and the importance of this basic skill when performing other tasks is more evident. As far as what you will learn in class, to the extent much deco theory is taught at all, pay attention to the theory. The tricks people use are infinite and while some, such as the tick tac toe/ deco on the fly method, are slightly more robust, they all suffer from being limited to very specific depth and time ranges that you need to understand before using them.

As a result, knowing the DIR approach is more important. And, it is my belief that cutting a whole bunch of tables on decoplanner or similiar software and modifying it using the basic DIR deco philosophy is a far better way of truly understanding this stuff than learning the shortcuts off the bat because you start to see where the patterns come from. All of that was a lead in to point out that, while the posted tables work, they appear to use massive minimum deco overkill in order to account for a limited number of multi-dive scenarios that could put you in a slight amount of "true" deco. Understanding where that line is would be far more helpful than just using these tables.

 

[Robert Phillips]

I also just noticed that Peter put up an article on how to use the minimum deco tables yesterday!

http://dir-diver.com/en/knowledge/min_deco_table.html

The article is not new, he just changed the url and added a link to it finally. It used to be a secret page that you had to do some research to find. I checked my old link and it is no longer active. Thanks for posting the new one!