PADI tables finally going away?

[AfterDark]

So, using someone else's computer to print out your tables for you to modify is ok, but using your own computer to print out your tables is not.

Care to explain the logic of that?

HUH? Are you confused? Using someone else's computer? What are you talking about? I don't even trust my own. What does Thanks but no thanks. I'll do it myself mean to you? When the Navy developed their tables they didn't use PDC's. Or any but the most prmitive computers that was many moons ago. My use of tables is probably far and away more conservative than any PDC. My perspective is I've been diving this way for longer than some posting here have been alive. I have never taken a hit. What I'm doing is right for me. Why should I change?

 

[Kingpatzer]

HUH? Are you confused?

Someone is.

Using someone else's computer? What are you talking about? I don't even trust my own. What does Thanks but no thanks. I'll do it myself mean to you?

I thought it meant you were going to use the Navy table which was calculated and printed using computers. Apparently you're going to instead derive your dive profile by hand from a series of complex equations. Sorry I misunderstood that.

When the Navy developed their tables they didn't use PDC's. Or any but the most prmitive computers that was many moons ago.

Ok, so you'll trust computer technology that's using vacuu tubes, and thus capable of very significant faults resulting from misrouting a wire on a panel, but you won't trust computer technology using microprocessors with self-health checks built into them and modern languages that preclude a myriad of subtle calculation errors? And who said anything about a PDC in my comment? I was simply pointing out that tables come from computers. So distrusting computer technology in favor of tables is frankly illogical.

My use of tables is probably far and away more conservative than any PDC.

I'm all for conservative dive planning. One need not have a conservative PDC in order to plan a conservative dive. Just as one can modify a table to be even more conservative, one can choose not to ride the edge of the NDLs on a PDC. Or has that thought not occurred to you?

My perspective is I've been diving this way for longer than some posting here have been alive. I have never taken a hit. What I'm doing is right for me. Why should I change?

No one is saying you should change. I am saying that luditism is not the basis of a valid argument for pedagogical choices by agencies teaching in first world countries.

 

[AfterDark]

No problem, I'm not the most skilled writer. I apperciate a little slack, thanks.

No. I trust the fact they used data from sponge divers that had been diving deep and long for years and had a record of divers taking DCS hits. In addition to that navy divers were used in the development of their tables . Real people doing real dives taking real hits. A method that they probably couldn’t do today. When they were done they had REAL DATA from REAL PEOPLE doing actual diving. Yes I trust that more than computers. Where do you think all the data used for the foundation of modern tables came from a computer? No, it came from the efforts and sacrifices made years ago by people that have been long forgotten.


I realize your not asking me to change. I mention the time I've been used this method as an attempt to show that it is a tried and true method that works over a long period of time. As they say the proof is in the pudding or in this case the diving.
I don’t berate anyone for using only a PDC. I couldn’t care less what anyone uses for their dive timing needs.
I just think like others posting, that knowing another method (tables) is a plus and makes for a better all-around diver. Knowledge in this case is more than power it’s safety.



I modified my use of the navy tables because when I was taught to use them it was drummed into me that the people they used to develop the tables were in much better shape than me and may have required less deco. So over time whenever I did a deco dive (before PDCs) I'd add time to the last stop and record the time for use again later and as a base for what worked. Diving in the 60's and 70's was nothing like it is today. We had to work a lot of things out ourselves.


I’m off to make a deep dive before I go to Morehead NC. The operator wants to see one deep dive in the last year and last year I dived above 70fsw all year. Target depth today is 150FSW.

 

[caseybird]

Am I? Have you read the Suunto paper on the model they use? The degassing theory they use is actually different from the traditional, or it is a updated version if you like, and would change the way you ascend and degass, also they consider that changing depth during the dive hardens degassing and take that in account for theirs model, contrary to other models in which you extend you NDL by varying depth, more precisely it give you less credit for changing depth.

OK, Deal: I'll read your paper if you come up with ONE example of a diver who has been bent on an NDL dive guided by a Sunto computer, during a dive with a buddy using a different computer model.
Conditions are:
No NDL limits were exceeded on either computer.
ascent speeds were within standard guidelines. (30' per minute)
No underlying conditions, (PFO, heart disease)
Decompression sickness only, no AGE from rapid or breath holding ascent or other scuba related injury.
Minimum 3 minute safety stop. (unless you can demonstrate that one computer omits it)
Conservative gas planning.

Thanks

 

[boulderjohn]

I can guarantee you that in most cases, if I read something, I understand it. Specially when the matter is not that complicated, as it is the case.

Let me try to clarify then, I think the best way here being quoting the Suunto paper. Forget a second about the NDL time mark, I am talking about ascension here, or rather, Suunto is:

Quote Originally Posted by Suunto
Traditionally, since Haldane’s 1908 tables, decompression stops have always been deployed in fixed steps such as 15m, 12m, 9m, 6m and 3m. This practical method was introduced before the advent of dive computers. However, when ascending, a diver actually decompresses in a series of more gradual mini-steps, effectively creating a smooth decompression curve.

As you can see, according to the Suunto model, ascend do differ from the traditional way, thus two buddies with Suunto and other model would have to ascend in different ways as gradual ascension and fixed step ascension can't be reconciled as there is no way to ascertain which one is the 'most conservative'.

The section you are quoting compares old Haldanean thinking with newer thinking. It does not say that someone using tables in no decompression diving ascends in a series of stops. If someone is diving the PADI tables, they are told to do a continuous ascent until they do a 3 minute safety stop, exactly as the Suunto document says you do it with a Suunto computer. I dived about 300 dives with a Suunto Cobra, and it had me do exactly that. When you reach the 19 foot mark, it starts counting off a 3 minute stop.

These is no difference between the way a table diver ascends and a computer diver ascends on a no decompression dive. Things are different with decompression diving, but we are not talking about that.

 

[Quero]

The section you are quoting compares old Haldanean thinking with newer thinking. It does not say that someone using tables in no decompression diving ascends in a series of stops. If someone is diving the PADI tables, they are told to do a continuous ascent until they do a 3 minute safety stop, exactly as the Suunto document says you do it with a Suunto computer. I dived about 300 dives with a Suunto Cobra, and it had me do exactly that. When you reach the 19 foot mark, it starts counting off a 3 minute stop.

These is no difference between the way a table diver ascends and a computer diver ascends on a no decompression dive. Things are different with decompression diving, but we are not talking about that.

True. And not only that, but divers using a computer model other than a Suunto computer also do a continuous ascent. I am aware of no dive computer that calculates ascents in three-meter increments as the old Haldanean model described in the Suunto document. Therefore, divers using different computers do ascend in together, as long as they are doing no-decompression diving.

 

[windapp]

Some of theses posts are making me think that some of the posters are using their computers to do decompression dives. If this is the case, you are putting yourself at serious risk. Compressiion diving is extremely dangerous, and compression diving without proper training is suicide. Recreational dive computers only have compression modes built in to get you to the surface safely in the event that you accidentally over-stay your ndl (no real excuses for this) or that an emergency situation keeps you down longer. Even tech divers don't do more than one decompression dive in a day.

 

[Blackwood]

Even tech divers don't do more than one decompression dive in a day.

Who told you that?

 

[AfterDark]

Some of theses posts are making me think that some of the posters are using their computers to do decompression dives. If this is the case, you are putting yourself at serious risk. Compressiion diving is extremely dangerous, and compression diving without proper training is suicide. Recreational dive computers only have compression modes built in to get you to the surface safely in the event that you accidentally over-stay your ndl (no real excuses for this) or that an emergency situation keeps you down longer. Even tech divers don't do more than one decompression dive in a day.

Where were you in the 70's and 80's when we were doing deco dives? OMG I never realized we were in such danger! All the hours in the water my life hanging by a thread if I'd only knew. Well it's too late now, I guess I'll just keep risking my life by doing deco dives with the navy tables for air. Woo is me.

 

[Brendon]

Anyone want to borrow my old scuba pro decompression meter (bendomatic) LMAO... AfterDark, I hear what your ur saying. As I agree, however as a whole we have kind of moved away from that for increased margin of safety in the recreational realm... I was taught by John Manlove, Willie Wilson and Drew Ruddy all renown navy divers, decompression was just a way of life then even on the recreational side. Now the knowledge is there for safety as a backup not a primary plan, at least for me and those I teach.