technology

[M&P+4]

I pulled this out of another thread mostly because I thought it would be fun to have a healthy debate!




Quote:
Originally Posted by M&P+4 http://www.midwestdive.com/images/buttons/viewpost.gif (http://www.midwestdive.com/forums/showthread.php?p=16290#post16290)
I never took you for a technophobe Bob - but the dRDP does look pretty cheesy (coming from a Wisconsonite that's saying something!).
I most certainly am not opposed to teaching the dive tables but emphasizing it does seem an awful lot like using an abacus to do your taxes when you have TurboTax loaded on the PC sitting right next to you. Fun for some maybe, but it does seem a bit cave man to me.

Okay, then let me know how your taxes come out when you lose power due to a spring storm on April 12th, and power is out for 5 days. What I mean by that is, if you are dependant on the eRDP, and you bring it on the boat, and it dies, you are clueless about tables. Granted, the dive computer is the way to go, buy this is your life we are talking about. I think, in my opinion, its very important to understand what the numbers are telling you.

[M&P+4]

Okay, then let me know how your taxes come out when you lose power due to a spring storm on April 12th, and power is out for 5 days. What I mean by that is, if you are dependant on the eRDP, and you bring it on the boat, and it dies, you are clueless about tables. Granted, the dive computer is the way to go, buy this is your life we are talking about. I think, in my opinion, its very important to understand what the numbers are telling you.[/quote]

If it doesn't work you don't dive - similar to many other things we do each day that we don't understand.

We all use technology everyday that we trust our lives to without understanding the basics - anti-lock brakes and air bags would be a good example.....are we having fun yet??? :D

[DeepDiverBob]

I pulled this out of another thread mostly because I thought it would be fun to have a healthy debate!




Quote:
Originally Posted by M&P+4 http://www.midwestdive.com/images/buttons/viewpost.gif (http://www.midwestdive.com/forums/showthread.php?p=16290#post16290)
I never took you for a technophobe Bob - but the dRDP does look pretty cheesy (coming from a Wisconsonite that's saying something!).
I most certainly am not opposed to teaching the dive tables but emphasizing it does seem an awful lot like using an abacus to do your taxes when you have TurboTax loaded on the PC sitting right next to you. Fun for some maybe, but it does seem a bit cave man to me.

Okay, then let me know how your taxes come out when you lose power due to a spring storm on April 12th, and power is out for 5 days. What I mean by that is, if you are dependant on the eRDP, and you bring it on the boat, and it dies, you are clueless about tables. Granted, the dive computer is the way to go, buy this is your life we are talking about. I think, in my opinion, its very important to understand what the numbers are telling you.

I thought about doing this myself, just had a few other things going on.

[do it easy]

I didn't read the thread where this discussion popped up from, but I'll throw down and stir up the pot a bit :D

As far as tables go, I think that they are important for dive planning purposes. Students should realize that doing two back-to-back 100' dives with just enough time between dives to change out tanks is a bad idea.

I'm not saying that they have to memorize the tables, but they should have an understanding of the information there and how it will affect their dives. Once they meet that requirement, using the tables should be easy.

I rarely dive with my computer nowadays- I'm usually diving shallow enough that it doesn't matter or deep enough that I'm on tables. However, in situations like the meet up at Mermet, I will dive with the computer to gain the benefit of multilevel diving, although I try to keep an idea of what I think my limits are throughout the dive.

I would draw the analogy that diving without understanding tables is like learning to drive in a parking lot. You might be fine at 15 mph and parking in little spaces, but once you get out on the highway, it's a different set of rules.

I don't put too much weight on "the tables saved my vacation when my computer died" reasoning. It's only money and no one is forced to dive. I do put a lot of weight on divers understanding how their profiles and surface intervals affect their health and general well being. If that involves a little math and head scratching, then so be it.

[scububa]

I gotta post this because I thought it was pretty funny... as I was reading the first part of this thread, I lost power due to a storm.

I think it is ironic that when you consider all the changes and overall improvements in diving, that divers tend to be pretty resistant to change. That is an observation that has stayed constant in the five years I have been paying attention to dive chatter.

Having said that, I fully agree that table training seems necessary to underscore the concepts of real world time to gas absorbtion at pressure. I have this vision of someone gearing up for a repetitive dive, jumping in, and finally seeing that they only have two minutes NDL. But, I started diving with tables and then went to a computer.

Maybe this would be an OW - AOW difference. Dive tables as OW and then dive your computer after AOW???? But, in the long run if someone is going to enjoy OW resort dives and always be chaperoned, they probably don't need it. And, if a person is going to train and dive at more involved levels, they are going to get all the gas/reality instruction anyway.

[theskull]

do it easy said it well. The eRDP is a simple way to get NDL answers, but it does nothing to show the relationship the numbers have to each other, or how much you affect the outcome by slipping an extra 15 ft. deeper during the dive or staying 3 minutes longer than you planned.

I am all for divers using a dive computer while diving, and as soon as possible -- but would like for them to understand what the computer is using as a basis for what is being displayed and how much benefit they can get from longer surface intervals between dives.

theskull

[M&P+4]

I believe that physiology is more important to understand than being familiar with tables. Tables are a tool that are quickly losing value in the recreational realm of diving. Computers offer much more bottom time and remove potential life threatening mistakes while working thru the tables.

I say an introduction to the tables is ok but stess physiology and the benefits that technology offer.

[do it easy]

What part of physiology would you stress? The part about what happens when tissues become oversaturated with nitrogen? The part about what nitrogen bubbles do when the get into the arterial side of the plumbing? The part about how the body rids itself of nitrogen over time?

I'm not convinced that you can separate the physiology from the tables and still have the physiology be meaningful.

[M&P+4]

Time, depth and surface interval affect all aspects of physiology. I don't think someone needs to be fluent with tables to understand the affects of nitrogen on the body. I'm a fan of using a bottle of soda to illustrate a gas in solution and how different variables affect how it comes out of saturation. Anyone can understand how a can of pop will behave if shaken then opened suddenly -

[MgicTwnger]

do it easy said it well. The eRDP is a simple way to get NDL answers, but it does nothing to show the relationship the numbers have to each other, or how much you affect the outcome by slipping an extra 15 ft. deeper during the dive or staying 3 minutes longer than you planned.

I am all for divers using a dive computer while diving, and as soon as possible -- but would like for them to understand what the computer is using as a basis for what is being displayed and how much benefit they can get from longer surface intervals between dives.

theskull
Once again, Bill hits the nail on the head!

[juls64]

You can already dive without learning tables. It is called a resort course or you can achieve the Scuba Diver rating of certification (PADI). You do not learn tables and you can scuba dive. You are limited in depth and are required to dive with an Instructor or divemaster.

[DeepDiverBob]

You can already dive without learning tables. It is called a resort course

I'm sure there are people that have had a good experience with these, but I know too many people that refuse to give scuba "another try" because the resort course ruined the experience for them. I have never taken the resort course, so I cant give a first hand experience.

[scububa]

Time, depth and surface interval affect all aspects of physiology. I don't think someone needs to be fluent with tables to understand the affects of nitrogen on the body. I'm a fan of using a bottle of soda to illustrate a gas in solution and how different variables affect how it comes out of saturation. Anyone can understand how a can of pop will behave if shaken then opened suddenly -

There are several levels of "understanding something". I think that understanding of the physiology of gas combined with the abstract representation in the tables helps bring home the point of depth and time parameters pretty effectively. It puts it into distinct, diver controllable variables. Any table or chart is still an abstraction (of real life), but normally more easily grasp by folks that an even higher abstraction of a concept and a formula. I think the balloon model abstraction is also very good for the same reason. It is generally much easier for people to bridge the ballon to their lungs than the inverse proportion formula P1V1 = P2V2.

[M&P+4]

There are several levels of "understanding something". I think that understanding of the physiology of gas combined with the abstract representation in the tables helps bring home the point of depth and time parameters pretty effectively. It puts it into distinct, diver controllable variables. Any table or chart is still an abstraction (of real life), but normally more easily grasp by folks that an even higher abstraction of a concept and a formula. I think the balloon model abstraction is also very good for the same reason. It is generally much easier for people to bridge the ballon to their lungs than the inverse proportion formula P1V1 = P2V2.

Well stated - I agree whole heartedly.

So where does this leave us - should we gobble up the technology that is offered and let the tables fade into the history books? or should their use still be stressed as the primary source for dive profile management?

Still having fun? :D

[DeepDiverBob]

Well stated - I agree whole heartedly.

So where does this leave us - should we gobble up the technology that is offered and let the tables fade into the history books? or should their use still be stressed as the primary source for dive profile management?

Still having fun? :D

Taking a break from work, so yeah, I'm having fun now...

I think the tables should still be taught, and the computer should be used as well. I see too many people become too dependent on their computer, and dont know what the numbers represent. In my opinion, that is a bad thing. I think TomToms are pretty neat things too, but kids should learn to read a basic map, atlas or even better, street sign.

[CaptnDale]

A dive table is just a tool. As an engineer, I have used a multitude of tables, graphs and charts. They are useful, but not ends in themselves. When I was in school we used slide rules. While slide rules are useful and their use can also teach some of the basic mechanics of mathematics, I would not argue that we should still be teaching the use of slide rules in preferance to calculators and PC's. Likewise, teaching the theory of decompression does not depend on the particular tool used.

[theskull]

A dive table is just a tool. As an engineer, I have used a multitude of tables, graphs and charts. They are useful, but not ends in themselves. When I was in school we used slide rules. While slide rules are useful and their use can also teach some of the basic mechanics of mathematics, I would not argue that we should still be teaching the use of slide rules in preferance to calculators and PC's. Likewise, teaching the theory of decompression does not depend on the particular tool used.

I'm in complete agreement with this. But I don't personally think the eRDP is an effective teaching tool. Something better will come along, and then I'll be ready to put the tables away.

A couple examples, from the handful of classes I've helped teach using the eRDP.
1. The students who are taught the eRDP with no mention of tables obviously know no differently and are happy, but you can tell that the answers are just numbers to them.
2. The students who are taught the eRDP and then shown the tables as an afterward generally express a better understanding of the concepts involved, and many of them demand to buy a copy of the tables. Exception: the really young ones, teens, who love the eRDP and are trying to figure out how to text each other with it!
3. Even though I have taught a couple dozen people to use the eRDP, if you throw one in my lap and ask me to do a repetitive dive sequence, I have to puzzle my way through it. But toss me a table and I'll have the answer in seconds even though I haven't actively used my tables in years. Point is, once the table is understood it is intuitive; but once the eRDP is understood it is still a little quirky.

I'm sure a better electronic solution will be along soon, though.

theskull

[M&P+4]

This is the first time I've even heard of the eRDP. It really doesn't sound like it has any improvements over the tables. What are the benefits of it? I'm all for new tools but if they don't offer more than the old one, why bother?

[Atlaua]

I think we need to separate the divers.

The weekend warriors who go destroy a reef once every year or so don't need to bother. They just need to follow the DM and stay resonably safe.

The divers, people who enjoy diving for diving, need to have some basic background on what is going on.

The gluttons, need to know it all...

[CaptnDale]

This is the first time I've even heard of the eRDP. It really doesn't sound like it has any improvements over the tables. What are the benefits of it? I'm all for new tools but if they don't offer more than the old one, why bother?

I, personally, do not think that the erdp is a very useful device. It is not waterproof, so it is doubtful that it will last very long in real-world conditions. The functions of the device are performed by most good dive computers in the "planning" mode. The only real advantage of the erdp is that it gives consistent, measurable results in an educational setting. Of course, that is what PADI is going for - an electronic device that is inexpensive enough to be sold to entry-level students, gives the same results as the PADI tables and will yield consistent, testable, results if used correctly. But an instructor could equip all his students with one model of dive computer and achieve the same results if he were willing to accept answers that were not in step with the tables for testing. I remember that when electronic dive computers were first introduced many divers, especially instructors, did not trust them because they did not give the same answers as the Navy Tables. Navy Tables were sacrosanct and anything that did not follow them perfectly could not possibly be safe.

[ppo2_diver]

I completely agree that people need to learn HOW the tables are what they are and shouldn't follow computers blindly. If they look at them in more detail, they will see that it is simply an algorithm and can extrapolate NDL times without having to look at the tables. I haven't used a computer in 3 years and haven't used tables (for recreational diving) in 2 years. I know the patterns in the tables and run my dives with that. I also know how Nitrox affects my NDL times I calculate. Again, knowing the patterns and the hows/whys allows me to do this. For tech dives, I still cut tables but next year I will start doing more tech dives using ratio deco and see how my calculations compare to the tables.

[reefraff]

Here are two truths:

Only in the rarest of circumstances does anyone use the tables outside of class. Rhetorically, how often do you see anyone on the back end of a dive boat or at the quarry working their tables? Shoulda, coulda, woulda aside, the real world is that most divers don't use the tables which means that they have little value beyond teaching the concepts of nitrogen loading and the time/depth correlation and impact of repetitive diving.
Recreational divers should all be using dive computers to monitor their dives and coach them out of the water. Most of them simply will not plan their dives but an electronic nanny will help keep them safe and should be a standard piece of gear. The question isn't whether or not they should trust a computer to watch over them, it's whether or not it's better to trust a computer than Manny the DM - or blind luck.


Good instructors adapt to their students needs and abilities and don't let antediluvian sentiment or pious zealotry get in the way of being effective. Things change and the eRDP is a new tool that makes learning about decompression issues easier for some students, harder for others. Most students under the age of 30 don't need to be taught how to use the eRDP. They have an intuitive grasp of the technology and all they need to learn/be taught are the concepts of time/depth and residual nitrogen. Conversely, tables are foreign technology to them and the struggle to learn how they work gets in the way of learning about fizziology.

I've also found that students who learn on the eRDP are halfway home to the decision to buy a computer. The eRDP is comfortable for them and demonstrates the value of having a computer far better than the manual tables can.

The older the student, the less valuable the eRDP can be and, at some point, it's often better to teach them what they need to know on the tables. Just remember, they don't need to know how to work the tables, only the basic concepts and how to answer the three NDL questions: how long can I stay down, how deep can I go and how long do I have to stay out of the water? Whatever tool is going to get that done most effectively is the tool to use.

Never mind custom tables and ratio deco - those are the province of technical divers and trusting recreational divers to learn or use them effectively is irresponsible. For that matter, it's been my experience that many technical divers who attempt ratio deco (aka deco on the fly) end up the worse for it.