A disturbing PADI rumor

[padiscubapro]

Originally posted by Walter
funky__monks,

Try to be fair. There's no reason to get upset over a rumor. If it later turns out to be true then would be the time to get upset. Get upset over real issues - there are certainly enough of them around.

"I've already spent much of my time since taking my OW course trying to learn the why's to what was taught, learning what I wasn't taught, and learning the "other side" to things that I was taught to be fact when in actuality it was propoganda based."

Good for you. I'm interested in hearing what was left out of your class that you believe should have been included. I'm also interested in what was presented as fact that turned out to be propaganda.

"or any knowledge of what the algorithms in the computer your using is based on, is the most asinine thing I've ever heard."

It is my guess that most divers regardless of what course they went through fall in that category. What per centage of divers do you think understand half-times, compartments, M values or the difference between Haldanian, modified Haldanian and non Haldanian models? I teach a pretty complete class, but I don't cover those topics. Most divers blindly believe it when their instructor told them the RDP is more conservative than other tables when the opposite is actually true. I agree divers need to understand how to use tables, but I don't think they need to understand how they are designed.

48 minutes at 80 ft (there is no 77 ft on the tables) gives you a 23 minute decompression stop at 10 ft on the YMCA tables. On the DCIEM tables you need 5 minutes at 20 ft and 10 minutes at 10 ft. NASDS gives you 19 minutes at 15 ft The RDP and the MDEA tables won't even give you info for blowing the tables by that much, PDIC gives you 10 at 10, NAUI gives you 10 at 15, BSAC only requires 3 at 6 meters (20 ft).

I went through that to ask how understanding the tables helped you on that dive? Seems to me you ignored the tables and blindly followed your computer.

I could be wrong, but I don't expect PADI to remove tables from its standards. If they did, how would not understanding table use make a diver less safe than the example you used of yourself diving a computer when you do know how to use tables?

padiscubapro,

"PADI's DSAT spent alot of money developing tables"

I have no numbers, but don't you think they've turned a profit on that deal yet? They started selling the RDP back in 1988. They've sold lots of tables in 14 years. They were getting hit by bent divers with product liability law suits for selling US Navy Tables. Lots of folks were pushing the tables and getting bent - especially on repetitive dives. I never did understand their response - they came out with tables that were more conservative on the first dive and much more liberal on repetitive dives. Other agencies saved the research money and merely backed off the US Navy Tables which resulted in more conservative tables than either the US Navy or the RDP. Kinda makes you wonder........

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 (whick really only comes into play on very long shallow dives) and allows the diver in longer for shorter intervals.. The absolute M values are still however less than the navy tables allow..


Shorter surface intervals don't always decrease safety, using proper gases and decompression planning short surface intervals dont necessarily decrease bottom time on deep dives... I routinely due multiple 200+ ft dives with as little a 1.5 hour surface intervals, according to just about any dive planning software a surface interval of 1 hour will easily allow 200 ft dives 1 hr apart and the second dive the deco stops on 2 identical dives is usually SLIGHTLY shorter..

The recreational dive planner also gives padi's program a safety standard they can defend.. If every student is using a different computer they POSSIBLY could have to defend an instructor if a student gets bent folowing someone's computer model along iwth the computer designer. Law suits in the US are just to easy to file.

 

[Spectre]

Originally posted by Walter
Try to be fair. There's no reason to get upset over a rumor. If it later turns out to be true then would be the time to get upset.

It's not that I'm upset... more extremely concerned at the possibility.

"I've already spent much of my time since taking my OW course trying to learn the why's to what was taught, learning what I wasn't taught, and learning the "other side" to things that I was taught to be fact when in actuality it was propoganda based."

Good for you. I'm interested in hearing what was left out of your class that you believe should have been included. I'm also interested in what was presented as fact that turned out to be propaganda.

Let see... A couple key 'left outs'. First, altitude diving. I once had to explain to a certified diver why you can't do a night dive and then go skiing the next day. They knew about the no-fly limits, and they knew about special procedures for diving above 1000 ft, but they never drew the connection between the two and realized your at risk for DCI if you dive at sea level and then exceed 1000 ft after diving. Another one... the true risks to bouyant emergency ascents. A cold water diver dumping their weight belt is basically a death sentence when the belt has 20-35 lbs on it. A third [from AOW] the 'risks' of having emergency air @ 15 ft below the boat. If you are in a situation where you have two choices. You can make a normal ascent and probably have just enough air for your safety stop, or you can go for the anchor line, where the air is waiting for your safety stop, what do you do? If you take the extra time at depth to find the anchor line so you can get to the emergency air, you've just committed to _having_ to find the anchor line, if you don't find it, you now don't have enough air to safely reach the surface, where you did when you set off for the anchor line. Another would be no mention of self-sufficiency diving, yet no mention of taking into account both your buddy and yourself when it comes to gas supply planning. There are others but those are the ones that come right to mind.

As for 'propaganda', these are more subtle, and when I re-read my OW manual, I'll stumble across other things. However, I'm referring to things like "never re-enter the water if DCI is suspected". I take that as an opinion statement against in-water recompression. Not that in-water recompression is something that should be taught, but in certain circumstances it could be the difference between life and death and "Never" is a dangerous word. Another thing is PADI's opinions on artifact recovery [in wreck diving]. There are strong arguments for the removal of artifacts for the very reason they discourage it... so that others can enjoy it. Likewise the statements about disturbing archeologically significant placements of things... As a wreck degrades, everything moves anyway, and slowly but surely the artifacts get destroyed or lost forever.

Now I'm not condoning the above, I'm just purely stating that there are things that are debatable and controversial that PADI teaches as rules...

 

[seaangel]

I am not aware that SSI was not teaching dive tables. I am SSI certified as of one year and we were taught dive tables. We were told that someday it may become obsolete becauses of computers but that to have that knowledge was very important to be able to use a dive table. SSI and NASDS combined and the teaching materials are from NASDS mostly. I am going to assist with OW check outs in a couple of weeks and will be helping with the dive tables as needed there.

 

[Walter]

Cindy,

SSI teaches tables. SDI does not.

padiscubapro,

"Padi did back off the limits on compared to the Navy tables"

No, they did not. The NDL's were arrived at independently. As a result most are less than the US Navy NDL's, but the NDL for 130 ft is identical. Tables which were backed off are less than the US Navy NDL's at all depths. DCIEM also arrived at their limits independently, but their NDL's are all less than the US Navy's and less than the RDP for all depths except 40 ft.

"eliminted one of the very long tissue groups from their calculations (whick really only comes into play on very long shallow dives)"

They eliminated all compartments (tissue group is a misnomer) with half times over 60 minutes. You are incorrect about the longer compartments only coming into play on long shallow dives. The longer compartments' are obvious on long shallow dives, but they also play an important role in repetitive dives.

"Shorter surface intervals don't always decrease safety"

Face it, no tables are safe. You can get bent following any table. Some are safer than others. If you plan the same two dives with a short surface interval or a long surface interval you will have less of a chance of getting DCS with the longer surface interval. A shorter surface interval is less safe.

"The recreational dive planner also gives padi's program a safety standard they can defend"

They can defend the standard, possibly even successfully. It would be easier to successfully defend if the plantif didn't have a readily available table that was more conservative for the jury to compare with the RDP.

"Law suits in the US are just to easy to file."

I certainly agree with that.

 

[chuckrt]

I agree with seaangael, SSI has not stopped teaching dive tables. The dive tables are both in the book and on plastic cards to keep in your dive bag/log book. When taking Nitrox they are again retaught and new tables given, I did not have to pay extra for them as they were included in the course fees which were steep enough as it was.

chuckrt

 

[Liquid]

Originally posted by SubMariner
"
It's not. The only agency I know of at this point in time who actually did this was SSI. Is this "AOW Instructor" a PADI Instructor?

You'r wrong. I am an SSI instructor, and I have no knowledge of such things (and I am in costant conection with HQ).

 

[MikeS]

First off, in my opinion, for recreational diving, an air-integrated computer is much safer than with a table, SPG, Depth Gauge, and bottom timer. For occasional divers that dive on vacation several times a year, the odds of making a manual calculation error are much higher than the odds of a computer failure. Additionally, the computer provides other important real time information such as rate of ascent.

Your buddy’s computer provides redundancy; follow the more conservative of the two.
If either computer fails the dive is over, surface safely using the working computer.
If you want or need more redundancy, take a second computer along.

The only bad thing that I can see about not teaching dive tables in Basic Open Water courses is that it increases the entry level cost of diving, as computers are more expensive. I think that this will change and as air-integrated computer become cheaper than separate components and dive shops start equipping more rental equipment with computers.

For whatever reason there appears to be a totally illogical resistance to computers by people that learned and relied on the tables. I have not heard a single well stated logical argument against using computers. The typically story is “my cousin knew a guy who’s friend heard about someone who’s computer failed.”

I guess it’s human nature to fight innovation. The old drivers probably scoffed at the first speedometers and the new drivers that didn’t keep track of the RPMs and gear to tell how fast they were going.

Mike

 

[Paul168341]

Sorry guys, I haven't had time to read through all the replies but...
The last time I talked with Stush (Doviat, our Regional Rep.) at Member Forum we were assured that PADI is NOT getting rid of the tables. That rumor started when the new manuals were issued. Big James is correct, PADI received numerous complaints from people who wanted help with their tables when out diving and didn't want to drag the whole book with them. Also, by removing the RDP explanations from the manual, it offered the students more flexibility when learning them the first time around. Also, it leaves more room in the manual for other aspects of diving, like adverts for PADI continuing ed. courses.

 

[Spectre]

Originally posted by Paul168341
The last time I talked with Stush (Doviat, our Regional Rep.) at Member Forum we were assured that PADI is NOT getting rid of the tables. That rumor started when the new manuals were issued.

Very good to hear. Thanks Paul!

 

[diverdown50401]

PADI has been in business since 1966 and has always used dive tables and always will use dive tables. So has the US Navy which started the whole dive table principle. Batteries in Computers can go dead. It happened to a guy I was diving with in Cancun last year. The dive center did not have replacements my friend did not have a dive table with him luckily I did. We returned to the US without any physical or physiological problems. The day Dive tables are discontinued is the day I stop diving!!!!