RDP vs eRDPml vs Dive Computer

[lowviz]

...//....So, which one is more correct? ...//...

G of course. That is how you use tables.

I'm not trying to warp tables into a higher degree of accuracy or precision. OK you easily extracted two group letters from your graph. -do you now see that this gave you a really good way to show the "superiority" of a dive computer over tables? (personally I prefer the safety margin given by tables, but another topic for another day)

Isn't a direct graphical comparison at this level much more comprehensible to an OW student than someone spouting why this or that is better? I say your direct graphical comparison makes both tables and computers more understandable.

...//.....wouldn't it be better to teach students the meaning of compartments, half times and pressure gradients instead of teaching them how to use a table - or some other similarly limited and discrete devices?...//.....

No, way too much for OW.



You asked where the NOAA conversion was:

This will generate a number that corresponds to the letter of the alphabet, round to 1 place so you can appreciate "fractional" letters.

http://www.scubaboard.com/forums/te...microbubble-stops-shortcut-2.html#post6195135

 

[DevonDiver]

No, way too much for OW.

Agreed 100%. Most Divemaster candidates I know struggle to pick that stuff up quickly.

 

[DiveNav]

.....Isn't a direct graphical comparison at this level much more comprehensible to an OW student than someone spouting why this or that is better? I say your direct graphical comparison makes both tables and computers more understandable. .....

I am glad to see you writing so.
That is why we designed divePAL in the first place.

I will see if we can add pressure groups in the next rev. Since we are already computing a running depth average, it should be quite straightforward to spit out a letter using some look-up tables.

I can't believe I am going to add "tables" to divePAL .... but if this helps my fellow Instructors I will gladly do it.

Alberto (aka eDiver)

 

[lowviz]

...//....... but if this helps my fellow Instructors I will gladly do it. ...//...

(-just to be clear, I fall into the student category not an instructor.)

Really interested in your next rev if you add PG's. I still like my Uwatec SmartPro for NDL diving, would very much like to see how badly I'm getting "spanked" for using tables on various old profiles.

I'm assuming that any past dive in the DC can be analyzed???

Best,
lowviz

edit: I just looked at your site and noticed only SP Aladin and Sol are supported. Not interested in bells and whistles, any way to get SmartPro into a form you can use. Failing that, do you have a "generic" input format?


Matt: I hope that you don't see this as a hijack, I think that it speaks directly to your OP.

 

[rhwestfall]

Do you remember which set of conservatism where you using in divePAL?

it was before it was adjustable.... maybe I can find when I had posted it (date) in a discussion about some ML profile thoughts back a bit ago....


Edit: here is one where it was close.... there is another...
http://www.scubaboard.com/forums/basic-scuba-discussions/397314-dive-computer-3.html
also sometime before 10/12/1011 because I commented here....

http://www.scubaboard.com/forums/basic-scuba-discussions/399060-diveplanner-2.html#post6080968

 

[rhwestfall]

(-just to be clear, I fall into the student category not an instructor.)

Really interested in your next rev if you add PG's. I still like my Uwatec SmartPro for NDL diving, would very much like to see how badly I'm getting "spanked" for using tables on various old profiles.

I'm assuming that any past dive in the DC can be analyzed???

Best,
lowviz

edit: I just looked at your site and noticed only SP Aladin and Sol are supported. Not interested in bells and whistles, any way to get SmartPro into a form you can use. Failing that, do you have a "generic" input format?


Matt: I hope that you don't see this as a hijack, I think that it speaks directly to your OP.

If your unit can export a DAN file, you may be able to use it as a method to bring it in to Alberto's program... (just saying....)

 

[DiveNav]

....I'm assuming that any past dive in the DC can be analyzed???....

Yes.

..... do you have a "generic" input format?...

the current version of divePAL support import of native logbooks generated with Aeris, Suunto or Oceanic programs. Additionally, it can import logbooks in DAN format.

Next version (ETA end of February) should support import of logbooks geneared with Mares and ScubaPro programs. It should also support direct import from some dive computers.

Alberto (aka eDiver)

 

[rhwestfall]

oh if only that company out of Texas would play friendly......

 

[Bubbletrubble]

During my recent Advanced Open Water certification, we did a multi-level dive, and charted it using all 3 devices: RDP, eRDPml, and dive computer.

• According to the RDP, I should have been dead.
• The eRDPml permitted the dive, made a lot of sense to me, giving me dive groups at each stage.
• The dive computer permitted the dive, but gave no dive groups.

So I liked the eRDPml best, but I can see that it's not as accurate as the dive computer in figuring out your precise no-decompression limit.

How do you log your dive if you used a dive computer? Do you just leave off the dive groups from the log book?

@Matt Beckwith: Although the discussion has gone off on several tangents, I'll try to address some of your initial questions...

All of the modern dive computers which I've encountered automatically track nitrogen loading in the post-dive interval. As the surface interval increases, the diver should note that the NDLs for subsequent dives will also increase...up to a certain level.

Entering the "dive plan" mode during a surface interval will reveal allowed NDLs for a given depth on the next dive. At most dive destinations, the DM/boat captain will plan for roughly a one-hour surface interval. Before splashing in, divers will take note of the NDLs for the planned max depth of the upcoming dive. During the dive, people will watch their dive computers and make sure that, whatever profile they adopt, NDLs do not go past zero (i.e., enter "deco" mode). In practice, this is the extent of dive planning among the vast majority of recreational divers.

Lots of newbies ask how to log the pressure group for a dive conducted while using a dive computer. This question comes up because the PADI dive log is geared toward paper-based logging of dives conducted with dive tables. There's a special spot on each dive log page to enter the "pressure group." When making the transition to a dive computer, the novice encounters a head-scratching moment since most computers don't spit out a PADI-style pressure group after a dive.

As others have mentioned, the purpose of the pressure group is to track nitrogen loading. Since the dive computer is already automatically tracking your nitrogen loading, you'll be "OK" so long as: (1) you use the same computer on subsequent dives, (2) the computer continues to function properly, and (3) you do not violate the NDLs on subsequent dives.

If you feel so inclined, you can certainly "back out" table-equivalent pressure groups from your dive computer. No expensive software programs or mental gymnastics are needed.
Simply enter "dive plan" mode immediately after surfacing from a given dive.
You will see NDLs represented for various depths on subsequent dives. Take note of these numbers.
Cross-reference these numbers with the numbers on a dive table to come up with a pressure group.

For example, let's say you just conducted a computer-based, multi-level dive to a max-depth of 70 fsw with a run time of 60 minutes.
(N.B.: The standard PADI RDP tables wouldn't allow such a dive since a square profile is assumed.)
Upon exiting the water, you enter "dive plan" mode and see that you are given the following NDLs/depths: 67 min at 40 fsw, 28 min at 50 fsw, 14 min at 60 fsw, and 6 min at 70 fsw.
If you reference the back side of your PADI tables, you'll see that this series of NDLs/depths is roughly equivalent to pressure group Q.
Theoretically, you could use this pressure group to approximate the nitrogen loading "credit" you would earn during the surface interval. You would note that after a one hour surface interval, your pressure group would be F.

 

[Ben Prusinski]

I learned to use all three and good to understand tables. Did not care for the eRDP which is a pain to use and not that great. Hands down, love using dive computer as its easy to set and use on a dive.