Rising GF99 after surfacing???

[rsingler]

I agree with you, @scubadada
The new graph features are very nice. And now, my end-dive recorded GF seems to match the max on the graph!
How nice it is to have a company that listens to its divers!

But I confess, I'm trying to learn the utility of having SurGF in the display, other than curiosity about how high it got during the dive.
Since I was finally able to get my phone (although not my laptop) to upload dives to Subsurface, I can now evaluate SurGF after I transfer the dives via my account to the laptop. Perhaps Shearwater will get around to this request too, though they have a lot on their plate with the new Tern.
But what should I be looking for in comparing SurGF with my GF99? I thought about riding some GF99 in a continuous ascent, instead of making stops on my next deco dive. If I felt okay after surfacing, it would be interesting to look at the convergence of SurGF with my surfacing GF99, but what other information would that give me?

Again, a shout out to Shearwater!!!

 

[rsingler]

To summarize what was going on here, for certain calculations (dive duration, for example), Shearwater defaults to 0 at any depth above 3.1feet, and calls that "surfacing". Your arm may be hanging in the water as you wait for the boat, and they didn't want the dive to continue at 1.7 feet for twenty minutes as you floated.
Although the dive "ended", the computer continued to make calculations. And as we've seen, GF99 rises precipitously in the last few feet. That continued rise was lost when the change was made to stop graphing after the system called "surface" at 2.9 feet.
Now that the graph has been "unclamped" to allow visualization of the continued calculations, we can see what was happening in the last three feet. And perhaps there is some brief computational lag that allows displayed GF99 to rise briefly after the computer is at the true surface.
But most important for me, Shearwater has changed how it tabulates the surfacing GF99 of the dive: instead of registering the GF99 that was displayed at the moment the computer called "surfacing" (at 2.9 feet), it continues to watch the GF99, and tabulates the maximum that is displayed over the next couple of minutes.
That eliminates the discrepancy between what we can clearly see is a higher GF99 on the graph, compared with the GF99 that the system erroneously called end-dive GF while you were still on your way up at 2 feet.
Because of the rapid rise in GF99 in the last few feet, we had a discrepancy between the tabulated dive value and what one could clearly see on the graph, that has now been eliminated.
I can now quickly go through the dive summary and compare end-dive GF's with how I felt, as I personally assess my chosen gradient factors for deco.

 

[batdiver_82]

yes, but I can still see quite a significant discrepancy when comparing logged end-dive-GF (SW-cloud) vs. the last Surf-GF-value (Subsurface) - that´s why i´m not shure whether I can trust end-dive-gf.

 

[rsingler]

Screenshots?

 

[batdiver_82]

 

[rsingler]

Interesting...
We seem to have differing results:

I would suggest that our difference is that in your second graph, your cursor is not at the max GF moment, because the summary data is very similar between SS and Shearwater.
As you show in both your insets, the summary for your dives is within 1% of what Subsurface lists.

 

[batdiver_82]

yes, I have updated the sw-cloud-desktop; for some reason SS clamps my dive-data automatically. yes the end-dive gf (SW) and the last logged gf (SS) ist pretty much the same, but there is a big difference to the last logged surfGF (SS). But you are right, subsurface also automatically clamps the dive - don´t know how to change this...

another dive:

 

[rsingler]

To unclamp the graph, start on the Graph Display and click Settings

On the settings display, click the Clamp Duration button so it's not colored in...

To return to your graph, click the little left arrow

Now you can see all the calculations after you reached the surface:

 

[batdiver_82]

SW-Graphs are unclamped - my dive ends 3min after surfacing, maybe I will change it to 10 min....

 

[batdiver_82]

I´ve got one last dive

end-dive-gf Shearwater-cloud says: GF=17
Subsurface: GF=37

don't know what's wrong...

edit: I've sent the file to shearwater - let's see what they say...