The problem with computers is not that they aren't tables. The problem with them is that people don't learn how to use them. It is somewhat difficult to teach a computer-based class if everyone has a different computer, or if no one owns a computer and you are teaching them how to use the shop's devices, which are ancient and don't include dive planning functions. This process easily leads to the "magic bracelet" phenomenon. But if you really TEACH nitrogen absorption and elimination, and what decompression is, you can give students the background to use their tool more rationally -- just as better teaching of those matters helped students understand the tables better, too.
I submit, that you need to teach those concepts regardless of whether you are teaching tables or teaching computers. Decompression theory does not change because the tool you use to calculate the NDL does.
There is also a lot more to dive planning -- and I'm sure you know this -- than just calculating some rough idea of the NDL. Navigation, gas, objectives, conditions, current ease of entry/exit, bottom topography.... you name it. There can be several limiting/controlling factors to how one might want to dive a particular site. The NDL at max-depth is only one of those factors... and if you calculate that NDL using a table, or you calculate it by looking it up on your computer... the number is still the number.
As for computers without planning functionality.... can you give me an example of one that has been manufactured since about... say 2005? I can't image a student wanting to buy a used computer much older than that and I'm not aware of any modern computers without a planning mode. If there is one out there, I'd like to hear it.
R..
---------- Post added March 20th, 2014 at 01:24 AM ----------
Forgetting something is perfectly fine. We are not machines, and we do forget.
Well at least we got that far....
However, failing to realize that your skills have slipped and you need to refresh your memory IS a problem. If someone's skills slip, and they do not put forth the effort to correct this, they are to blame.
I know you really, really, really want to shift the blame around, but you can't. Someone who forgets a skill and doesn't attempt to rectify that is to blame.
It's called personal responsibility. Do they have that where you are?
Ok, I see what you mean now. I still don't understand why you need to be kicking at my shins every time you make a post though. You could try to communicate your point with a more neutral tone. You *do* realise, I hope, that something doesn't become more true the louder or more aggressively you say it.
As for "blame". I don't know if it's the word I would choose for it. "blame" has an accusatory tone, a sort of combative denunciation of the person. What I think you mean is that the diver in question isn't taking responsibility for some aspect of their safety.
I could agree with that if the diver used tables for planning (or intended to) but couldn't remember how they worked and couldn't be bothered to brush up. However, if the diver in question is using a computer to plan the NDL and does this adequately, then I don't see a pressing need to for them to keep the table theory fresh in their minds. I could become relevant if, for some reason, they decided to use tables, but as long as they are aware of their deficit in practice and take the time to go through it in a timely manner then I don't see the problem.
This really comes down to the core of something you've been arguing since early on in this thread, which is that (if I understand you) you believe that people should know the tables and be ready to use them at any moment
just in case they might want to.
There is another way of looking at this, which is that you don't have to have all your knowledge constantly prepared as long as you know where to look it up (ie
just in time). I read (as most people do) in excess of 200 books when I went to university and I have forgotten much of what I read in the intervening time because I don't use that knowledge every day. But I am aware of the theory to varying levels of detail and I'm aware of where I can look it up if I need it. Insofar that it's necessary for a modern diver to learn tables at all, I've been trying to argue that the same thing is true here. I haven't been trying to "shift blame" (your words) because I don't think there is anyone to blame if the diver forgets how the tables work over time. There is, of course, a major problem if the diver decides to
use them and fails to brush up on it first (just in time).
I'm still not sure if we're talking about the same thing but missing each other's point or that we've settled on two different points of view (just in case / just in time) and simply don't agree with each other's starting principles.
R..
