Fwd: Re: Dive Stats: "Average" depth lower than "Minimum" depth

[Rick Walsh]

---------- Forwarded message ----------
From: "Rick Walsh" <rickmwalsh at gmail.com>
Date: 30 May 2014 19:23
Subject: Re: Dive Stats: "Average" depth lower than "Minimum" depth
To: "Lutz Vieweg" <lvml at 5t9.de>
Cc:

Lutz,

On 30 May 2014 19:08, "Lutz Vieweg" <lvml at 5t9.de> wrote:
>
> Hi,
>
> after returning from a 3 weeks diving trip(*) I only found one minor
> issue to report that I just added to the bug tracker:
>
> https://trac.hohndel.org/ticket/521
> Dive Stats: "Average" depth lower than "Minimum" depth

I'm pretty sure 'minimum' is actually the minimum of all the maximum
depths. I.e. the deepest point of the shallowest dive. As you noted, the
'true' minimum of 0 is meaningless.

Average should be the actual average depth.

>
> In addition to the defect description: I wonder whether displaying
> a "Minimum depth" or an "Average Depth" is useful, at all, since all
> dives start and end usually at depth zero, and I don't see how e.g.
> another 5 minutes that one could or could not have spent at very
> shallow depths at the start of a dive would contribute useful
> information into an "average" calculation.
>
> IMHO, a completely different value would provide more useful
> information: Some figure on how long tissue compartments came
> close to their point of pressure gradient tolerance during the dive.
> That could give a better (still vague) indication on the overall
> DCS risks of a dive.
> And since Subsurface computes saturation models, already, such
> a figure should not be difficult to derive.
>
> Regards,
>
> Lutz Vieweg
>
> (*) I'm now spoilt for life with regards to Manta sightings.
>     Two consecutive dives with > 10 Mantas present the whole
>     time of the dive in Pulau Langkoi (south Komodo) leave
>     little room for improvements. ;-)
>

We're all a wee bit jealous
_______________________________________________
> subsurface mailing list
> subsurface at hohndel.org
> http://lists.hohndel.org/cgi-bin/mailman/listinfo/subsurface
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.hohndel.org/pipermail/subsurface/attachments/20140530/62d9b6cc/attachment.html>