A disturbing PADI rumor

[Norm]

I've been hearing this rumour for several years, (not against any particular agency). I do not buy it. I own three computers but my deep dives are always table-based, using the computers solely for backup. I have had several computers to "wig-out" during a dive! I think everyone should know how to use the tables. Just my opinion.
Norm

 

[wannabe]

For us cold water divers we have a very easy way to stay within the tables using a simple SPG it is called a Al80.

I am not great on extending my air consumption but I do better than the guys I dive with and everytime I start getting close to limits it is time to head upwards because I am getting low on air.

Computers have good reliability of which I will bet on over human calculations anytime. Tables are handy but if you know the dive site (depth) and aren't packing big air you will have trouble smoking the tables too badly. Even boat diving where you will have the 'squarest' profiles you still often have bottom desent and ascent in getting to areas of interest.

 

[KidK9]

I would actually like to comment on this subject. I'm a FAIRLY new diver, I give others the benefit of the doubt. But I believe that others that frequent this board are very well read and intelligent people. Have you took advanced classes of any sort? If not, have you at least just ridden on a boat with others? The general scuba public, IN MY OPINION, is not as well educated as they should be. "Hey fish are cool, maybe I should be an unintelligent idiot and breathe underwater". I'm sure, most of you can relate a bit. Why buy a calculator and not know what its basic functions are. Bad mishaps happen. Think about it. I think it's dumb not to teach fundamentals of physiology just b/c it bores most people. HEY IT MAY BORE YOU BUT YOU NEED TO KNOW IT. NOT EVERYTHING IS CHASING CORAL AND NURSE SHARKS.

 

[wannabe]

A car can kill you if you don't operate it properly.... do you completely understand how it works?

A quick run down of why is all you will need for basic training, if you get curious (more involved in diving) you will do more research to better understand risks involved.

Back to my car analogy-- you didn't know everything when you were 16 and first got your licence but were allowed to drive. As you got older you learned more to become more proficient as a driver.

I think the information presented in most beginning dive classes is overly technical for most people and makes them gloss over to very important concepts. Since I don't belive they will simplfy instruction to make it make sense for a person of average technical/physiology knowledge understand teaching how to read a computer and staying to an smaller tank volume are better safeguards IMHO.

 

[KidK9]

Your car analogy is a good one. I'm not saying that people need to understand the algorithms used, but they do need to understand the basic computations and why they are there. IMO, it's just being safe. Knowledge is more than power, it's also safety.

 

[Butch103]

Sounds like Chicken Little is running loose again...............Folks look before you leap................

 

[Mike Newman]

This has been an interesting topic - for a probable red herring!

How serious would it really be to YOU if PADI did drop the tables for OW? It doesn't mean that you have to stop using them. And I'm darned sure that I will - even if I start to use a computer, when my budget allows the investment. Someone said it already - plan your dive, then observe your computer.

If the issue is how much can you rely on a buddy who didn't understand the tables - the answer, where your dive safety is concerned, is as much as you choose to. Either diver can call a dive off - and if you've applied your training correctly, and you're up to your pre-ordained dive limits, up the pair of you go.

Is it very likely that the tables are going. About as likely as being hit by a meteorite during your next dive, I reckon.

 

[padiscubapro]

Walter I had a long reply to this thread including various tables (it took over 15 mins)but this board times you out too quick webmaster please fix this!..

The basic jist was that you are incorrect about DSAT eliminating all compartments longer than 60 minutes.. DSATs m value table is a 14 compartment model, the longest compartment being 480 minutes.. Padis 24 hour recommendations seems to be based on their compartment 12 which is 240 minutes..
I guess they feel compartment 13 (360 mins) and compartment 14 (480) minutes rarely comes into play.

Buhlman models (zh-L12 and dh-L16) have the last compartment at 635 minutes.. dcap model is around 680 minutes if memory serves me

 

[Walter]

padiscubapro,

"you are incorrect about DSAT eliminating all compartments longer than 60 minutes.. DSATs m value table is a 14 compartment model, the longest compartment being 480 minutes"

I never said DSAT eliminated all compartments longer than 60 minutes. What I said was in direct reference to PADI's RDP, not the model it was based on, "They eliminated all compartments (tissue group is a misnomer) with half times over 60 minutes." That was in direct response to your statement, "Padi did back off the limits on compared to the Navy tables, but the being more liberal on repetive dives is due to the fact that they eliminted one of the very long tissue groups from their calculations"

You are correct in understanding "Remember it takes about 6 half times to saturate/desaturate compartments.. so a 2 hour compartment would take 12 hours to saturate" a 60 minute compatement takes 6 hours to saturate or desaturate. If the RDP had any compartment longer than 60 minutes included the time to clear would be longer than 6 hours.

 

[padiscubapro]

Walter,
I'll go with you on this one.. mostly.. Padi makes it appear that they use a 60 minute model due to the 6 hour time to "a" diver.., But PADI never states you are gas free(in fact they say the opposite with their time to fly rules), just that under normal RECREATIONAL dives slower compartments do not come into play.. Which is basically what I've been saying all along I think its more of nit picking than anything else.. AT least the less informed could get something out of this discussion which is waht the board is about.. not who is right and who is wrong.. besides noone knows anything for sure about deco anyway.. and this whole discussion is based on neo-haldane models, we haven't even discussed bubble theory yet