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<div class="moz-forward-container">On 08/01/2017 12:27, Robert
Helling wrote:<br>
<blockquote
cite="mid:59198479-AB6B-4B84-894C-120B65C3EABD@atdotde.de"
type="cite">
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Hi,
<div class=""><br class="">
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<blockquote type="cite" class="">
<div class="">On 07 Jan 2017, at 22:43, Rick Walsh <<a
moz-do-not-send="true"
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href="mailto:rickmwalsh@gmail.com"><a class="moz-txt-link-abbreviated" href="mailto:rickmwalsh@gmail.com">rickmwalsh@gmail.com</a></a>>
wrote:</div>
<br class="Apple-interchange-newline">
<div class=""><span style="font-family: Helvetica;
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-webkit-text-stroke-width: 0px; float: none; display:
inline !important;" class="">I'm interested in hearing
Robert's feedback on your suggestion, but would be
happy to implement it when I get a chance (and that's
been far too rarely lately) after 4.6 is out.</span><br
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<div class="">my concerns are pretty much the same: The planner
already has almost too many parameters to configure. Not
concentrating on the essentials has a real price in usability.</div>
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</div>
<div class="">So adding two more parameters (problem solving
time and emergency SAC or whatever you might call those) needs
to be justified by the benefit. I am not going to add those
for everybody just to please a single user. But if one can
make the case that it benefits most users (in the sense of
they care about the resulting information) then we should have
those. I have done some googling on „Rock bottom gas“ and
almost everybody has their own idea how to exactly calculate
that. But indeed, the two parameter model fits many. So it
might be something for 4.7. But I would love to have some more
user input.</div>
<div class=""><br class="">
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<div class="">Best</div>
<div class="">Robert</div>
</blockquote>
The rock-bottom approach is sensible in a recreational environment
because it provides an explicit framework to think seriously about
gas planning which few recreational divers do. I am not sure which
training agency(s) uses this concept. In a technical/cave
environment, most training agencies have their own ways of
teaching explicit gas planning, with most using rule of thirds or
rule of quarters. As indicated in the previous discussion, the
situation becomes very complex when using deco gases and one
wishes to use the rock-bottom concept (as well as additional
planning for regulator failure of a deco cylinder) and the example
calculation for a 60m dive in previous correspondence shows that
this approach soon becomes unproductive within the technical
diving context. I have been involved as a donor in two
recreational OOG events and, fortunately, the gas consumption did
not skyrocket. So rock-bottom pressure level is interesting to me,
but I myself use the proven rules of the training agency where I
got certified.<br>
Kind regards,<br>
willem<br>
<br>
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