forum.heinrichsweikamp.com

Today I did a very long and shallow dive.
The OSTC3 with newest firmware 2.97 showed me 110 minutes - the logbook on the computer as well.

My Buddies had 120 minutes on their computer.

Well during this long dive we almost surfaces to -0.5 meter - often (you know, this is where the catfishes are in freshwater).

Now comes the strange thing: after download with subsurface the dive time in the software is also shown with 120 minutes - so other than in the logbook.

Well I think not a real problem ?!?

Hmmm, maybe Subsurface compoutes the divetime by Dive-End-Time minus Dive-Start-Time. The OSTC itself runs a kind of stopwatch which is paused when you come very shallow (the treshold is somewhere around a meter, have to look into the code for the exact value...) as it thinks you are going to surface.
The dive-end-depth needs to be below 0 meters with some safety margin as elswise if the surface pressure changes a bit while you are diving, the OSTC will not be able to detect the end of the dive. But this hasn't changed in V2.97, it has been handled this way since ever.

I agree that subsurface (and other dive log programs like Diving Log) is showing the duration of the profile recording. OSTC always stops it's internal dive time counter when above 1m of depth. Profile recoding continues, of course. I'm quite sure that's the cause of the difference. We haven't touched this behaviour since years and I have no plans to ever change this.

regards,
Matthias