Info Why are tables not taught in OW classes anymore?

[tursiops]

Hi @Nick_Radov

The DSAT (PADI) RDP and the DSAT computer decompression algorithm were specifically designed for repetitive dives in recreational divers. Sorry, I can only find the abstract, @dmaziuk may have a link for the entire publication that came from Rubicon

View attachment 771572

The report is available at DSAT_1994_unsecured_opt.pdf

 

[lowwall]

The key sentence is the last. He says there are two conditions for successful revenge. The first is that you don't get caught. The second, explained in challenging language at the end, is that you must make sure the victim knows the reason for the revenge. In the story, he never tells his victim why he is killing him, meaning the act does not meet his own definition of revenge. No motive is ever given anywhere, but it is implied. Fortunato, the victim, has been fortunate in his life, and the speaker has fallen on hard times. Fortunato is a blameless scapegoat for the speaker's misfortunes. He has done nothing to merit execution, which is why he does not understand why he is being killed. The trip through the catacombs is described as if it were a religious ceremony taking place in a cathedral. Their speech is liturgical in nature. It ends with Fortunato's arms chained to the wall at the end of the hallway, like a crucifix.

Ah, I see. It does add an entire new layer. But the genius is that it works so well as a pure horror story. I wonder what percentage of readers at the time caught the deeper theme given that contemporary readers were so well versed in biblical imagery and allusions.

Do we get an award for the greatest distance travelled from the subject of the original post?

 

[tursiops]

Do we get an award for the greatest distance travelled from the subject of the original post?

Yes, but no less interesting!

 

[dmaziuk]

This interminable debate about whether tables should be taught in OW courses largely misses the point. The real (and low) risks of DCS in open water diving largely come from bubble mechanics and multiple repetitive dives, particularly in combination with a circulatory system shunt such as a PFO.
None of the deco algorithms in common use today model those factors accurately. Bühlmann ZHL-16C doesn't even try. VPM-B and RGBM sort of try, but seem to have missed the mark, or at least empirically they don't produce better results.

The purpose of a decompression algorithm is to get the diver out of the water not bent on X out Y dives. That is "the point", "the mark", and "the better result". Not them inaudible echoes of the shadows of invisible bubbles in some part of physiology that may or may not exist in a specific individual diver.

That is explained in the DSAT report to which I do not have a link: I have a pdf downloaded from Rubicon back when. I am not going to attach it here because its copyright owners never gave me explicit permission to redistribute it, so I'm not doing it (but will be happy to let The Mod Squad figure it out -- @Akimbo: how do you upload something for inclusion in SB Download Library? -- posted instructions are for KnowledgeBase, not for Library).

 

[lowwall]

The purpose of a decompression algorithm is to get the diver out of the water not bent on X out Y dives. That is "the point", "the mark", and "the better result". Not them inaudible echoes of the shadows of invisible bubbles in some part of physiology that may or may not exist in a specific individual diver.

How dare you look at the forest instead of the trees.

 

[scubadada]

The purpose of a decompression algorithm is to get the diver out of the water not bent on X out Y dives. That is "the point", "the mark", and "the better result". Not them inaudible echoes of the shadows of invisible bubbles in some part of physiology that may or may not exist in a specific individual diver.

That is explained in the DSAT report to which I do not have a link: I have a pdf downloaded from Rubicon back when. I am not going to attach it here because its copyright owners never gave me explicit permission to redistribute it, so I'm not doing it (but will be happy to let The Mod Squad figure it out -- @Akimbo: how do you upload something for inclusion in SB Download Library? -- posted instructions are for KnowledgeBase, not for Library).

Thanks to @tursiops for the link, it can be downloaded and saved as a PDF, good reading

 

[Nick_Radov]

Hi @Nick_Radov

The DSAT (PADI) RDP and the DSAT computer decompression algorithm were specifically designed for repetitive dives in recreational divers. Sorry, I can only find the abstract, @dmaziuk may have a link for the entire publication that came from Rubicon

View attachment 771572

I am well aware of how DSAT tables and computer algorithms were designed. My point is that they haven't truly been validated for long sequences of multiple repetitive dives. That is where DSAT and all other tables and computers increasingly diverge from reality.

 

[tursiops]

My point is that they haven't truly been validated for long sequences of multiple repetitive dives.

You don't think that almost 40 years of successful use represents validation?

 

[Bigbella]

This interminable debate about whether tables should be taught in OW courses largely misses the point.

The point that you seem to be missing, is that directional selection toward the dumbing down of educational materials across the board, whether it's toward some Quixotic notion of "equity" where a correct mathematical answer is no longer even necessary; or whether it's some other meaningless California new-age word soup, doesn't really matter.

A friend who just retired from teaching college zoölogy, marine biology and ecology, mentioned that it couldn't happen sooner. He had gone from posing essay questions and encouraging some critical thought on various topics to just short answers -- "fill in the blank;" and, finally to Scantrons and multiple choice, because his administration, not he, demanded that -- along with a message that he had received from on-high, that many of his students were no longer capable of dealing with those materials that he had so successfully taught for over thirty years.

When I worked dive boats years ago, had some computer failed (and they frequently did, early on, being notorious for flooding), it was not uncommon to see divers just pull out their faded, often cracked dive tables from a bag; swear a bit, and piece together a profile with a grease pencil.

More recently, that same failure, unless redundant electronic equipment was also carried along, simply meant a long and expensive dry boat ride in the absence of tables; and contrary to many threads on SB, friends still in that industry, claim that only very few divers, less than five percent or so, carry more than the bare minimum -- and a couple of the older guys, who can actually still drive stick and ably light a fire, have taken to teach or even re-teach tables, in the event of an equipment failure . . .

 

[azstinger11]

The point that you are missing, is the directional selection toward the dumbing down of educational materials across the board, whether it's toward some Quixotic notion of "equity" where a correct mathematical answer is no longer even necessary; or whether it's some other meaningless California word soup, doesn't really matter.

A friend who just retired from teaching college zoölogy, marine biology and ecology, mentioned that it couldn't happen sooner. He had gone from posing essay questions and encoraging some critical thought to short answers; and, finally to Scantrons and multiple choice, because his administration, not he, demanded that, along with a message that he received from on-high, that many of his students were no longer capable of dealing with those materials that he had so successfully taught for over thirty years.

When I worked dive boats years ago, had some computer failed (and they frequently did, early on; notorious for flooding), it was not uncommon to just see divers pull out their faded, often cracked dive tables from a bag; swear a bit, and piece together a profile with a grease pencil.

More recently, that same failure, unless redundant electronic equipment was carried along, simply meant a long and expensive dry boat ride in the absence of tables; and contrary to many threads on SB, friends still in that industry, claim that very few divers, less than five percent, carry more than the bare minimum -- and a couple of the older guys, have even taken to teach or even re-teach tables, in the event of an equipment failure . . .

Guess i'm weird that I keep a small laminated NOAA air card in my dive bag and have the NOAA air and nitrox table PDFs on my phone. Also usually have a old AF zoop that is set to gauge mode that I can use for basic info. That being said if I'm diving CCR and computers go wonky in pre-dive or during a dive i'm staying dry afterwards.