What's your SurfGF and how does it compare to your (Rec) GFHi?

[Fastmarc]

Having gone a few dives with the Shearwater, I'm still observing my SurfGF with interest.
I'm running 45/95 and on the 1st dive over the weekend with a max depth of 91ft, I got to within 3 mins NDL and started slowly ascending waiting on my buddy. When I reached 50ft about 7 mins later I was now showing NDL 22mins however my SurfGF was still at 95. Interesting. NDL really gives you no idea of how close you are in terms of deco stress. Before having the ability to see SurfGF I would have thought I was very safe and could stay deeper longer air provided which I usually have. My dive buddy was a very experienced lady, so she had pleanty of air too, but 2 others did not, so the dive was just 38 mins.
Continued my normal slow ascent with a 5 mins safety stop recommended (adaptive mode), but I stayed just a little longer and ended with a surfacing GF of 66.

 

[dmaziuk]

When I reached 50ft about 7 mins later I was now showing NDL 22mins however my SurfGF was still at 95. Interesting. NDL really gives you no idea of how close you are in terms of deco stress.

You GF was still 95 because the model thought your tissue compartment leading at that point was slower than 7 minutes. You gotta get yourself some faster-reacting tissues if you want to attract younger girlfriends, that's all there's to it.

And if you find a formal definition of that "decompression stress" you speak of, please post a link.

 

[rsingler]

with a max depth of 91ft, I got to within 3 mins NDL and started slowly ascending waiting on my buddy. When I reached 50ft about 7 mins later I was now showing NDL 22mins however my SurfGF was still at 95.

A couple of questions -
Was that leisurely ascent due to reef contour, or a deliberately slow free ascent?
And after the discussions on this thread and the thread on slow final ascents, did your SurGF staying at 95 make sense after the fact?

Any chance you could post the Shearwater file for that dive? It would be interesting to look at GF99 vs SurGF during the ascent.

 

[Fastmarc]

You GF was still 95 because the model thought your tissue compartment leading at that point was slower than 7 minutes. You gotta get yourself some faster-reacting tissues if you want to attract younger girlfriends, that's all there's to it.

And if you find a formal definition of that "decompression stress" you speak of, please post a link.

Great, one more thing to keep those younger ladies out of my reach...

Here's the link... hang on, where did it go... it was just here...

 

[Fastmarc]

A couple of questions -
Was that leisurely ascent due to reef contour, or a deliberately slow free ascent?
And after the discussions on this thread and the thread on slow final ascents, did your SurGF staying at 95 make sense after the fact?

Any chance you could post the Shearwater file for that dive? It would be interesting to look at GF99 vs SurGF during the ascent.

It was a free ascent in open water. Just my normal ascent. The only delay was at the beginning as I was staying with my buddy while she did her photography. Normally I start getting shallower when I hit single digits.

I was trying to post the file, but it's not being accepted.

 

[Fastmarc]

Ok, here's a link to the file.

Box

 

[dmaziuk]

Here's the link... hang on, where did it go... it was just here...

You realise that you're looking at a self-fulfilling prophecy, so to speak, right? If you set your safety to GFHi95, that's the upper limit for your surfacing GF as long as you don't overstay the NDL. If you don't get anywhere near the NDL, it will be lower, but if you're close: 95's gonna be it.

 

[Fastmarc]

And after the discussions on this thread and the thread on slow final ascents, did your SurGF staying at 95 make sense after the fact?

Forgot to answer this.
Yes, it did. After reading these threads, prior to having access to SurfGF, it's what I thought I might see, so seeing it in relation to the NDL was interesting.

 

[Fastmarc]

You realise that you're looking at a self-fulfilling prophecy, so to speak, right? If you set your safety to GFHi95, that's the upper limit for your surfacing GF as long as you don't overstay the NDL. If you don't get anywhere near the NDL, it will be lower, but if you're close: 95's gonna be it.

Yeh man, I know.

 

[muzikbiz22]

If you set your safety to GFHi95, that's the upper limit for your surfacing GF as long as you don't overstay the NDL. If you don't get anywhere near the NDL, it will be lower, but if you're close: 95's gonna be it.

Thank you for explaining this in English/Layman's terms