computer dependent divers...

[underwater daphne]

Your other gear is all passive technology. Your computer is not. If you don't understand the difference, or why this makes an equivalent dependence unwise, find an engineer to sit down and explain it to you.



THAT is a scary statement. If you have that little confidence in your own ability to perform basic diving tasks, aren't you worried about diving?
One, there is really not any real math in using the tables. If you can have a credit card without getting into bankruptcy, then you can use the tables; it's almost exactly the same process. There are 12 year olds learning to use the tables every day. If you have trouble with it, you shouldn't just accept that, you should find a way to overcome it.



What if your buddy has the same type of computer - for that matter, many of the computers available today share the same internal hardware. Oh, they couldn't all fail at once, and in a way no one noticed, could they? Are you old enough for the words "Pentium Bug" to resonate with you? How many thousands were in the hands of consumers before that one was noticed? How many more before Intel actually admitted that it was true? Anyone here ever dealt with Intel's QA processes? They're the benchmark. Check out the "copy exact" policy to see what fanatics they are, and yet, this one slipped by them.

Your computer could fail in ways you would NEVER detect, unless you understood the principles it operates on well enough not to say "i don't know what would be more reliable in the long run - my comp or my table skills."

Computers are not inherently bad in diving, but your statement is a screaming advertisement for the reasons people object to computers.

wow, you make it seem like i'm stupid!!

no, i will not ask an engineer how my comp works. i don't care, it just works. i'm not a programmer or a hacker or a computer fixer whatever.

just cause i don't see the point in using tables or trusting tables over my computer, doesn't mean i don't know how. it's just a hassle getting into it again, when i don't need it. i seriously think my computer is more reliable and an important part of my gear. it's there for that purpose only, me?, i often have other things on my mind to distract me and interrupt my calculations.

adding to that as far as i've read all agencies use diferent tables which also calculate differently. i might be mistaken! but how do you know which of these agencies provide the most accurate table?

and i'd be very happy if my buddy had the exact same computer, means he has a good one and one i know how to read without effort.

 

[DORSETBOY]

1) So what. Tables don't allow for saw tooth profiles. For that matter, is there a large training agency that condones reverse profiles? The whole point of a computer, in some cases, is that these dives can be done safely and extend dive time. Whether you like these dive profiles personally or not, can you offer any factual evidence that they are "wrong"?

3) OK. But what does this have to do with computers? Do divers without computers inherently pay more attention to their position in the water column? Does a reliance on computers infer a greater risk of DCS? Do bouyancy skills fade with a loss of table usage skills?

My experience of seeing divers doing saw tooth profiles is that the majority are people relying on their computers to 'let them' do this. In shallow water in particular, the fluctuating ambient pressure on a saw tooth profile increases dcs risk as I'm led to believe it encourages 'bubble' formation, computers don't take this increased risk into account. I'm not saying every diver using a computer dives saw toothed profiels but rather that the vast majority of divers performing saw toothed profiles are divers who think they can get away with it cos they use a computer.

Buoyancy skills don't fade with a loss of table usage but if oyu dont understand the theory behind how computers work and dont plan your dive then you are unlikely to know if the readings on your computer are erronous.

Factual evidence for saw toothed profiles being wrong? yes, I've seen a dive leader getting badly bent beacuse of this.

 

[underwater daphne]

not that i agree or disagree, but he might have gotten bent for another reason. you can't SEE someone getting bent.

and that has nothing to do with a computer. maybe you think it's the majority, because the majority has some kind of dive computer.

 

[RonDawg]

not that i agree or disagree, but he might have gotten bent for another reason. you can't SEE someone getting bent.

While you may not be able to see the bubbles actually forming in the blood, you can see the symptoms, as another member recently posted:

http://www.scubaboard.com/t68519-.html

 

[ndl]

While you may not be able to see the bubbles actually forming in the blood, you can see the symptoms, as another member recently posted:

http://www.scubaboard.com/t68519-.html

micro bubbles forming from saw toothed dive prifiles are accounted for in most dive computers. that's why they monitor 9 differant tissue gruops ( slow tissue and fast tissue) . computers also take this into account in the following repeditive dive profile. This fact alone makes diving a computer safer than diving tables.

The major risk of dcs comes 5 min. after the diver reaches the surface. that's when the release of presure allows N2 to become gas bubbles.

It's a will documented fact that from the safety stop to the surface the diver should take 1 min or more. this will off gas the most N2

 

[String]

Some reasons for computer vs tables is firstly tables are inherently more conservative as they arent tailored for the exact dive profile - they assume a square profile dive with all the time spent at the maximum depth in general. Computers calculate on the fly and you see a lot of people skirting the NDLs by 1 minute by altering depth (why!? deco wont kill you!). This tends to result in saw tooth profile and puts the user near the statistical edge of the curve.

Tables are at the end of the day a load of statistics, staying within them you are *unlikely* to get bent assuming a normal sample. The nearer you stray to the edges of this curve the higher you statistical chance of getting a hit.

Computers simply allow unthinking users to get nearer to the edge and consequently could see more people suffering as a result.

 

[O2BBubbleFree]

Computers simply allow unthinking users to get nearer to the edge and consequently could see more people suffering as a result.

IMO stupid people do stupid things. Computers don't bend people, people do.

 

[String]

Exactly.

 

[BigJetDriver]

OKAY, TIME FOR STANDARD DISCLAIMER:

To whit, (1) a diver must understand the table he is using, and, in a general way, the design of the algorithm it is based on. (2) All mechanical and/or electro-mechanical devices can fail, so it behooves one to have redundancy, and a back-up plan. Here, aviation is an excellent planning model. (In diving, of course, that would mean depth gauge, timing device, and back-up tables.)

NOW:

Having said that, I will again point out that absolutely NO human being of whom we are aware today can sample factors associated with time versus gas fractions versus position in the water column, and insert these into a mathematical model, and re-compute the equations AS FAST, AS OFTEN, or AS RELIABLY as a micro-processor. (Should there be such a one, Professor Xavier needs to know his or her name right now!)

THUS:

We choose an algorithm, insert that model into our desk-top, plan our dive, and check our results against the tables.

(---Always, we must remember GIGO THE TERRIBLE [aka Mr. Murphy]. He can and will mess things up whether we head-compute or machine-compute!---)

We then insert the parameters into our wet-computer, and go diving. The capabilities of our computer give us the most accurate fine-control over the timing and stops in our dive that is possible.

IN SUMMATION:

All but the most recalcitrant would agree that, for technical diving and mixed-gas use, the dual-phase models are superior. Thus, one would have to choose a wet-computer having that capability.

Combine that with the requisite flexibility and wide control of parameters needed, and one finds the choices narrow very dramatically.

AFAIK, the VR-3 and the H-S Explorer are the only two with the maximum number of gas choices, included deep-stop construction, extended parameter control, and dual-phase models. The H-S is the only one in its class with full RGBM.

As both a pilot of the B-777, and an Instructor Trainer for IANTD, I find that combining the thinking and training of both worlds seems to net the best results.

POST-SCRIPTUS,

I would definitely agree with and echo a recent statement by Neptuno: "(The) computer is a good back up, (but) don't let the computer take over your brain."

Please take a moment, however, to re-read my "Standard Disclaimer".

The "Amish Diving Society" always says: "Computers Rot Your Brain." They are, of course, ABSOLUTELY wrong. Computers do not rot your brain. LACK OF USE ROTS THE BRAIN.

The computer is an electro-mechanical device, nothing more. If you are a Luddite, however, you fear "THE MACHINE" and imbue it with sentience. Worse, you believe with all your being that it posesses "EVIL" in great measure. If one simply touches such a powerful icon of evil, one will become corrupt instantly!

Because of this strange and twisted belief, they engage in weird shamanic rituals designed to "cripple" the evil thing, lest it infect them.

To refer again to my first post above, in essence I am saying:

(1) Use brain first.

(2) Use computer as tool.

(3) Be sure to continue to use brain.

(4) Repeat as necessary!

As Mr. Natural always said: "Get the right tool for the job, kids!"

:doctor:

 

[ndl]

IMO stupid people do stupid things. Computers don't bend people, people do.

The best advice to come down the pipe in a long time is the use of the DEEP STOP. A deep stop can be done with or without a computer. by taking 2 min. at half the deepest depth of a dive the diver does two things. 1 they releave half of the total presure to let the off gasing begin and 2 they change the average depth of the dive.By doing a deep stop the safety factor is increased by a large margin.