Computers versus Tables

[zboss]

Big-t-2538 once bubbled...

you own a LDS don't you?

HA! LOL! No... but I do understand how to sell... I suppose!

Not to bring the PADI vs. everyone argument into this thread but let's face it - PADI has made diving accessible to a huge number of people that would never have gone into diving in the face of the requirements of some other orgs.

The higher number of divers particiapting in the sport means three things - convenience of choice in dive locations, equipment choices, and legislative lobbying for everyone regardless of their certifiying organization. It really comes down to getting people into the sport safely - if that means tables (which it doesn't necessarily) then so be it... but if it means computers then that needs to be addressed.

 

[ktarlecky]

I am tempted to throw my two cents in here but i am going on a dive vacation in 12 days with two of the debators here......Flying this one nuetral in public but i think both know where i stand.
Thinking about happy diving...happy thoughts!

 

[Rick Murchison]

Uncle Pug once bubbled...
no computer, no tables

Shame on you Pug! You'll give these youngsters the impression you're ignoring the safe envelope!
You and I and others who've actually done their homework have back-pocket plans that we know are well within the safety envelope - but their basis is in our knowledge of decompression theory - decompression theory as expressed in tables and computer programs. We didn't just pull the profiles out of thin air. That fact is so obvious to thee & me that it's tempting to say "no computer, no tables" but we must bear in mind some young soul may take it literally!
Love,
Rick

 

[Uncle Pug]

Scubatooth once bubbled...
hey pug where in PNW are you located ? near seattle ?

we like to think of Seattle as being in the Everett area.


Yes Rick... I'm mighty ashamed.

So let me say... most folks would probably be better off with a dive computer... but many folks could profit from just using a depthgauge/bottom timer and the appropriate air or nitrox tables.

Rick's right... unless you've studied deco theory and have played with decompression modeling software and have a firm grasp on what is going on and have good insurance... you should just stick with the tables or computers.

 

[Rev. Blade]

Uncle Pug once bubbled...

Snip...
Unless you've studied deco theory and have played with decompression modeling software and have a firm grasp on what is going on and have good insurance... you should just stick with the tables or computers.

I understand the argument that computers break, so you should plan your dive (on tables or a computer), so you CAN dive your plan.... Don't dive computers use "decompression modeling software"? I had assumed that the dive computer manufacturers used some sort of decompression theory in their algorithms. I'm pretty new to diving, (and I'm asking, not telling). What makes you more confident in the results of "decompression modeling software" from some source other than a (get it wet) dive computer?

By the way, I ran your multi level dive of 105' for 42 minutes past my SUUNTO software. (For the sake of the simulation I gave you 2 minutes to get to 105'. Then sixteen minutes at 105', a fast but safe accent to 40'. Ten minutes at 40', then a safe accent plus a three minute safety stop.) I was rather surprised how conservative the profile was, using EAN32. The same profile goes deco fifteen minutes in (thirteen minutes at the max depth) on air...according to my SUUNTO Dive Manager.

I figure you don't care much at all for the validation of some newby diver, but what do you have against the SUUNTO software (and all the other dive computers)? So far all my dives look about the same when downloaded, as when I was diving... i.e. how close did my dive get to the NDL. I bring my tables, in case my computer dies, but until it dies, I plan my dives on it. If it dies, I plan to rent a computer when I get back to the next shop that pumps air.... Assuming the shop can show me how to plan a dive, if they don't rent SUUNTO.

Blade

 

[Uncle Pug]

Rev. Blade once bubbled...
I understand the argument that computers break

The modeling software that I am talking about allows changes in the parameters of the dive to see how that effects tissue loading. I suppose you could play around with the personal settings on your Suunto but it really wouldn't give you the same educational value.

I think GAP is great for modeling as it allows you to see a graphical presentation of 16 theoretical tissue compartments fill and empty as you add time/depths to the dive.

I think Rick's objection is that unless you have some understanding of how depth/time load your body with inert gas then you should probably be using tables or computer... and he is probably right.

BTW... the way we did the dives I mention previously they could have been easily done on air... even though I use EAN32.

Oh... the argument that computers break isn't my argument.

 

[MikeFerrara]

Well, UP, we need to start that discussion on square profiles. Chad didn't start it like you asked him to.

 

[Rev. Blade]

Uncle Pug once bubbled...


Oh... the argument that computers break isn't my argument.

I'm sorry if it came off like my whole post related to your objections. I directed my post toward you, because I thought you were most likely to give an educated and measured response. (Feel free to take that as a compliment.) I was aware I was borrowing arguments from multiple posters.

Thanks for the hint toward GAP software. http://www.gap-software.com/ I'll download it and check it out. Free is one of my favorite prices... and this software has at least guarded endorsement by U.P.

The reason I bought a computer, was so I would be less inclined to "cheat" the tables. I know that the tables say that the whole dive counts as being at the deepest point of the dive. That doesn't really make much sense. If I drop to 115' for a couple minutes, then ascend to 40' for most of a dive, I don't want to be limited to 10 minutes of wet time (including my descent). I also don't want to simply say "forget the tables", without some research to back me up. I'm willing to play by the rules of a computer that takes into account how deep and how long I was down... even a conservative computer. I picked SUUNTO because it's a conservative computer. So far when my computer says I've been down too long, I come up... no matter how interesting the cuttlefish looked, or how big the lobster was. I hope to continue listening to the black box. For me at least, it makes good sense not to make up the rules as I go along, and I haven't yet learned enough gas theory to make my own tables.

I want bottom time, but don't want so much hospital time. (Hospital if yer lucky.)

Uncle Pug once bubbled...



BTW... the way we did the dives I mention previously they could have been easily done on air... even though I use EAN32.

...but I didn't know your dive profile. I picked a dive that was pretty aggressive (that still fit your stated depths and times), and I was surprised that it really wasn't all that close to the limits.

As I recall from some of your posts, you tend to dive an air profile, but dive EAN for an extra safety factor.

Blade

 

[Scuba Chip]

As a YMCA, NAUI, & PADI Instructor, I want to add my 2 cents to this discussion.
The YMCA has always been interested in teaching "skills" and the ability to use, interepret and understand the dive tables is definitely a "skill" that many certified divers simply don't have, among others.

Other agencies have generally taught students how to "use gear". This makes you dependent on the equipment. The dive equipment manufacturers love these divers. Just last Saturday (5/3/03) I met a certified diver who admitted to me that she cannot swim. She is NOT a YMCA certified diver.

No one makes money on labor and that includes your LDS. Money is made by marking a product up, and selling it. So instead of teaching and requiring buddy breathing for example, which requires time and expense to do, You simply sell a "safe second", "octopus", or whatever name you want to call it. It makes more money for the entire industry - LDS and manufcturer -takes less time, and makes the course easier to pass for newbies.

As a YMCA certified diver, I know that You are better trained than many AOW divers from other agencies. Having said that, I always dive with my computer (UWATEC Nitrox Z). But I always bring a copy of the U.S. Navy tables on every dive trip. I too know how to use them.

Computers are never a substitute for knowledge. They are a tool, a very useful tool. But they do allow You to maximize bottom times. Keep Diving!

 

[gkwaldee]

We learned on "square" tables, like everyone else i suppose. I quickly learned that 90 ft on a square left alot of time to do something else after a very short dive. Therefore, the next logical step was the wheel, which enabled us to understand the differences associated with a normal dive............i dont know anyone that goes straight to 90 and thats it.

I have just purchased a Atmos pro, pretty cheap, easy to use puter. Its good thru nitrox and that was a selling point for me. THe puter is MUCH more agressive than the wheel, when the puter still has me in the "green" the wheel has me in the higher PG's. This is something that we will have to play with to decide our comfort zone. The thing is that the tables dont take into account that you spent "x" amount of minutes getting to 90, just that you were there. The puter knows better how the profile went, and makes the adjustments to sat levels accordingly.

That said, I feel that (for me) using BOTH is the proper procedure. I plan the dive with the wheel, and then use the puter and my watch to ensure we dont get burned by watching the dots.....

I guess thats the point that we all learned first...........PLAN YOUR DIVE, DIVE YOUR PLAN. There are very few surprises that are good underwater.................but Im a newbie that wants to max BT, not max HT. Never been bent, but it dont sound fun at all.

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