Discrepancy with depth, time and sac

Discussions about Diving Log 6.0 - questions and hints
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Madocks
Posts: 1
Joined: Mon Oct 18, 2021 22:05

Discrepancy with depth, time and sac

Post by Madocks »

I am having discrepancies with my suunto software vs diving logs. The logs are imported from suunto so I am classing suunto as the master data.

Example 1
Suunto log - 39:31 min dive, average depth 13.6m, sac 21.2
DL6 log - 39 min dive, average depth 13.48, sac 21.82

Example 2
Suunto log - 36:11 min dive, average depth 18.2m, sac 19.6
DL6 log - 36 min dive, average depth 18.07m, sac 20.52

Example 3
Suunto log - 26:51 min dive, average depth 20.5m, sac 24.1
DL6 log - 26 min dive, average depth 20.2m, sac 26.76

It appears that DL6 is taking the data, and changing it, rounding the time to the nearest minute, altering my average depth and then calculating incorrect sac?
divinglog
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Re: Discrepancy with depth, time and sac

Post by divinglog »

Hello

The dive time is imported as it is stored in the Suunto database (with seconds), but it is rounded to full minutes when shown in the logbook window in Diving Log, except for free (apnoe) dives. For scuba dives which last an hour and more, the seconds are not really relevant. The dive time header value is not used for SAC calculation anyways, the time is calculated from the profile, with full decimal precision for every input value.

Average depth is not imported, it is calculated from the dive profile, too. Shallow samples (< 0.5 meter) are ignored in the average depth calculation, because you're on the surface at this time. Those samples are also ignored for SAC calculation, because you're breathing normal air at the surface and not gas from the tank.

Other applications may do things differently, so it is normal that you see small differences in calculated data. Data that is imported is not altered.

Kind regards,
Sven
divinglog
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Re: Discrepancy with depth, time and sac

Post by divinglog »

Just a clarification: Diving Log rounds the dive time correctly, so 26:51 will be shown as 27 min and 26:25 as 26 min dive. For all calculations like statistics and SAC the exact time will be used, so the rounding does not influence anything. Showing seconds for scuba dives simulates a precision that does not make sense. Your car also does not show decimal values for speed, for example.
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