Gradient Factors - What is Everyone Using?

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UCFKnightDiver

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I'm interested in what gradient factor settings everyone is running and why? Does the type of dive you're doing affect your settings (e.g., cold vs. warm water, technical vs. recreational, clear vs. silty, other)? I've heard everyone is all over the map with regard to the settings they are using and I'm curious to hear if there's any sort of consensus.

I've been reading some of the past threads regarding gradient factors and decompression theory but didn't see this aspect specifically addressed, though admittedly I didn't read back super far. However, some of the threads regarding the efficacy of deep stops have been super interesting.

One thing that came to mind while reading those threads is it would be super interesting for Shearwater for example to sponsor some deco research. Many people upload their dive profile and data to their cloud based app. It might be interesting to have a short survey people could fill out after their dive with questions related to how they felt post dive, if someone had skin bends, other DCS symptoms, etc. You may only get people that have issues filling out the surveys, but I wonder if you would see some strong correlations between certain gradient factor settings and problems with DCS or even just feeling lousy after your dive (sub clinical DCS maybe?).
 
I use 50/85 for "normal" diving and 50/70 for any situation where I feel I need to have added conservancy (multiple dives over multiple days, far from a chamber, working dives, not in best condition (dehydrated, tired, etc) and so forth)

Shearwater has done a lot of work helping out deco research over the years, however the ROI on any meaningful research will always be limited. Basically, DAN and various military organisations (NEDU etc) are the only ones really in a position to do a lot of research, aside from the occasional project where there is a (often tangential at best) link to recreational diving.
 
I use 50/85 for "normal" diving and 50/70 for any situation where I feel I need to have added conservancy (multiple dives over multiple days, far from a chamber, working dives, not in best condition (dehydrated, tired, etc) and so forth)
Same ^
 
I used 50/90 for recreational dives and 50/80 or 50/85 for most of my tech dives. I’ve been out of the water for a while now so I’d work my way back to those values and probably start with 50/80 for rec dives and 50/75 for tech dives.
 
30/75 for cave diving (Apprentice level, nothing huge). I adopted the setting from my initial instructor, who was in his late 60s and planned very conservatively.

I use 50/75 for Lake Michigan wrecks because those dives are less physically demanding and typically shorter due to low bottom temps.
 
30/75 for cave diving (Apprentice level, nothing huge). I adopted the setting from my initial instructor, who was in his late 60s and planned very conservatively.

I use 50/75 for Lake Michigan wrecks because those dives are less physically demanding and typically shorter due to low bottom temps.
There is a problem with the use of the word "conservative" in this context. The word became popular with algorithms that used the word "conservative" for settings that created a deeper first stop, with the implication that staying farther away from the M-value line was safer. Stopping deeper on the ascent was believed to be safer.

Current thinking has moved away from that, with the realization that when doing stops deeper, you are adding nitrogen to the slower tissues, gas that must be eliminated later with longer shallow stops. Research indicated that deeper stops are not in themselves safer.

People associate the word conservative with safer, but if by conservative you mean adding more deep water time to your profile, you are likely not making your dive safer.

Here is some reading on this.
 
There is a problem with the use of the word "conservative" in this context. The word became popular with algorithms that used the word "conservative" for settings that created a deeper first stop, with the implication that staying farther away from the M-value line was safer. Stopping deeper on the ascent was believed to be safer.

Current thinking has moved away from that, with the realization that when doing stops deeper, you are adding nitrogen to the slower tissues, gas that must be eliminated later with longer shallow stops. Research indicated that deeper stops are not in themselves safer.

People associate the word conservative with safer, but if by conservative you mean adding more deep water time to your profile, you are likely not making your dive safer.

Here is some reading on this.

I use 70/85. I use it because Prof. Doolette seems to like it.

Thanks to John and his article, I learned a lot about the deep stops topic. His reference material at the bottom of his article was interesting to read.

Doolette's article:
Gradient Factors in a Post-Deep Stops World

John's article:
Evolving Thought on Deep Decompression Stops

cheers,
m²V2
PS: I am a faux tech diver with a Tech 40 cert. This stuff is interesting, but my life does not depend on it for the type of diving I do. Follow my GF factor setting at your own peril!
 
Using 50/85 on most dives.
Maybe for 60 metres plus, or in cold water long dives could use a more conservative approach (75 on GF Hi). In fact it seems to not have a exact number, jus picking a level where you feel confortable.
 
https://www.shearwater.com/products/peregrine/

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