Another Tables vs. Computers Thread

[Soggy]

That's not entirely true, now is it? Don't they rely on Deco Planner and what not BEFORE the dive? It still smacks of a lot of ego to me: you don't but you do type thing.

Christ, lay off the ego crap. It has nothing to do with EGO. I don't understand why you are so threatened by this. I think you may be the one with the ego problem...in that it seems very fragile.

Ugh....

They may play with deco planner or vplanner ahead of time, but those caves are being *explored* thus the depths are unknown. Obviously, we need to derive our plans from *somewhere*, but the point is that a simple table can be used and is more flexible than a computer, especially once you begin to move beyond simple recreational diving.

If you believe people are choosing to dive with bottom timers because of ego, you are sorely mistaken.

EDIT: Actually, if you do some reading on the WKPP site, you will see a lot of talk about decompression curves, O2 window, etc. Most of this stuff is derived on the fly without any software.

 

[H2Andy]

i don't see a difference between planning a dive using a table, a PC, or a
dive computer.

it does seem odd that some guys say "i don't use a computer in diving" and yet
cut tables before every dive ... with a computer

of course you use a computer. and then follow a table calculated by
a computer.

what's the difference between that and planning a dive with a computer, but then
following a constantly updating table (i.e. the computer)?

that the computer may malfunction? well, then you have your table
with you, and you follow that instead.

 

[minnesota01r6]

a simple table can be used and is more flexible than a computer, especially once you begin to move beyond simple recreational diving.

What does any of this have to do with using a computer to train OW divers as opposed to tables? Every comment I have read that says you shouldn't use a computer references dives to 300' or trimix or cave dives or the fact that they have a bazillion logged dives and could dive blindfolded without a spg. Those instances are about as related to OW dive training as me taking a shower.

EDIT: And yes, your ego does have something to do with it, because you are arguing from a standpoint that centers around the way YOU dive, not the way others may choose to dive. The OP asked a question about training OW divers, not trimix or cave diving. When diving within recreational limits, a diver of average intelligence can safely be trained to plan and execute a dive with only his dive computer. If it fails, they thimb the dive. They may be inconvenienced by this, but it is a tradeoff they make for the convenience of not needing to track pressure groups, etc.

 

[Soggy]

Ok, let me clear a couple things something up...

1) Using ratio deco, for non-extreme profiles (short dives in the 100-250ish) range, one can easily derive a decompression profile from 'thin air' with no computer involved at any stage of the game. None of it is rocket science and it is explained in various places throughout the Internet

2) I have a book of laminated air tables printed from deco planner ranging from 80ft-180ft. I get on the boat, and derive my profile from those tables based on knowledge of how the various gasses I use affect the numbers on the table. For dives in the 150' range using 21/35, and 50%, this can be as simple as dividing by 2. Not rocket science. This becomes my default plan for the dive.

3) In the water, I keep track of my average depth in my head. If it differs much from my default plan, I'll go into my tables, usually at the first deco stop, and adjust the plan, or just adjust it based on a little bit of understanding on how to shape the ascent using the gasses I dive.

None of it is complicated nor requires an immense amount of brain power.

So, yes, I guess at the very origin, if I'm not using ratio deco, my tables were derived on a computer, but this is clearly different than diving with a computer on your wrist. It is also much more flexible as it can be applied from OW 60 ft reef dives all the way to expedition level trimix dives. This is the law of primacy. Learn it from the beginning, it becomes 2nd nature, and you can build on this foundation.

Yes, I know I was referring to technical diving here, but can't you see how, if it works in a technical diving scenario, it would work in recreational diving which is much less complicated?

i don't see a difference between planning a dive using a table, a PC, or a
dive computer.

it does seem odd that some guys say "i don't use a computer in diving" and yet
cut tables before every dive ... with a computer

of course you use a computer. and then follow a table calculated by
a computer.

what's the difference between planning a dive with a computer, and then
following a constantly updating table (i.e. the computer)?

 

[limeyx]

i don't see a difference between planning a dive using a table, a PC, or a
dive computer.

it does seem odd that some guys say "i don't use a computer in diving" and yet
cut tables before every dive ... with a computer

of course you use a computer. and then follow a table calculated by
a computer.

what's the difference between that and planning a dive with a computer, but then
following a constantly updating table (i.e. the computer)?

that the computer may malfunction? well, then you have your table
with you, and you follow that instead.

But that doesn't cover it. There is at least one possibility you dont cover, and that's how I actually do it.

Imagine that you (or "one") ran a piece of deco planning software (gasp yes, using a computer) and they ran it for a range of bottom times, range of depths, range of "conservatism" factors, and different numbers of dives per day and days of diving.

Then say that certain patterns started to become apparent in the profiles that were coming up. However, maybe you had to make some simplifying assumptions to find those patterns (say using a standard set of gases and not custom blending for the depth you were going to).

Then dont you think that (maybe) it's feasible to come up with a set of guidelines for a useful range of dives that give you some "rules" to generate profiles for those dives that do not directly use a computer? Yes, the profiles are derived from the output of (many runs of) a computer program but it's not the same as taking the output of decoplanner and running the dive like that.

Then say you look at these patterns, dont you think it might be feasible to modify your decompression plan/ascent profile during the dive if you want to cut the dive short, or the wreck is shallower than you expected?

would you admit that maybe that's feasible?

and could you also accept that maybe some agencies disagree with the way certain gases (namely Helium and the narcotic behavior of O2 ) and that dive computers and maybe even tables dont factor those things in? And that maybe since the understanding of those things is so fluid, that maybe it's easier to generate a base set of tables and "massage" the numbers based on the current understanding?

If you want to call that diving tables or with a computer then fine -- maybe we all understand the same thing but are calling it by a different name.

All the profiles I dive are definitely derived from data that at some point has come out of some kind of deco software. But derived does not mean the same as.


In terms of the dive planning for a specific dive, I honestly do not use a printed table or a computer directly for a wide range of profiles. There are some dives that I am trained for that I dont do very often (an example would be a decompression dive at recreational depths -- say 60 mins at 100 feet) that I would have to think about a bit more and might generate a table that I then modified to suit my needs. I still dont take the table with me.

 

[limeyx]

Ok, let me clear a couple things something up...
...

amen. You know you're going to die if you do it that way, right?

 

[The Chairman]

but I am not going to post it here because I do not want to be responsible for someone getting injured.

Oh the irony! Is it safe or not?

 

[Soggy]

Oh the irony! Is it safe or not?

Not if you don't know what you are doing, just like diving tables or computers or scuba isn't safe if you don't know what you are doing, which is why giving people as much information as possible in classes is so very important.

 

[H2Andy]

and could you also accept that maybe some agencies disagree with the way certain gases (namely Helium and the narcotic behavior of O2 ) and that dive computers and maybe even tables dont factor those things in? And that maybe since the understanding of those things is so fluid, that maybe it's easier to generate a base set of tables and "massage" the numbers based on the current understanding.

Yes, I know I was referring to technical diving here, but can't you see how, if it works in a technical diving scenario, it would work in recreational diving which is much less complicated?

all i can say is that i am not nearly experienced enough to engage in that
type of diving, and may never be (i don't have a mathematical mind)

whereas i feel very comfortable ("close enough to fine") with deco software
and a computer.

but, you know, as i continue to dive, i'll start nosing in that direction and hey,
maybe i'll be able to "get it" and feel safe using it. i certianly would not
try it at this stage in my diving.

 

[The Chairman]

Christ, lay off the ego crap. It has nothing to do with EGO. I don't understand why you are so threatened by this. I think you may be the one with the ego problem...in that it seems very fragile.

Pride and arrogance (aka ego) have killed more people in this sport than just about anything. IT IS YOUR ENEMY. Only a fool would contend otherwise. But sometimes people just can't handle the truth.

GI3 has been known to pull tables out of his butt. So what? You won't catch me following tables built on a gut feeling. That turns a SWAG (Scientific Wild Arse Guess) into a DWAG (Delusional Wild Arsed Guess)! The former is bad enough!