Dive Computer or Tables and console?

[BigJetDriver]

BJD,
My BIL is retired from NASA and working as a consultant and also a diver. One of my hobbies is the stock market. It was my extreme misfortune to be in Houston on my way to a seminar when the shuttle failed. We were literally at the breakfast table preparing to leave when the news flashed and all hell broke loose. Needless to say, we did not make the seminar. The deceased astronauts were all known personally by my BIL. What does any of this have to do with the original thread?? nothing...oh yeah..don't forget the dive watch, and depth guage.

Finnatic,

Although I did not know anyone in that group of astronauts personally, I respect them as fellow aviators, honor them as the explorers they were, and mourn their loss.

My comments simply had to do with the state of the art of computers, and the need for a newer and better space-going machine. NASA has the best people. They need better equipment to help them do a really tough job!

Cheers!

P.P.S.---I like a digital bottom timer and depth gauge with BIG numbers! Is easy to read, comrades!

 

[Uncle Pug]

You probably wouldn't be singing the praises of your 777 computers if all they calculated was altitude, time aloft and ttg... shoot lets be extravagant and say they even calculated range remaining at present fuel burn/airspeed.

Especially if critical inputs for a successful conclusion of the flight included the pilot's mental and physical condition, environmental parameters, and disposition of the passengers, among others.

The real REAL truth is that the computer can sample your position in the water column, mark the time, and re-calculate the deco requirements according to its built-in algorithm much faster than you, Uncle Pug, or me, or ANY human being. It can do the repetitive math MUCH faster, and with no mistakes.

Again, speed and accuracy of calculation doesn't mean much if all the relevant parameters are not considered. The fact remains that decompression science is so inexact that there is great variation between different brands of dive computers as well as dive software. User selectable levels of conservativeness can greatly alter the output. Unfortunately most computer users do not understand that this is so and just figure that the dive computer is accurate... when in fact the *accuracy* is far less meaningful than they can imagine.

This doesn't mean you are going to get bent using a dive computer... manufacturers must limit the profiles the computers produce to limit their liability. How much of the algorithm is driven by science and how much is driven by legal considerations?

I realize that I am speaking to the wind with this... but I like speaking to the wind.

 

[BigJetDriver]

I realize that I am speaking to the wind with this... but I like speaking to the wind.

Tovarisch Pug,

This may shock you, but I agree with everything you said in your most immediate post above!!

I certainly hope you are not just speaking to the wind. If new divers cannot understand the things you put forth, their computers may well rot a lot more than their brains!

Cheers!

 

[Uncle Pug]

Ah, you just want to log off and go to sleep!

Me to.

 

[BigJetDriver]

Ah, you just want to log off and go to sleep!

Me too.

Good idea, Ollie! G'Night!

BJD

 

[Uncle Pug]

G'night Stan.

 

[Wijbrandus]

I'm a relatively new diver, actually very new compared to the above posters, but I'll throw in my 200 psi as well.

I have no plans for a computer in the immediate future. Here's why:

1) I'm an air hog. My tank doesn't last to the NDL, and I don't do particularly deep dives. 70' is my limit so far, despite being AOW certified.

2) If I can't hit my NDL, then I can plan my dive via the tables or the wheel, and not sweat "losing" any bottom time.

3) Whenever I do get to the point I need a computer (and my air lasts that long), computers will have improved. Technology is improving at a dramatic rate these days, and the prices are only dropping.

4) Finally, when/if I ever get one, I'll know my tables so well I'll KNOW when that damn computer is pulling a HAL9000 and trying to kill me.

I repair computers all day long. The HAL9000 syndrome is well known to me. Never underestimate a computer's ability to fail you right at the moment you need it most...

 

[TX101]

Again, speed and accuracy of calculation doesn't mean much if all the relevant parameters are not considered. The fact remains that decompression science is so inexact that there is great variation between different brands of dive computers as well as dive software. User selectable levels of conservativeness can greatly alter the output. Unfortunately most computer users do not understand that this is so and just figure that the dive computer is accurate... when in fact the *accuracy* is far less meaningful than they can imagine.

This doesn't mean you are going to get bent using a dive computer... manufacturers must limit the profiles the computers produce to limit their liability. How much of the algorithm is driven by science and how much is driven by legal considerations?

I realize that I am speaking to the wind with this... but I like speaking to the wind.

.. And that exact same argument can be applied to the tables. After all, the computer algorithms are just derived from the tables.

The fact remains that computers give you more bottom time because they are calculating your dive, not a square profile. What happens if your narked and misread your bottom timer and only realise after you get out of the water? A computer would put in deco & safety stops that you wouldn't miss on ascent (due to audible alarms)

Of course, you would argue that you shouldn't get yourself into that sort of situation. But lets face it, it happens. I also don't "get" your argument of garbage-in, garbage-out. The dive computer simply logs depth & time and performs calculations on it's internal 'tables'. How can you get garbage in? If you are diving the tables, you are doing the same thing - loggin depth & time, except in your head. I would say that human error is much more likely to influence this situation than machine error, due to a while range of factors including experience, task loading and nitrogen narcosis.

It also depends on your type of diving. I have just started decompression diving in the last few months. I will cut a table using v-planner the night before. I will follow this table (plus backup tables for different planned depth/time) and use my depth timer. I also have two computers from different manufacturers as backup (ie. 3 depth timers total). However when I go to the red sea in September, Ill be relying 100% on my Nitek3.

 

[H2Andy]

I realize that I am speaking to the wind with this... but I like speaking to the wind.

not at all... a different view point always teaches me
things, and i very much respect your view point.

for me, it's a question of return on my investment. at this
time in my diving, my return on my investment is greatest
with a computer.

who knows, i may start cutting my own tables at some point;
i just dont' see that happening any time soon.

 

[pasley]

... I understand the benefits and flexibility of a computer offers, but which do you think would make me a better diver?...

Neither will make you a better diver. Good training and repetitive practice of your skills through diving often will.

Dive tables, if not used properly by a well trained diver who then follows them are not effective. Dive computers, if not used properly by a well trained diver who then follows them are not effective. Dive computers left hanging under the boat to complete the safety stop while divers enjoy a brewski on deck are notoriously ineffective and often blamed for ills that befall the owner.

Bottom line, you need to know how to work the dive tables regardless of what kind of diving you do. Computers and dive tables are not mutually exclusive. You use them together. Investing in a good computer is a great idea, but if funding is an issue not something you have to have on day one. Computers are expensive and dive tables are not. I personally would invest in a computer when funds allowed, but not required as your first investment.

I am a happy Cobra owner. But I also look at my tables.