computers & tables: split from ow vs aow

[GoBlue!]

I'm curious how all members of the "who would ever need a table when computers are so darn foolproof" crew are reacting to the Suunto recall?

Jim

 

[pilot fish]

I'm curious how all members of the "who would ever need a table when computers are so darn foolproof" crew are reacting to the Suunto recall?

Jim

Thinking, I'm glad I have a backup puter.

 

[sharpenu]

The same thing I think every time a reg is recalled.

1 Comps are still more accurate than people. Especially at depth- EVERY diver is narced to some extent on EVERY dive.

2 People make simple math errors all the time. Ever bounce a check?

3 SCUBA is inherantly an equipment intensive sport. Your life depends on your life support equipment. Reg, computer, mask, BC. I had a mask failure once. It doesnt mean I should stop using one.

4 Undeserved hits still happen, table and computer alike. They are the exception, not the rule.

5 That being said, tables are safer than computer. Not because of the computer, but because of the rounding done on tables. 63 feet becomes 70, 52 minutes becomes 55, etc. They are just more conservative. Worried?? Then always surface a bar or 2 into the "green".

Every day of diving costs around $90. If I dive 60 or 90 minutes, is the difference between table and comp. I want the most for my $$$$. Could you do this profile set on tables? (all EANx36)
Dive 1: 67 fsw, 51 min......SI 34miin
Dive 2: 62 fsw, 61 min......SI 57 min
Dive 3: 62 fsw, 48 min

Every table I have puts you well into DECO with dive 2. These were no deco with my comp. THAT is why I dive it.

Oh, BTW, for those that back up the comp with the tables, how do you back up the comp with that profile? Would you still consider this a no deco dive?

 

[MASS-Diver]

Every day of diving costs around $90. If I dive 60 or 90 minutes, is the difference between table and comp. I want the most for my $$$$. Could you do this profile set on tables? (all EANx36)
Dive 1: 67 fsw, 51 min......SI 34miin
Dive 2: 62 fsw, 61 min......SI 57 min
Dive 3: 62 fsw, 48 min

Every table I have puts you well into DECO with dive 2. These were no deco with my comp. THAT is why I dive it.

Oh, BTW, for those that back up the comp with the tables, how do you back up the comp with that profile? Would you still consider this a no deco dive?

I would not be comfortable doing those dives as listed. You can get away with all sorts of weird stuff with computers, that is untill the day you don't. I hope you are at least doing nice slow ascent and saftey stops.

 

[sharpenu]

You can get away with diving the tables until the day you dont. That is my point. Undeserved hits still happen.

My question is: What science or evidence can any of you provide that computers are unsafe? I am talking about real evidence. Anecdotal evidence does not apply here. For every story of a computer error, I can offer a diver who got bent on the tables. Computer malfunctions boil down to one of the following reasons:
1. Poor maintenance (including not changing batteries)

2. Operator error

Like I posted above, the only reason tables are safer is the fudge factor. A 63 foot dive becomes a 70fsw on the table, a 50 minute dive is rounded to 55. Otherwise, computers function exactly as designed and malfunctions are rare. I have seen more regulator failures than computer failures. To be safe, I have 2 computers. One is the Aeris 500AI, an Aeris wrist comp and a backup SPG. This has reduced even that small risk to essentially zero.

 

[GoBlue!]

What science or evidence can any of you provide that computers are unsafe?

None that I'm aware of. I've always simply argued that no one has established that computers are SAFER, which some people like to claim.

Computer malfunctions boil down to one of the following reasons:
1. Poor maintenance (including not changing batteries)

2. Operator error

3. Internal software error (see recent Suunto recall)

4. Hardware error, not related to maintenance.

Like I posted above, the only reason tables are safer is the fudge factor. A 63 foot dive becomes a 70fsw on the table, a 50 minute dive is rounded to 55.

So you have evidence that tables are safer?? Interesting.
Can you cite it? Can't just say "common sense," because one could theorize that operator error with tables may surpass operator error with a computer, which could potentially negate the "fudge factor" you refer to with tables (which, obviously, is much more than just "rounding" depths....it's also assuming all dives are square profiles).

Let's just say that there is no evidence that tables or computers are superior to the other, and errors with either can lead to potential harm. Claims that certain types of errors are "more likely" or "less likely" with either are unfounded, to my knowledge.

Jim

 

[pilot fish]

None that I'm aware of. I've always simply argued that no one has established that computers are SAFER, which some people like to claim.



3. Internal software error (see recent Suunto recall)

4. Hardware error, not related to maintenance.



So you have evidence that tables are safer?? Interesting.
Can you cite it? Can't just say "common sense," because one could theorize that operator error with tables may surpass operator error with a computer, which could potentially negate the "fudge factor" you refer to with tables (which, obviously, is much more than just "rounding" depths....it's also assuming all dives are square profiles).

Let's just say that there is no evidence that tables or computers are superior to the other, and errors with either can lead to potential harm. Claims that certain types of errors are "more likely" or "less likely" with either are unfounded, to my knowledge.

Jim

What is asserted, my postion too, is that computers are more reliable than tables done by a diver on a boat, or at depth. I would feel more comfotrable, I think a lot of divers would, with the computations of a dive computer than a diver's plodding through tables. Nothing wrong with the tables themselves, it the figuring and potential for error that is the problem with the use of them.

 

[lamont]

What is asserted, my postion too, is that computers are more reliable than tables done by a diver on a boat, or at depth. I would feel more comfotrable, I think a lot of divers would, with the computations of a dive computer than a diver's plodding through tables. Nothing wrong with the tables themselves, it the figuring and potential for error that is the problem with the use of them.

I'd feel more comfortable if divers understood the theory behind decompression. They should understand the computations behind what the computer is doing. They should also understand the models and computations that were done to create the tables as well. I would also be more comfortable if divers knew what to expect on any given dive and didn't just dive until the computer counted down to zero, or went into the green, or whatever. I don't have any evidence to prove that diving by entirely trusting the computer is more dangerous or unsafe, but I think its obvious that it is.

The scale of computer use at my work (admining 10,000+ servers) pretty much requires that I treat computers defensively. I guess I just can't understand anyone who would unthinkingly trust a computer with their life if they had another choice.

 

[sharpenu]

Blue- point taken. I dont have proof that tables are safer. And I should have said that the vast majority of computer errors occur.... you know.

BTW- I dive a gas integrated computer exclusively. (most of the time with a backup comp and SPG)

Lamont-
You trust your life to computers EVERY DAY. From the ABS in your car, to the air traffic control center to your doctor's office, computers control or at least play a part in your life on a constant basis. I disagree that you need to understand the math to use it. A musician does not need to mathmatically understand sound to play a symphony, a man need not be an automotive engineer to drive a car and the vast majority of divers don't need to be able to design a dive table to use a dive computer.

 

[ZenDiver]

You guys need to quit arguing and go diving. I once went diving with a guy who never used tables, a watch or computer. I asked him how he knew when it was time to come up to which he replied, "When my air runs low." You could imagine my alarm. He said, "I have been diving this way for over 25 years and I aint got bent yet, so whats the difference?" I was rather nervous at this point so I said that I will call the dive when we get close to deco. He said "Fine, whatever you want to do." So we do the dive and I am just getting settled in to it when 16 minutes later on a 50 foot dive he comes up to me and says its time to go up. He was at 500 psi, I on the other hand was at 2300 psi. We surfaced and I asked if he had a leak or something in his equipment. He says, "Nope, that was actually a pretty long dive for me." :11: So there you go, this fella never needed to use tables or computers because the longest dive he ever had was less than 20 minutes on a 60 foot dive. No watches, no tables, no computers, no nothing. I have yet to dive with him again.

Brian