Is a computer actually necessary?

[jviehe]

Kendall Raine once bubbled...
Further to the question of where I got 50%, I rumaged around and found the DAN source I remembered. It was actually a 1998 report done under a grant from DAN Europe, but I trust you'll forgive the imprecision.

On page 1625 you'll find "Overall, the "deserved-to-undeserved" DCS ratio in a population of divers lies ~50%."

Here is the link for those who want to stomp around in the weeds: www.daneurope.org/eng/jap98.pdf.

Ok, read it, but it deals more with PFO, and only as a side mentions the 50% stat, with not substantiated facts. So, I'm going to ignore it. Obvisouly there are a lot of factors involved, and in fact in the latest DAN Accident report, most (805) DCS seems to be caused by ascending too fast, one thing which computers are great at keeping tabs on, but this is just my analysis.

 

[Uncle Pug]

String once bubbled...
Well the brain is far less accurate in following the models.

Who wants to follow models. The Brain (hilarious the way you used the definite article so I'll follow suit) is much more clever than a computer and has greater capacity for input... including "The Voice." (definite article intended)

Why do people drive cars when they can walk?

Why drive a car to the kitchen to get a snack... in fact why even walk to the kitchen when I can have a bag of snacks sitting right here at my desk?

Why do calculators sell so well when an adding machine would do the job?

Why use an Excel spreadsheet to calculate my score for putting the word "scuba" on a pink square? (answer below for the those who've been using computers)













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[String]

Kendall Raine once bubbled...
Let me suggest a test to gauge how much you depend on your computer to do your thinking and planning for you. Next time you're diving, bring both a timer/depth gauge and your computer. Half way through the dive, hand your computer off to your buddy and conduct the remaining part of the dive without the computer. For the test to mean anything, you'll need to be honest and plan the dive as per usual-as if you intended to keep the computer the whole time.

Quite simply in that id look at my analogue depth gauge (which i always carry as its on a console) to determine my maximum depth, id look at my watch (which i always wear and set prior to rolling in) to work out my current dive time and would fish the tables out of my pocket (which i always carry) to work out how long ive got to go and/or how much deco to do. It'll always be worse than my real profile as tables assume square profile and i think i can safely say only 5% of my dives work out square. Of course, all that assumes ive lost my buddy as typically we only dive once per week and all own Suunto computers with the same algorthym

 

[colorado_al]

The fact is, the dive computer algorithms are quite good. I've got hundres of dives on my UWATEC with no problems. I always pre plan my dive with aid of tables and always have them in my BC pocket. However, I've seldom looked at them under water.
What it really comes down to for me, is that I never leave my life in the hands of one piece of equipment. That's why I have a computer and the tables. That's why I have an octopus, or spare air. That's why I dive with a buddy. That's why my BCD has a way to manually inflate. The computer should not be used as a substitute for tables and, I believe, vice versa. Use the tools you have at hand to your advantage, and by all means dive conservatively, so you don't test the boundaries of your system, computerized or not.

 

[String]

Uncle Pug once bubbled...
Who wants to follow models. The Brain (hilarious the way you used the definite article so I'll follow suit) is much more clever than a computer and has greater capacity for input... including "The Voice." (definite article intended)

However the human brain is far from capable of performing the required calculations and sample rate that even a simple computer can. If you can show me a diver who can update his mental dive picture at 0.1 second intervals with accuracies to 3 decimal places throughout the entire dive i might believe you. Otherwise i dont.

Why drive a car to the kitchen to get a snack... in fact why even walk to the kitchen when I can have a bag of snacks sitting right here at my desk?

If you have $30 change in a shop and the assistant only gives $20 because they "roughly guessed the amount" [brain] would you be happy? If they'd used the cashier till [computer] they could give you the exact amount.
Again, the brain lacks the precision of a computer device. The whole point of computers being invented in the first place was number crunching that would take a human hours.


People here are assuming incorrectly that tables are far safer and more accurate to follow than the algorythms in a computer. That isnt the case.

 

[jviehe]

Not to mention I would think it hard to believe that someone would think keeping time in their head is the safest way to calculate bottom time, vs a computer, or even just a watch. I'm sure you all remember trying tounlock the padlock at 100ft in AOW. Now count to 1800 secs at 100fsw.

 

[blackice]

cwinston once bubbled...
SDI/TDI does not require a thorough understanding of the dive tables, just their theory, at least not as far as I can tell from my class. They push computers heavily and leave tables up to the discretion of the instructor...

I would just like to add that I have taken TDI courses and they were very focused on tables and showed how to dive and not need a computer. They certianly didn't push computers.

Sure to dive with tables you do require some sort of depth and time montioring equipment. This does tend to be a computer of some sort, running in guage mode. But it doesn't have to be.

It makes good sense to have a computer as it is far more accurate at time keeping than a human underwater. And it is helpful for reviewing dives and profiles.

Maybe it's more about instructors and not agencies.

 

[blackice]

String once bubbled...
...The whole point of computers being invented in the first place was number crunching that would take a human hours.

People here are assuming incorrectly that tables are far safer and more accurate to follow than the algorythms in a computer. That isnt the case.

You have some good points there aobut the use of computer to make life easier for humankind.

But do note that as a diver moves into decompression diving, computer are not following as successfully as they did into recreactional diving.

Many tech divers have found that multi -gas computers have problems and give extensive deco requirements that are a long way off the required deco on tables.

This doesn't mean that they shouldn't be used but they are not (yet) as reliable as rec diving computers.

But in either case in the event that the computer breaks down or display's "Er" then the divers internal computer should still be able to work to enssure that the diver is able to make it out of the situation and surface safely.

 

[Uncle Pug]

String once bubbled...
show me a diver who can update his mental dive picture at 0.1 second intervals with accuracies to 3 decimal places throughout the entire dive

That is the silliness of dive computers... folks actually begin to think that is necessary.

 

[blackice]

Uncle Pug once bubbled...

That is the silliness of dive computers... folks actually begin to think that is necessary.

Well said, just let me see the mins that tell me which stop to be at and give me the seconds to plan when to leave and move up.

The rest of the space in the brain is looking for whale sharks and manta's