Diving with gradient factors for a new recreational diver

[boulderjohn]

https://www.taucherpedia.info/images/de/e/ee/DECO2000_Vorderseite.png It is directly into your face that as soon as you exceed ndl, 3 meter stops added and longer 6meters and so on. There is no confusion on what to do, and absolutely identical to the behavior of a dive computer.

So all the divers carry those tables around with them in case they accidently exceed NDLs, or do they memorize them?

 

[boulderjohn]

so they blamed the fast tissues and quoted one Richard Pyle who was doing deeper decompression stops and felt better afterwards.

In the famous "fish nerd" publication in which Pyle introduced the idea to the world, he actually credits the previous work of Yount (VPM) and Wienke (RGBM) for the rationale. Yes, Pyle made it most famous, but he did not claim credit for it.

It's possible that the people pushing the idea hardest were the people at WKPP (and later GUE and UTD). At the deep stops conference that first brought out the evidence that deep stops did not work as advertised, the WKPP people were there to say they did. When I was with UTD, deep stops were gospel, and they mocked deep stop practices that were not deep enough.

 

[tursiops]

In the famous "fish nerd" publication in which Pyle introduced the idea to the world, he actually credits the previous work of Yount (VPM) and Wienke (RGBM) for the rationale. Yes, Pyle made it most famous, but he did not claim credit for it.

It's possible that the people pushing the idea hardest were the people at WKPP (and later GUE and UTD). At the deep stops conference that first brought out the evidence that deep stops did not work as advertised, the WKPP people were there to say they did. When I was with UTD, deep stops were gospel, and they mocked deep stop practices that were not deep enough.

Here is the Pyle publication and a David Doolette publication In a "post-deep stops world."

 

[boulderjohn]

Here is the Pyle publication and a David Doolette publication In a "post-deep stops world."

The Doolette publication has influenced my diving and the diving of all my friends. Interestingly enough, it was published in the GUE blog. More interesting, the GUE blog soon after that published an article with a title that indicated that new evidence was supporting deep stops after all--but with nothing of the sort in the article itself.

Doolette's publication in the GUE blog very nicely mentioned my own publication, which came out shortly before that. My article cited a GUE article explaining how to do deep stops, but after I cited it, they changed it by adding a disclaimer saying it did not represent current thinking.

 

[Celt]

Knowing how much deco and following strict profiles is not enough to stop you getting bent if you don’t know your personal limits and tolerance. Long hard deco dives carried out over a number of weeks takes its toll on even the fittest of divers. Very important to know when to take a break. There’s a tiredness that you can feel.

 

[scubadada]

Furthermore if the 100/100 has been tested and verified to be "X risky" and 30/85 was never formally studied & verified at all, even the claim that it's "less risky" is technically questionable. Common sense suggests that is should be "less risky" and anecdotally it seems to be so, but strictly speaking we can only claim that is "should be no more risky".

Duration of exposure is certainly linked to risk. The longer the exposure, the greater the risk. The question is, what is the risk? Take a look at the probabilistic algorithm I linked above Diving with gradient factors for a new recreational diver

 

[doctormike]

Im not sure that’s really an accurate statement.

No commercially available models allow the diver to select their DCS risk in a discreet way.

Maybe we are just using different terminology.

The models allow for adjustments which will modify the maximal allowed overpressure on ascent. If there is one central theory of decompression, it is that clincial DCS is correlated with the degree of overpressure, not sure that's contoversial.

So while your actual DCS risk depends on a lot of variables that aren't accounted for in the model, changing things like GFs or conservatism factors will increase or decrease the DCS risk for a given diver on a given dive, right? Adjusting constants in the algorithm won't let you select your DCS risk quantitatively, but it will allow you to make it greater or lesser.

 

[J-Vo]

On the PDC usability and instruction subject,

My brother has been a dive master since 1996. He has been using the same Oceanic PDC he got during his OW for 25 years. A couple years ago it flooded while we were in Cozumel. I had brought a spare Oceanic that he used to complete the week of diving.

Sometime last year I get a call from him, he was at the LDS and asked "Do you know anything about Shearwater?" I recommended them and he came home with a nice new Peregrine for is upcoming trip to Cabo.

A couple days into his trip he calls me, "Hey this new computer is great, but I have a question. It says 'NDL' and there is a number. What does that mean?" He had never looked at anything on his old Oceanic but the bar graph to make sure it was never in the "Red".

Now my brother is an excellent open water diver and an amazing dive mister/guide. His buoyancy may even be better than mine with my Cave and Trimix certifications. As a dive master and potential future instructor, I don't think he is qualified to teach anyone about dive computers. He would however be a great at teaching the practical application of dive skills to beginners.

 

[tursiops]

He would however be a great at teaching the practical application of dive skills to beginners.

He probably ought to stick with this, and forget instructing. Is RTFM so hard?

 

[Dan]

He probably ought to stick with this, and forget instructing. Is RTFM so hard?

He doesn't need to RTFM. What's a brother for?

Seriously, TFM is very well written and easy to read. He needs to RTFM!