GF LO

[JonG1]

Just wondering would you have a link for this?
Regards

Cathal

I think it was Doolette tbh published in in depth I'll see if I can link it, but might already be in boulder John's post above

 

[JonG1]

Gradient Factors in a Post-Deep Stops World.

 

[boulderjohn]

I think it was Doolette tbh published in in depth I'll see if I can link it, but might already be in boulder John's post above

Yes, it was Doolette, not Pollock. But Pollock is in the same ballpark as Mitchell and Doolette. Here is a quote from a presentation he made that I included in my article:

“No deep stops! By slowing down deep, all you are doing is adding more time that you’re on-gassing into your slow and intermediate tissues that aren’t saturated. So deep stops have not been shown through any credible research to be in your best interest."​

 

[nadwidny]

50/75. I would go a bit higher even (60), but even getting buddies use 50 has been a long long term project. There is some serious inertia at 20 (GUE) and 30 (Shearwater default)

Hahaha!! I think I resemble that remark!! 50/80 now. I could do 60.

It's been a bit of a process from the 20/95 days.

 

[rjack321]

Hahaha!! I think I resemble that remark!! 50/80 now. I could do 60.

It's been a bit of a process from the 20/95 days.

20/95 is from a bygone era

 

[cathal]

Gradient Factors in a Post-Deep Stops World.

Thanks for that link, an interesting article from a very well qualified diver in this area!!

 

[macado]

I posted a similar response last year in another thread. My standard disclaimer has always been what works for me may very well bend someone else so your mileage may vary.

50/85 for decompression dives has served me well for last 6+ years so I haven't really had a reason to change. Before that I ran 40-45/80 so not a huge change.

If I feel there were other factors during the dive (working hard, cold, tired, not feeling great), I will pad my last GF-Hi to ~70-80 but otherwise I always feel comfortable getting out of water with 50/85.

My datasets been two dives a day in the 150-240ft range (45m-73m) in 39-42f (~4c) water. Runtimes vary from 80-120 minutes with minimum 90-120 minute surface interval or one longer 2.5-3+ hour dive in the 250-300ft range. I realize this is an arbitrary metric but I won't do more than one dive a day if it's in the 240ft+ range.

I'm young (late-30s) but not in the greatest athletic shape (I like beer too much) but I have always felt great with these profiles. Never felt overly tired or run down, never had any sort of muscle aches or 'niggles'. I've never had a DCS hit or any symptoms but I recognize that I'm only a dive away from changing that so I don't mind bumping down my GF-Hi given the opportunity. Your mileage may vary.

 

[kensuf]

50/80 or 50/85, depending on the duration of deco. Shorter deco, I'll surface when I hit a lower surfacing gradient factor (i.e. if my computer says 2 minutes of total deco for a dive at Ginnie, I'll stick around for 5).

 

[rsingler]

50/80 or 50/85, depending on the duration of deco. Shorter deco, I'll surface when I hit a lower surfacing gradient factor (i.e. if my computer says 2 minutes of total deco for a dive at Ginnie, I'll stick around for 5).

And generally, your GF99 will decline about 2% per min at 10 feet, so I read your comment as saying you actually surface at something like 74-79 with those GFs.

 

[kensuf]

no, you misunderstand.

If I have a 3 hour deco obligation, such as my last dive at the nest 2 weeks ago, I'll be happy to surface with a GF of 85.

If I have a 2 minute deco obligation, I'll stick round until my GF is lower.