Info Why are tables not taught in OW classes anymore?

[Eric Sedletzky]

What John is trying to politely point out is that your question is like "have you stopped beating your wife yet?" -- both "yes" and "no" are the wrong answer.

Well not really.
My question was a curiosity.
Believe it or not I have run into people that think teaching long hand basic arithmetic is a waste of time because they claim nobody does math that way anymore. Nobody sits down with a pencil and paper to figure it out, they will pull out a calculator or just hit the calc app on their phones. Yes, children are being given smart phones, it’s the future. If they learn basic mental math like adding 54 + 34 in their heads at some point then great, but not mandatory. This is real.

How does this relate to tables vs computers? It doesn’t really because computers can do way more in the diving world than tables could ever do, so computers are a tool that greatly extends the parameters in diving.
My point is that computers are taking over a huge part of our lives in almost every way we live now to supposedly make life easier, but IMO it’s also breeding an entire generation of non-thinking people because they don’t have to.
We need to be careful what we wish for.
BTW, AI is getting flat scary!

 

[John C. Ratliff]

Seems like alot of complicated answers that don’t really answer the question. Here goes. 1. Tables are complicated and every organizations tables are a little different. NAUI diver goes to resort with PADI trained dive master. Tables = problem. Computer = no problem. 2. Computers have gotten much simpler. 3. Computers have gotten much cheaper. $200 or less many times. 4. Computers have beepers or alarms and you can take them with you tables don’t. 5. Iphone generation understands computers. 6. And finally and most importantly, computers are safer, they don’t make mistakes, and they’re more accurate. Why use a slide rule when you have a scientific calculator. Why step off a distance when you have a laser range finder. Theory should be taught but tables kill.

Well, today math students don’t understand some basics that make calculations without a calculator easy. For instance,

342,000 x 250,000 can also be written:
(3.42 x 10^5) x (2.5 x 10^5) equals 3.42 x 2.5 x 10^10
It takes no time to get a pen and do the multiplication, to get
8.55 x 10^10 equals 85,500,000,000

The thing is, when someone (adult or kid) does this calculation on a calculator, they don’t understand the basics of multiplication and the ability to break the number down and multiply the number, and add the digits. By using the calculator, we gain a lot in speed and accuracy, but loose a lot in understanding. Why do you think most school kids today are so scared of math?

The same principle applies to learning the tables.

One other aspect; you state that “Computers have gotten cheaper. $200 or less many times.” Well, yes that is true, but $200 prices out a lot of people from diving. Diving and today’s divers have become gear-dependent, rather than building upon their skills and understanding. A set of tables is probably about $15, while a waterproof watch is now under $100, and a depth gauge can be bought for about the same price (or made if you want to try making a capillary gauge).

SeaRat

 

[John C. Ratliff]

Tables don’t kill but it got some attention. But, tables aren’t algorithms, they’re approximate guesses. Computers use the algorithm as intended. Mostly, people just don’t use them and never did. Why teach something no one will use when there is a far better system anyway. Schools don’t teach typewriters anymore but they still make them. For those that don’t know, the is a machine better than typewriters. It’s coincidentally called a computer,

Can you tell me why, on a computer, you’re still using the QWERTY keyboard? The Dvorak is much, much better (I’m using it right now). If you want to really screw up someone, change their keyboard to Dvorak and see what happens; it’s kinda fun. I had a tech guy come in years ago to update the software on my computer, and he started typing. It was gibberish. He tried again, and again it was gibberish. He finally turned to me and asked what was going on, and I converted my keyboard back to QWERTY. I decided to switch to the Dvorak keyboard (which is on every computer system now made) because I was coming down with carpel tunnel syndrome from rototilling on my land. And I never looked back.

SeaRat

 

[scubadada]

Hi @John C. Ratliff

Do you speak Esperanto?

 

[dmaziuk]

...
How does this relate to tables vs computers? It doesn’t really because computers can do way more in the diving world than tables could ever do, so computers are a tool that greatly extends the parameters in diving.

It doesn't because neither the computer nor the tables teach the "basic arithmetics" of a decompression algorithm.

 

[John C. Ratliff]

Hi @John C. Ratliff

Do you speak Esperanto?

Unfortunately, I do not speak Esperanto, but I do have Google Translate, so feel free to ocmmunicate in Esperanto.

John

 

[steinbil]

It doesn't because neither the computer nor the tables teach the "basic arithmetics" of a decompression algorithm.

Agreed. What tables teach is:
- Plan your dive, dive your plan
- Respecting the limits of your plan (and training)
- Being conservative

This can be taught in many ways, and I hope it is all stressed in OW training with any agency. However, because the tables are a little bit more clunky, they require more planning and slows you down a little bit. The simple act of taking more time, thinking more about your plan and the limits, is helpful. In the same way taking handwritten notes is helpful, because it forces you to slow down and think.

 

[boulderjohn]

The thing is, when someone (adult or kid) does this calculation on a calculator, they don’t understand the basics of multiplication and the ability to break the number down and multiply the number, and add the digits. By using the calculator, we gain a lot in speed and accuracy, but loose a lot in understanding. Why do you think most school kids today are so scared of math?

The same principle applies to learning the tables.

Math is still taught in schools.

There is nothing in understanding how to use the different columns in a table that helps you to understand decompression theory. They are two different things. People confuse that because tables and decompression theory are often taught together. Mark Powell wrote an entire book on decompression theory--Deco for Divers. If you read it, you will understand decompression theory better than 95% of the world's divers, but you won't know a thing about how to use a table.

 

[Belzelbub]

Can you tell me why, on a computer, you’re still using the QWERTY keyboard? The Dvorak is much, much better (I’m using it right now). If you want to really screw up someone, change their keyboard to Dvorak and see what happens; it’s kinda fun. I had a tech guy come in years ago to update the software on my computer, and he started typing. It was gibberish. He tried again, and again it was gibberish. He finally turned to me and asked what was going on, and I converted my keyboard back to QWERTY.

I switched to Dvorak many years ago. I did it mainly to break myself of the habit of looking at the keyboard. Learning the layout with an image of the Dvorak keyboard was a painful week or two. Since then, though my typing speed has improved. Watching the techs at work try to fix something is usually fun.

I learned using tables. I still have some, but for the most part they aren’t needed anymore. Today, it’s really not necessary to teach tables. Teaching the theory is important, but this can be done with computers at least as easily. Perhaps easier depending on the computer. My computers show tissue compartment graphs, so it’s easy to see how different tissue systems on and offgas at different rates.

Even if the computer doesn’t have those graphs, seeing the change in real time during a dive can help with understanding how pressure affects time. On a checkout, the instructor could take the students down to 60’, and have them note the NDL, then ascend to 30’ or so and see what the NDL is now.

Whether teaching tables or computers, the most important thing is that the diver is taught, or at least understands, the gear they are using. Going from tables to a computer is a logical progression. Going the other way is not, and with the cost of some computers today, probably not necessary. Yes, a basic dive capable timer is cheaper than a computer, but when you add in the cost of a depth gauge, the cost is a lot closer.

 

[John C. Ratliff]

Benzelbub and others,

I agree with what you are saying, but you've got to see that a glance at Table 1 will show clearly the relationship between time for the NDL and depth. It is a very visual form of learning that the nitrogen is absorbed much faster at depth than at the surface. It also shows clearly the "knife edge" of the NDLs.

Saying that, I'm not against computers. I'm simply showing how gear-dependent today's divers are compared to divers when I started diving. This also means that scuba diving has become a "rich person's sport," rather than a sport for everyone.

SeaRat