Nitrox tables going too?

[TMHeimer]

The teaching of computer and/or tables has been discussed at length. I've heard of shops now teaching the nitrox course with computer only (to "save hours of learning tables you will never use"). Tables, even the nitrox ones aren't that hard if I could do it easily. Just memorizing how to do it. So what is the idea behind this? I assume shops just figure everyone will get a computer, and one that does nitrox (guess most do now anyway). If the computer fails, as with air, you just end the day's diving with no table backups. Or, you buy another computer as a backup, as opposed to a $30 watch and considering your dive when the computer failed as a "deepest depth one level dive". Is it about selling more computers?

 

[retro-steve]

To me it seems like a good business model if you are a dive shop teaching the course. Teach it so that students learn computer only and then offer them a discount on a computer only valid while they're doing the course, this way you get them to impulse buy it to get the deal, or make money down the road as they rent, get frustrated and eventually buy.

 

[Brendon]

The teaching of computer and/or tables has been discussed at length. I've heard of shops now teaching the nitric course with computer only (to "save hours of learning tables you will never use"). Tables, even the nitrox ones aren't that hard if I could do it easily. Just memorizing how to do it. So what is the idea behind this? I assume shops just figure everyone will get a computer, and one that does nitrox (guess most do now anyway). If the computer fails, as with air, you just end the day's diving with no table backups. Or, you buy another computer as a backup, as opposed to a $30 watch and considering your dive when the computer failed as a "deepest depth one level dive". Is it about selling more computers?

Sad to hear they are not using the table's anymore... I dont know how many times I've used Equivalent Air Depth with Nitrox, which still requires using the tables. I still use my NAUI and Navy Tables... Yes I own several computers, and have had all of them fail on me at some point. You know, I for one have never had to abort a dive because of it... Check my tables...Set my watch... Who care's if my computer goes, I know how long I've been down and my deepest planned depth recorded with the corresponding time limit on my slate. Still follow the old saying "plan your dive dive your plan". I doubt most do that this days. I am very happy to say that I am part of an organization that still teaches the tables!! Computer or not NAUI says you must learn the dive tables. I believe its for good reason. I'm sure before I die they will come out with an autopilot POV... It will be called the AQUA LAZY BOY

 

[smurf doc]

In my PADI class the instructor taught the eDPRML (or some similar acronym). Basically an electronic table that does calculations for you. It was a little annoying initially but very easy once I learned how to use it.

So I believe what Brendon said. If you know your depth when the computer fails, and you've calculated your limits before you dive, then a computer failure is just a minor annoyance.

I'm sure if PADI really wanted to, they could program Nitrox related stuff into their eRDPML device.

But regarding your original question, I think the dive shops are just being realistic -- these days it's probably unusual to not have a computer.

 

[The Light Eternal]

During my last checkout dive everyone but me had the eRDP-ML (I had the plain tables) and I calculated my pressure groups way faster. Just sayin'

 

[ajduplessis]

I understand that DC make life a lot easier, however students need to understand what and why they are doing things. Saying that it reduces the amount of time due to learning tables are absurd. You only need one table and don't need to learn/remember it, you read them.

Plan your dive, understand the MOD, select/blend your Nitrox, and determine EAD and dive of air tables. Simple and straight forward.

 

[mk706]

Wholly agree that one must understand tables to understand the model. Tough not to use dive planning software. There are just some many apps out there, especially on handheld devices. I find myself frequently planning dives and best mixes on my iPhone (for practice and curiosity). Am glad I own the tables and know how to use them. Have not planned an actual dive on tables outside of a training environment.

 

[DevonDiver]

It does what it says on the tin. If you are one of the majority of divers who uses a dive computer to plan and track your dives, then the computer-only nitrox course allows you safe access to using nitrox in a convenient, cheap and quick (1/2 day?) course.

In contrast, if you still feel a need to use PADI tables to plan and track your dives, then you'll have to search for an instructor that offers a tables-based nitrox course. All you really need to know is how to calculate an EAD... hardly rocket science.

The nitrox course isn't at a technical level, neither should it be viewed as an academic venture into decompression theory, model function or discussion on algorythmic consequences.

Divers who have an interest in the academics of decompression would find it far more worthwhile to conduct a little self-study with Mark Powell's 'Deco for Divers', rather than trying to turn a recreational nitrox course into something it is not.

 

[tstormdiver]

When I teach OW, I still teach tables & I also teach the computers. By teaching tables, I am teaching my students HOW & WHY their computers read what they read. Decompression needs (when on air) are based primarily on 2 things- time & depth, regardless of the algorithm used. When I teach Nitrox, I also throw into the mix how the gas mixture affects the time & depth (MOD). I still go over tables when teaching Nitrox because there are several instructors at our shop & not all the students are taught tables (SSI has made teaching tables an option, not mandatory) in their OW course. There have been times that the Nitrox course I teach is their first exposure to using tables. Even with the exclusive use of computers in OW class, the students need to know how & why their computer is figuring their NDL's the way it does. The tables do that (in a much simpler form).

 

[The Chairman]

You guys are killing me! I can almost hear Doris Day singing "Gonna Take a Sentimental Journey"! Tables have their place, but PDCs have all but replaced them for recreational diving.

Here are some facts:

• Understanding Deco theory is not dependent on learning tables.
• PDCs (Personal Dive Computers) are not derived from tables. Both are derived from algorithms.
• Instructors should be teaching students to use the equipment they will be diving with. For most divers this is a PDC and not tables.
• PDCs don't get narced.
• PDCs provide an accurate record of your dives and safety stops.
• PDCs represent N2 buildup with an easy to understand (intuitive) bar graph rather than confusing "letter groups".
• PDCs don't forget when you submerged or when you surfaced.
• PDCs don't forget to reset the witness mark on your depth gauge.
• PDCs sound an alarm when you exceed your NDL, MOD or ascent rate.
• Learning PDCs can be less intimidating to a novice diver.

I don't teach tables to my OW students unless they specifically ask me to. No one has asked so far.