Graph documentation [was: Re: Meaning of GF settings]

[Miika Turkia]

On Tue, Jan 8, 2013 at 9:49 PM, Pierre-Yves Chibon <pingou at pingoured.fr> wrote:
> On Tue, 2013-01-08 at 11:39 -0800, Linus Torvalds wrote:
>> On Tue, Jan 8, 2013 at 11:25 AM, Pierre-Yves Chibon <pingou at pingoured.fr> wrote:
>> >
>> > At least for beginners divers such as myself, it would be usefull as, for
>> > example, all my dives cross the ceiling at the end (which appears to be normal,
>> > but up to which point?)
>>
>> Seriously? That's definitely not normal. For a beginning diver, you
>> should seldom really see a deco ceiling at all, much less one where
>> your dive cross into it, unless you set some very conservative deco
>> settings.
>>
>> Willing to post your divelog? A single dive might do it, but because
>> the deco is calculated over the history of the last few days, it
>> should probably be at least one divetrip (up until the dive that shows
>> the behavior).
>
> Attached are the two first dives I did with my computer, the first dives
> of the trip as well.
> We did have a deco stop during the second dive (#9) but we 'only' did
> the safety stop 3min/3m during the first dive (#8)
>
>> Of course it may be that you just have a very permissive dive computer
>> and just ascend very early.
>
> I have a suunto vyper which was set at P1 (preference 1, more
> conservative than the default, less than P2). The divemaster on the
> second dive had the same computer set at P0 which was telling him that
> there was no need for a stop beside the usual 3min/3m.
>
> I used the default parameters btw (GFlow 30 and GFhigh 75)

I do also have Suuntos and it seems to be a norm that Subsurface gives
a ceiling when the Suunto (or two of them) did not. I even have one
ceiling with a Suunto Stinger that ends just about at the same time as
the dive even though the computer did not give deco during the dive.
And this was with 50/100 GF settings! It might well be that the RGBM
is too different to do straight comparisons or it might be there is
something wrong in the calculations...

miika