SaltyWombat
Contributor
Does GUE have a standard for GF? I don't recall learning about that in Fundamentals.
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20/85.Does GUE have a standard for GF? I don't recall learning about that in Fundamentals.
Should ask Trace Malin how ratio deco went for him
Because GFs (esp the low) don't really apply to no deco diving. In T1 you'll be using 20/85 in decoplanner.Does GUE have a standard for GF? I don't recall learning about that in Fundamentals.
After writing an article on deep stops in decompression diving, I attempted to do the same for recreational diving. In my research, I contacted GUE headquarters for an explanation of the theory behind Min Deco, and I got an official explanation. From reading many threads over the years, I suspect the official explanation will be news to many GUE divers.Wasn't a topic of discussion when I passed fundies many years ago. Deco Planner is set to 20/85. Up to you to decide.
We were taught to ascend to 50% of current depth at 30ft/minute. From that depth it's 10ft/minute to the surface. Would love to see the current literature for Fundamentals and see how it has changed since I completed the course nearly 10 years ago.
After writing an article on deep stops in decompression diving, I attempted to do the same for recreational diving. In my research, I contacted GUE headquarters for an explanation of the theory behind Min Deco, and I got an official explanation. From reading many threads over the years, I suspect the official explanation will be news to many GUE divers.
Here are some key facts about it.
- It has nothing to do with GFs and the changing thinking on deep stops.
- It has nothing to do with deep stops at all, whether in NDL or decompression diving.
- The primary reason for it as related to decompression theory is a belief that the ascent rate should be slower as you get near the surface. That is the only aspect of this related to decompression theory.
- Halfway to the surface was chosen because anyone should be capable of the math required to compute half.
- The stops from halfway to the surface have two purposes:
- Slows the ascent, in accordance to the theory mentioned above.
- It mimics the decompression ascent, thereby providing a consistent standard procedure for ascents for all dives.
I am familiar with this, and it is interesting. There are two studies conducted 15-20 years ago regarding deep stops on recreational dives, and both are considered to be flawed. Partly because of that, DAN America's does not recommend deep stops for NDL dives. Despite that, DAN Europe does recommend deep stops, based on those two studies that are considered to be flawed.Hi John, Mark Powell in Min-Deco quotes a study (I believe it was by DAN) where they tested half stops in recreational diving and how they resulted in better bubble scores than those who were extending one shallow stops that most computers would generate. I personally reached out to Mark Powell about these half stops. Here is the conversation:
Me: Greeting Mark, quick question. I understand your earlier version of Deco for Divers that doing half stop in recreational diving profiles (100 ft and shallower) can be beneficial. With Spisni study on deep stops and US Navy study, do you still regard it to be a good decompression practice? It would require a GF lo to be 5. Thanks.
Mark Powell: Hi Aziz, those studies were not on no-stop dives so i wouldnt say they were relevant. I think the DAN study is still relevant for no stop dives so I would still do them on no stop dives.
The man is really high up in TDI food chain and as far removed from DIR as they come.
I did not mention this before, but Mark is absolutely correct in saying that there is a difference between decompression dives and no-stop dives. If there is anything I learned in my research, it is that there very much is such a difference, with a small gray area in between.Me: Greeting Mark, quick question. I understand your earlier version of Deco for Divers that doing half stop in recreational diving profiles (100 ft and shallower) can be beneficial. With Spisni study on deep stops and US Navy study, do you still regard it to be a good decompression practice? It would require a GF lo to be 5. Thanks.
Mark Powell: Hi Aziz, those studies were not on no-stop dives so i wouldnt say they were relevant. I think the DAN study is still relevant for no stop dives so I would still do them on no stop dives.