How does the table math work?

[Blackwood]

I believe that while your first sentence may be true, the second does not follow logically from the first. It may be that neither teaching tables by NAUI/PADI works nor does relying on dive computers.

Agreed. I'm really starting to appreciate your posts/thought process.

If the agency doesn't establish a curriculum which adequately describes the fundamentals of recreational decompression, and/or
If the instructor can't be bothered to properly explain recreational decompression, and/or
If the student can't be bothered to properly learn recreational decompression,
Then the tool is irrelevant.

I don't imagine that an instructor who doesn't explain 'RNT' as applied to dive tables would suddenly start explaining 'RNT' if he switched to personal dive computers.

 

[tesnusxenos]

Wow.... I am surprised that this topic caused so much conversation. I understood how to use the tables, I just wanted a clarification on the math behind them. Most people are not interested in the math and can use them fine without knowing. The first person explained the answer to my question quite well. I really don't see how this indicates that teaching the tables does not work. Many people drive cars quite well without knowing how or why they work.

 

[rstofer]

Many people drive cars quite well without knowing how or why they work.

When I took driver's education back in the early 60's, we did have to know how a car worked. We were taught all of the intricate details of the engine, transmission, differential, brakes, steering and myriad other things. It wasn't on the DMV test but it was taught in school.

Richard

 

[rstofer]

I don't imagine that an instructor who doesn't explain 'RNT' as applied to dive tables would suddenly start explaining 'RNT' if he switched to personal dive computers.

There's no point in explaining RNT in the context of the PADI eRDP. It doesn't provide the number. It just gives the new ANDL. If the student wants to know the RNT, they have to subtract the ANDL from an NDL with no prior dives. It's my understanding that the test hasn't kept up. Apparently there is a question about RNT and no way to get the answer with the eRDP.

Richard

 

[nereas]

Agreed. I'm really starting to appreciate your posts/thought process.

If the agency doesn't establish a curriculum which adequately describes the fundamentals of recreational decompression, and/or
If the instructor can't be bothered to properly explain recreational decompression, and/or
If the student can't be bothered to properly learn recreational decompression,
Then the tool is irrelevant.

I don't imagine that an instructor who doesn't explain 'RNT' as applied to dive tables would suddenly start explaining 'RNT' if he switched to personal dive computers.

So you did not get the point, that teaching dive computers is easier, more complete, and less error prone than teaching dive tables? Particularly when new students do not understand that RNT is a measure of blood saturation of an inert-like gas (N2), measured in "minutes" for a given depth?

Or are you saying that you agree, that dive tables are inappropriate, for more reasons than one?

 

[nereas]

There's no point in explaining RNT in the context of the PADI eRDP. It doesn't provide the number. It just gives the new ANDL. If the student wants to know the RNT, they have to subtract the ANDL from an NDL with no prior dives. It's my understanding that the test hasn't kept up. Apparently there is a question about RNT and no way to get the answer with the eRDP.

Richard

Is this the same thing as their "wheel"?

Don't only PADI DMC's learn how to use this, while the rest of the world ignors it?

[And ignors it with no difficulty, I might also add.]

Does this mean all new PADI divers need to take this new plastic wheel with them everywhere they go?

 

[nereas]

I believe that while your first sentence may be true, the second does not follow logically from the first. It may be that neither teaching tables by NAUI/PADI works nor does relying on dive computers. There are other possibilities, including:

• Some people may not be ready or motivated to learn what they need to know to be safe divers regardless of who teaches them.
• There may be a better way to teach tables than NAUI/PADI use. For example, it may be that the curriculum is sufficient but their selection of instructors is poor or their business model pressures instructors to push people through the system as quickly as possible.
• There may be a better way to determine safe dive profiles than tables that makes a diver safer.

I personally think all of the above are true for some segment of the diving population. A small number of people just want their certification so they can have fun on their vacation. Giving them a computer doesn't make them any safer because they will either do whatever their DM tells them to do, ignoring the computer, or do whatever they want to do, ignoring the computer.

I have witnesses the certification mill at work, it is not pretty. There is good information in the OW process, but some instructors don't want to answer your questions, they just want to push you through the system because they make money of trips and equipment sales, the instruction is a loss leader to get you in the door.

And while I am not a computer hater, I believe my study of the models behind the computers and planning programs makes me a safer diver.

Not trying to pick a fight here, just pointing out that it isn't a simple Door Number One or Door Number Two. take me for instance. If I am not a safe diver with tables, I would not assume that strapping a computer on my arm will fix the issue...

Your logic is actually quite good.

It could be any of those things.

And whichever, it is an indictment of dive tables in the 21st Century, either for use by beginners or even by advanced techdivers. Since beginners don't seem to understand the instruction, and advanced techdivers are going to use deco software tools anyway.

 

[rstofer]

Is this their "wheel"?

Don't only PADI DMC's learn how to use this, while the rest of the world ignors it?

[And ignors it with no difficulty, I might also add.]

No, the eRDP is a lot like a traditional calculator PADI eRDP Electronic Recreational Dive Planner

The Multilevel version is nearly identical except for firmware and price: PADI eRDPML Multilevel Electronic Recreational Dive Planner

The Wheel is a whole different animal. I have a couple but I haven't really studied them Dive Planner - PADI Wheel But, yes, I believe they are required for the DM course.

As I see it, a planner is useful if you know, in advance, what your dive profile will look like. That doesn't really help me because I NEVER know what the profile will look like. The planners can also back calculate a dive and tell you how fast you need to get to a chamber (sort of).

I used to write the ANDLs for all depths on my slate and as I made my dive I would look at my dive timer, the ANDLs and my max depth (along with the SPG) to decide when the dive was over. It worked pretty well. I'm still here...

I still like that approach.

Richard

 

[nereas]

Wow.... I am surprised that this topic caused so much conversation. I understood how to use the tables, I just wanted a clarification on the math behind them. Most people are not interested in the math and can use them fine without knowing. The first person explained the answer to my question quite well. I really don't see how this indicates that teaching the tables does not work. Many people drive cars quite well without knowing how or why they work.

Yah, we always talk a lot. Especially when someone makes an interesting post, like yours.

BTW, I can also tear my jeep apart and fix it, and also my DPV, and my motorcycle, and not to mention also my scuba gear (although I do take the regs themselves to an authorized service center annually / but I do understand the principle of the piston regulator / I'm just too pressed for time to take a DEMA class from Scubapro on Mark 20 & S600 maintenance).

 

[nereas]

No, the eRDP is a lot like a traditional calculator PADI eRDP Electronic Recreational Dive Planner

The Multilevel version is nearly identical except for firmware and price: PADI eRDPML Multilevel Electronic Recreational Dive Planner

The Wheel is a whole different animal. I have a couple but I haven't really studied them Dive Planner - PADI Wheel But, yes, I believe they are required for the DM course.

As I see it, a planner is useful if you know, in advance, what your dive profile will look like. That doesn't really help me because I NEVER know what the profile will look like. The planners can also back calculate a dive and tell you how fast you need to get to a chamber (sort of).

I used to write the ANDLs for all depths on my slate and as I made my dive I would look at my dive timer, the ANDLs and my max depth (along with the SPG) to decide when the dive was over. It worked pretty well. I'm still here...

I still like that approach.

Richard

So it is a dive planning tool that does not go underwater?

Basically an inexpensive dive computer that you cannot get wet?