Deep Stop

[Abyss79]

Hi everybody
thanks for the new firmaware there was sime nice add on.
Safety stop, graphic ascent ratio

Do you think will be a good idea to add a system for calculating deep stop (Pyle stop or similar).

I will appreciate them. Think about it!

Christian

[Bardass]

What do you think of GF ...

[swissdiving]

As Bardass says check out GF.

[Abyss79]

OK GF show me the % in case it will became grater then a certain value.
Deep stoop is a bit differente.
If the ascent between max depth and first deco stop is more than 10 meters you should stop for a couple of minute and so on until the distance between actual depth and safaty stop is less the 10 meters.

You can't do this with GF, or i'm missing something?

Thanks

[swissdiving]

Correct but Bühlmann does only allow an approximation of deepstops through GF.

[Bardass]

Abyss79 Wrote:
-------------------------------------------------------
> OK GF show me the % in case it will became grater
> then a certain value.
> Deep stoop is a bit differente.
> If the ascent between max depth and first deco
> stop is more than 10 meters you should stop for a
> couple of minute and so on until the distance
> between actual depth and safaty stop is less the
> 10 meters.
>
> You can't do this with GF, or i'm missing
> something?
>
> Thanks



why did you bought an ostc then ?

[swissdiving]

@Bardass
I am assuming you're adressing Abyss...

[Bardass]

swissdiving Wrote:
-------------------------------------------------------
> @Bardass
> I am assuming you're adressing Abyss...

no

[Abyss79]

I'm using Aladin computer and buhlmann table since I start diving, and I'm happy with it.

Deep stop is not something against buhlmann, but just a way to control the size of boulbe during ascending.

I will do deep stop also if computer doesn't say to do it.So why not include them as an option.
About me could be nice feature to have. But I can survive also without it.

[swissdiving]

@Bardass
I am not that fussed about deep stops. I do deep stops anyways. Besides I love the OSTC as it is.

@Abyss
Its not about whether to include deeps stops or not. Its about the Bühlmann algorithm which does not encompass them.

A different algorithm would have to be implemented (rgbm or if I am not mistaken VPM). HW has no intention of implementing those algorithms.

[wrobell]

Abyss79 Wrote:
-------------------------------------------------------
> I'm using Aladin computer and buhlmann table since
> I start diving, and I'm happy with it.
>
> Deep stop is not something against buhlmann, but
> just a way to control the size of boulbe during
> ascending.
>
> I will do deep stop also if computer doesn't say
> to do it.So why not include them as an option.
> About me could be nice feature to have. But I can
> survive also without it.

Please read the following

http://liquivision.com/docs/deepstops.pdf
http://www.ddplan.com/usage.htm

In short: gradient factors are better version of deep stops.

w

[Abyss79]

I read the articles,
so the best is to decrase the high GF.
What you use as GF low and hight?
Now I'm using 30% and 90%

I make same test and from a dive at 50m for 15 minutes deco start at 15m
If I put HGF to 75 it became 18m

Also in this way from 50m to 18m there is a lot of space and personally I prefer to stop between 30 and 35m for safaty.

[swissdiving]

@Abyss
Read this to understand more about GF:
Clearing Up The Confusion About "Deep Stops"

[sailor]

Hi Abyss,

for a deep stop try GF 5/80 or 10/80 ( alternativly 5/90 or 10/90 ).
The first GF value controls the deeper stops, the second value controls the shallow stops.
The smaller the first value the deeper the first stop.
The smaller the second value the longer the shallow stops.

Make sure to read and understand GF values with the already provided links.
Make sure to dive these values only after completly understanding them.
Diving the OSTC without understanding the customized GF values might be dangerous.

Reiner

[wrobell]

Abyss79 Wrote:
-------------------------------------------------------
> I read the articles,
> so the best is to decrase the high GF.
> What you use as GF low and hight?
> Now I'm using 30% and 90%
>
> I make same test and from a dive at 50m for 15
> minutes deco start at 15m
> If I put HGF to 75 it became 18m
>
> Also in this way from 50m to 18m there is a lot of
> space and personally I prefer to stop between 30
> and 35m for safaty.

YMMV, but if I understood the Baker's paper well (the PDF file linked
above), the 30m-35m deco stop is not giving you more safety - it might
be problematic on shallower stops - this is explained in the text of
the paper (page 3) with appropriate graph (Figure 2).

As others explained, lower GF Low value to have deeper stops.

Fortunately, OSTC has nice simulator builtin (well... two of them:)),
so I would encourage you to try at home.

w

[wrobell]

the following article provides some insight about deeper stops as well http://hhssoftware.com/v-planner/decomyths.html