PADI vs NAUI dive tables

[Backtanner]

I'm gearing up to take the PADI AOW next week and am freshening up on dive tables. I was originally certified thru NAUI and this is my first experience with PADI. My question is are the dive tables the same?

 

[-hh]

Short answer: probably not.

There have been a million different permutations of the old USN dive tables over the past 20+ years and the only safe (and correct) thing to do is to make sure to read all of the fine print (the infamous PADI XYZ rules, etc) that go into each table implimentation so that you know what its assumptions and restrictions are.

Thus said, they do still all operate in roughly the same fashion for how to look up bottom times, surface intervals, residual nitrogen, etc, etc, so if you really know your way around the NAUI table, it should be downright trivial to adapt to using the PADI Table, etc.


-hh

 

[Backtanner]

Thanks, I am trying to get used to the "flip side" of the PADI tables.

 

[crispos]

I'm gearing up to take the PADI AOW next week and am freshening up on dive tables. I was originally certified thru NAUI and this is my first experience with PADI. My question is are the dive tables the same?

No they aren't in several respects.

They are based on different models. I believe NAUI tables were derived from US Navy Tables but PADI was developed much later based on a Spencer-type model. Please check me anyone on this.

The pressure groups are quite different. NAUI goes from A to L whereas PADI goes from A to Z. So you can't both be L divers and say you have the same saturation. This is the most important difference in my mind, because you might (but should never) switch tables during a surface interval with unforeseen consequences, especially going from NAUI to PADI.

In addition, the NAUI tables gives emergency decompression stop times at 15 feet for various NDL violations, for example an 18 minute stop if you go to 90 feet for 50 minutes. PADI has a 2 type rule, for exceeding NDL by 5 minutes or more than 5 minutes.

In NAUI, a repetitive dive is cleared in 24 hours whereas in PADI it is 6 hours. PADI's time to fly was lower (12 hours) but has since been raised to 18 hours for repetitive diving. NAUI is 24 hours if I recall.

The NDL's are slightly different. Many people think the NAUI tables must be more conservative than PADI but actually it is only at the 100 ft to 130 ft depths. At 70 feet NAUI has an NDL of 45 minutes and PADI has 40 minutes. At 80 feet, NAUI has 35 minutes and PADI has 30 minutes.


All the best.

 

[Walter]

If you can use one, you can use the other. They work exactly the same way.

OTOH, PADI's tables are much more liberal for repetitive diving. If you want a conservative table, look elsewhere. When PADI came out with the RDP in the late '80's, it was very conservative for single dives, but very liberal for repetitive dives. Since then other agencies have trimmed back their NDL's. Now the RDP is one of the most liberal tables around.

Many people think the NAUI tables must be more conservative than PADI but actually it is only at the 100 ft to 130 ft depths.

Not exactly, although close. NAUI is more conservative at 30 ft, 110 ft, 120 ft & 130 ft. The RDP is more conservative at 70 ft, 80 ft & 100 ft. They are the same at 50 ft, 60 ft and 90 ft. Of course that assumes there will be no repetitive diving involved. If there is, the RDP quickly become much more liberal.

If you're looking for conservative tables, check out DCIEM. They have the most conservative tables I've examed. They don't have the same format as most others. The most conservative tables (overall) with the same format as NAUI & the RDP are the YMCA tables.

 

[IndigoBlue]

PADI tables are unique. If you use them, you need to stick with them, and you cannot use the same letter groups to switch over to any other tables such as to NAUI or to USN.

With traditional NAUI tables, you are basically getting USN table data, except for 2 differences:

NAUI has reduced their NDL times compared with USN, and

NAUI uses 24 hour repetitive dive times compared with USN.

These tables are now called "NAUI USN-based tables" since NAUI recently came out with a batch of totally revised RGBM NDL Tables, which look completely different from any dive tables heretofore.

In the traditional NAUI USN-based tables, the NAUI letter groups are the same as the USN letter goups. This is helpful, whenever you are using any of the NOAA tables from the NOAA Diving Manual, like time before ascent to altitude, or surface interval planning, or altitude diving, or NOAA-USN letter groups for diving shallower than 40 ft.

So to answer the original question, NAUI and PADI dive tables are read in a similar fashion, although the information they give are completely different and not interchangeable between the two.

 

[CRDiver]

NAUI recently revamped their dive tables - for both rec and technical programs - using the RGBM model. They're quite different from PADI, YMCA, and the old NAUI tables.

 

[MB]

NAUI recently revamped their dive tables - for both rec and technical programs - using the RGBM model. They're quite different from PADI, YMCA, and the old NAUI tables.

NAUI has added another set of tables based on the RBGM, but they have not replaced the previous tables. The two sets are quite different, and apply to different types of diving conditions. For example the "new" tables assume a surface interval of 60 minutes or more. This is quite reasonable for picnic table surface intervals with BBQs, visits among friends, etc - common at lakes, springs, etc. But on dive boats with shorter SIs, the RBGM tables aren't very practical. That's why NAUI has two sets of tables (did not simply replace the old with the RBGM tables).

As for the differences between padi tables and NAUI tables, an important distinction also involves when the diver stops the clock. NAUI tables are based on the dive clock stopping when the diver hits the 15' safety stop. The padi tables use a different assumption - table time ends when the diver leaves the bottom for a direct continuous ascent to the surface (or safety stop).