GF & Deep Stops

[Bago]

Hi, this is my first post.

I have just bought my new OSTC MK2 and dived with it last sunday for the first time.

I dived to 67m with OC mode without GF.

The OSTC MK2 presented no Deep Stops, is it a matter of no GF set up ?

Wich is the best setting to have deep stops ?

Thank you, your computer is awesome !!!

[dmainou]

From the MK2 website:

http://www.heinrichsweikamp.com/en/ostc_mk2/

What this OSTC Mk.2 dive computer is not:
Competition for cheap mass products for the occasional diver.

What this OSTC Mk.2 dive computer is:
An experimental platform for all experienced divers who are interested in the theory of diving and who value maximum transparency and individual adaptabily .

you need to understand what the computer is doing even if you don't know how to program.

Then you can get the computer to give you the deco profile that YOU want.

buy this book and read it:

http://www.dive-tech.co.uk/deco%20for%20divers.htm

It is meant for divers rather than mathematicians so I can guarantee that you will enjoy it.

Then read this.

http://www.decompression.org/baker/home.htm

# username: downloadfiles

# password: decompression1

Especially "undestanding M values" and "clearing up the confussion about deep stops"

It is an FTP so you'll need the details above to surf

The big picture is also sumarised in here.

http://www.rebreatherworld.com/general- ... mmies.html


Hope it helps.

D

[Bago]

Thx D

Anyway My question was a prelude to ask why we can't modify GF over 90 and under 30 ...

I will read out your book and maybe I will find out

Regards

[heinrichsweikamp]

Hello,

If you not sure what gradient factors are please start with the default values. They offer enough safety and are tested in the field intensively for the most standard dives (e.g. 60m with a deco gas). Aggressive settings like GF_high=100 can be used in special environments like caves but require a deeper understanding and a lot experience in decompression dives.

regards,
Matthias

[sailor]

Hi Bago,

i agree to the previous answers.
To give you a rough and brief idea here some more information.

In order to generate deep stops with the MK2 you need to activate GF.
The lower you set the first value the deeper the first stop is.
The lower you set the second value the longer the shallow stops are.

If you like very deep first stops you can select the first value as low as 5 but you should not set it bigger then 30.
The first value set to 30 doesn't really generate deep stops.

The second value shouldn't be set higher then 90. To generate longer shallow stops you may choose 85 or 80.

So a good GF-setting to start with is 20/85.
For deeper first stops use GF 10/85 or 5/85.
For longer shallow stops with a more shallow first stop you may choose 25/80 or 30/75.

So the first value should be set to 5 - 30, the second value should be set to 75 - 90.

To check different profiles you may use the simulator or any GF-based desktop-software like V-planner and so on.

Before using GF-settings read some more of the previously linked information.

Be safe and know what you are doing, Reiner

[Bago]

Thank you all... your answers tell me I landed in the right place !

In fact dive OC no GF and OC with GF set to 30/90 gives you the same deco
profile and no deep first stops.

Sunday I was diving with several friends (6) with GF standard setting 30/90 we noticed no big difference and no stops at deep.

Anyway I will surely read and study the OSTC, the book and links...

Thanks again, Bago.

[dmainou]

Bago Wrote:
-------------------------------------------------------
> Thank you all... your answers tell me I landed in
> the right place !
>
> In fact dive OC no GF and OC with GF set to 30/90
> gives you the same deco
> profile and no deep first stops.
>
> Sunday I was diving with several friends (6) with
> GF standard setting 30/90 we noticed no big
> difference and no stops at deep.
>
> Anyway I will surely read and study the OSTC, the
> book and links...
>
> Thanks again, Bago.

Hi Bago,

That is not accurate at all. The GF completely modifies the approach to the M Value.

Maybe you are simply modelling too shallow or too little bottom time. If you are attempting 3 minutes at 40 it is likely that most algorythms will tell you that no stops are required. However that doesn't mean that they arrived to the conclusion in the same way.

It also doesn't mean that you don't need to do any stops but decompression theory is is a matter to discuss elsewhere.

Try doing a simulation with a deeper and longer bottom time. You'll see the difference.

As per my first post, PLEASE do not play with the settings if you do not understand what you are doing. This computer does let you in command. Therefore, it is very important that you understand what you are doing.

Enjoy the book.

D

[Bago]

Yes You are right since it was the first dive we made with OSTC we planned really short Bottom time ... I will try the simulator and check but I agree

[Bago]

D
Your user & psw for [www.decompression.org] does not work
Do you have new ones or do you know why ?

[dmainou]

Bago Wrote:
-------------------------------------------------------
> D
> Your user & psw for does not work
> Do you have new ones or do you know why ?


Click on the ftp link and use the username and password previously provided.

They are revamping the website so not everything works.

http://www.decompression.org/maiken/VPM ... ations.htm

Once you are in go to Baker's folder. There is a lot more info but it is likely to be of little use to you until you understand a bit more. Also some theories differ to the theory behind the OSTC. So unless you wish to change to a different computer... By all means learn about the other theories but I would start with Mr Haldane > Workman > Buhlman > Baker's Gradient Factors.

The concepts behind the first three are very well covered on the "deco for divers" book. (However there is little to no math on the book). Baker's papers are on the FTP.

D

[dmainou]

The two articles you are looking for is:

"Understanding M-Values.pdf"

Then read

"Deep Stops.pdf"

However if you read this first you are really starting by the end.

D

[Iain]

Hello,

I just tried reading the documents at decompression.org but the user name and password did not appear to be working. Have these changed?

Iain.

[Touchwood]

It worked for me using FileZilla as an ftp client. Are you attempting to connect directly from your browser? Internet Explorer is rubbish for this.

[wrobell]

i believe you can find the same documents at

[dmainou]

I just tried.

Everything is there and password works. Firefox over Ubuntu Linux. straight through.


D