Computers vs. Dive Tables

[Mr Carcharodon]

I seen many on here say that depth averaging can't possibly work. What I have seen people say is that it is not just a simple average, and while it may be a good technique, it requires training and should not be attempted without proper training. An important distinction, if you ask me....

Are there any techniques used to avoid DCS that do not require training or thought? In that respect this one does not appear to be much different than the others.

 

[Mr Carcharodon]

If you are talking about the computers vs tables in general, I still don't think the statement is correct, because the algorithms used in both vary considerably, depending on the supplier.


*.

Fair enough. However my computer, a Suunto, is conservative reletive to the tables. There probably are differces in other computers. But based on comments from other divers I would say in generals computers are realatively conservative. That is not to say that there may be exceptions.

 

[Tollie]

Donnad,

A word of advice... dont learn how to do dive planning from the internet. A run of 4/5 dives per day over two days is a lot of diving.

You can plan the dives (multiple dives) using the tables... be sure to give yourself plenty of SI padding.

If nitrox is available you might wish to take advantage of the opportunity to learn how to use enriched mixtures.

Dont expect the computer to do your thinking for you. Please dont dive the limits of either the tables or the computer.

 

[JimC]

Many computers on a squarish profile are significantly more conservative than tables.

You can thank the lawyers for that one.

 

[Debay777]

im not even certified yet....about a week before my first class!!!!!!........and this topic sounds like beating a dead horse. If the computer accurately measures the amount of nitrogen your body is absorbing/releasing, and can lengthen your dive time then it sounds like it would be hard to plan a dive. from all i have learned, you should make a dive plan, and stick to it. never deviate. if you use a computer and you find that your dive can be extended by 5's or 10's of minutes and you take them, arent you deviating from the plan? what if you have support in the boat and they are expecting you to bubble up in a cetain amount of time? i know im a newb, but it seems like the computer is a mixed blessing. I guess if you can digitaly plan your dive with the computer, and it will factor in the depths and allow for you to use the extra time you would have lost using a square chart plan then you are ok. but what if you dont?

 

[donnad]

thankyou. the first day will be up to five dives, the second day probably only two, possibly three. we will have mandatory 2 1/2 SIs

 

[DivesWithTurtles]

... If the computer accurately measures the amount of nitrogen your body is absorbing/releasing, and can lengthen your dive time then it sounds like it would be hard to plan a dive. ...

I'm not going to address your questions (sorry), but, as a new student, I do want to emphasize to you that a computer does not measure the amount of nitrogen your body is absorbing or releasing. See Tollie's post above:

Just as an aside. Neither computers nor tables are really “accurate” measures of nitrogen uptake in your body. Both provide estimates based on theoretical assumptions and models. Your personal status will be effected by (in addition to time at depth) your ascent profile, environmental conditions (cold), how hard you may have worked under water, how much you may have drunk the night before… and your own biological/physiological condition.

So… for me bottom line. Dive with your head in addition to any other aids you may use (tables or computer).

And add the very important factor of staying well hydrated!

 

[MikeFerrara]

im not even certified yet....about a week before my first class!!!!!!........and this topic sounds like beating a dead horse. If the computer accurately measures the amount of nitrogen your body is absorbing/releasing, and can lengthen your dive time then it sounds like it would be hard to plan a dive. from all i have learned, you should make a dive plan, and stick to it. never deviate. if you use a computer and you find that your dive can be extended by 5's or 10's of minutes and you take them, arent you deviating from the plan? what if you have support in the boat and they are expecting you to bubble up in a cetain amount of time? i know im a newb, but it seems like the computer is a mixed blessing. I guess if you can digitaly plan your dive with the computer, and it will factor in the depths and allow for you to use the extra time you would have lost using a square chart plan then you are ok. but what if you dont?

There are various ways to plan and track dives. I don't care to debate the advantages of computers vs tables, depth averaging, profiling ect but...often, it's important that a dive plan be flexible to some extent. Why shouldn't it be? We need enough gas to complete the dive and we need to be prepaired to complete any required decompression or avoid any but, aside from that, why shouldn't er be able to decide to stay longer. leave earlier or turn left rather than right? The purpose of the plan is to help insure that we get back. As long as we see to that, why shouldn't we have some flexibility?

 

[mobster75]

im not even certified yet....If the computer accurately measures the amount of nitrogen your body is absorbing/releasing,

I just had to comment on this... A computer has no idea how accurately YOUR body is absorbing/releasing nitrogen... Computers are all based on models on nitrogen absorption (same as the tables) and we all have factors that will either shorten or prolong the calculations...

For my diving, I'm 6'0" and 250 lbs which is overweight and indicates higher fat content while it will contribute to slower off-gassing of nitrogen. Which means even if my computer tells me I have 20 minutes of NDL time left, I should still surface pretty quickly..

The way I see it, each diver needs to understand where the theoretical textbook calcs come into play and where we each sit in relation to the "textbook example" and adjust accordingly...

But the computer NEVER, EVER is an "accurate" model of nitrogen loading unless you have some crazy super-experimental bionic implant.

 

[Debay777]

I stand corrected. I guess I said what I was thinking, not thinking about what I said. I understand that the computer is all about averageing. I know its programmed to factor in a safe calculation so that you dont push your limits. My real point is that -- and i freely admit that once im diving outside of class this may change with experience-- if you have a dive plan, you should stick with it. if there are people in the boat waiting for you, they dont know if you are hurt, stuck, or dead. if you get seperated from you dive partner and they stick with the plan and surface, then you are alone, and they are wondering where you are. I know its worse case scenario planning, but thats what its all about. Again, I admit that if once im certified and i get some experience under my belt that i may end up getting a computer and using that extra time, who knows. it just sounds like a gamble to me.