forum.heinrichsweikamp.com

Hello everybody,

I was woundering if I ther is a CF where I can adjust the conservatism.
Because the no-deco bottom time sometimes is really short, often even shorter then the RDP-tables.

greetings
Maxime

Hello,

check Wiki regarding custom functions CF11 / CF12 and CF32 / CF33 but make sure you know what you are doing.
Playing with these values without knowing what they do might be very dangerous.
The OSTC will display a dead mans skull as a warning when these functions are set to a dangerous value.

Reiner

read this post

http://www.heinrichsweikamp.com/read.php?2,3638

But the thing is, you can't adjust CF11 & 12 unless you put them even more conservative.
If you go under 110 (CF11) or above 90 (CF12) then you receive a "skull" warning
So you can only put it more conservative

Hi,

you can use the OSTC with the "skull"-warning but you need to know what you are doing.
The warning makes you aware that the computer is set to less conservative then recommended.
Other computer might not warn you but they are as dangerous with a reduced conservatism as the OSTC.
Reduced conservartism is dangerous, with or without warning.


Reiner

Hi,

Thanks Reiner.
But I think it would be nice just to have a CF that you can adjust from -2 to 2 for adjusting the conservatism easily without having the skull warning (unless you go under 100%). Because with the standard Bühlmann you have a 12min no deco bottom time at 36m and now with the MK2 you only have 9min.I think it wou be nice just to be able to dive the standard Bühlmann without always having a warning and then if you want it more conservative that you can adjust it.

Maxime

maxime Wrote:
-------------------------------------------------------
> Hi,
>
> Thanks Reiner.
> But I think it would be nice just to have a CF
> that you can adjust from -2 to 2 for adjusting the
> conservatism easily without having the skull
> warning (unless you go under 100%). Because with
> the standard Bühlmann you have a 12min no deco
> bottom time at 36m and now with the MK2 you only
> have 9min.I think it wou be nice just to be able
> to dive the standard Bühlmann without always
> having a warning and then if you want it more
> conservative that you can adjust it.
>
> Maxime


You are kidding, right?

If you want a computer that gives you a +/-2 as the only options buy something else.

It is quite obvious that you failed to read this statement from the main screen of the OSTC website: The OSTC "is an experimental platform for all experienced divers who are interested in the theory of diving and who value maximum transparency and individual adaptability."

This computer does let you in full control of the algorithm.

If you know what you are doing you can get it as aggressive as you want. Now, don't expect the computer to endorse all your choices by not giving you any warning.

If you want plain buhlman just go OC-GF and set both to 100%. Before you do this, call DAN and get some insurance first.

Also, I spent some time modelling on the simulator. After 9 minutes it requires you to spend 1 minute at 3m. This is one third of the "safety stop" on the RDP so you are probably creating a storm on a glass of water.

BTW, who told you that the RDP has the same basis as Buhlman? If you want something even more aggressive use the original Navy tables or even easier don't use any tables at all.

D

That's not whar I meant to say D, I know the RDP tables are based on another model.
I was comparing the Buhlmann tables with the MK2.
I meant it would be nice to dive the normal bühlmann without having a warning and only have a warning if your CF11 is set under 100%.
When I do deep and long dives I always dive my profile more conservative then my computer indicates. Only when I do not to hard dives I like it to be a LITTLE bit more tolerant.
BTW: I did hundreds of dives diving the plain Bühlmann without any accidents or even the minest problems.

No need of attacking me for that question. Wasn't asking for a suicide function or something like that.

M

maxime Wrote:
-------------------------------------------------------
> That's not whar I meant to say D, I know the RDP
> tables are based on another model.
> I was comparing the Buhlmann tables with the MK2.
> I meant it would be nice to dive the normal
> bühlmann without having a warning and only have a
> warning if your CF11 is set under 100%.
> When I do deep and long dives I always dive my
> profile more conservative then my computer
> indicates. Only when I do not to hard dives I like
> it to be a LITTLE bit more tolerant.
> BTW: I did hundreds of dives diving the plain
> Bühlmann without any accidents or even the minest
> problems.
>
> No need of attacking me for that question. Wasn't
> asking for a suicide function or something like
> that.
>
> M

Sorry mate, Engrish is not my first language. Once I read it again it does read bit aggressive (which is not what I intended).

The table will hardly match the computer mostly because one is based on ZHL-B whilst the other will be ZHL-C. They should be close for a minut or two which is what you have observed.

Now, it is my understanding that Buhlmann suggested that it would be sensible to load be faster than the unloading and therefore why the default settings. You can remove that asymmetric loading but you'll have a scull. (you can pretend you are a pirate)

A huge benefit of the OSTC is that it WILL let you do those things. You don't have that benefit with most other computers.

If you wish to match the TDI decompression tables what you actually need to do is run it on GF 90/90

A further thing you can do is to download a copy of DecoPlanner or similar software and play with it and the OSTC simulator until you understand how the profile gets affected by what setting.

Once you have downloaded a modelling tool you can verify that the GF 90/90 proposed above does match the TDI deco table.

That also means that the NDL/Deco table you have been using is not plain Buhlmann but it is padded as well.

Have you used the OSTC in conjunction with any other PC? I used to have a N2ition 3 and they had basically the same NDL's. Then the obscure algorithm of the other would take over and they would be somewhat different but that is another story.

I hope this is a bit more clear.

D

Ok thanks!

It's more clear now. And yes, I've did some comparing with a Suunto Helo2 and a shearwater predator (but the last you can forget about, its more for CCR).
But my Helo2 does give me more NDL and brings me out of the water faster (I know that with the GF's you can "generate" deepstops)but my point is that the NDL is quite a bit longer.

Also this is why I bought the OSTC, it gives you the possebility to try some new things and to adjust it wherever you want.
I was only saying that the skull warning maybe could only be activated if you go below the 100%.
But thanks alot for the help guys!

M

maxime Wrote:
-------------------------------------------------------
> Ok thanks!
>
> It's more clear now. And yes, I've did some
> comparing with a Suunto Helo2 and a shearwater
> predator (but the last you can forget about, its
> more for CCR).
> But my Helo2 does give me more NDL and brings me
> out of the water faster (I know that with the GF's
> you can "generate" deepstops)but my point is that
> the NDL is quite a bit longer.
>
> Also this is why I bought the OSTC, it gives you
> the possebility to try some new things and to
> adjust it wherever you want.
> I was only saying that the skull warning maybe
> could only be activated if you go below the 100%.
> But thanks alot for the help guys!
>
> M

Hel02 is a bubbl implementation so the stops will be relatively different.

The shearwater runs the same algorithm as the OSTC (although different implementation) so a GF 30/80 should come very close yo the OSTC.

I actually dive with a lot of guys with predators and not much difference.

The asymmetric loading only seems to make a big difference for shallow dives and adds a minute or two to a deco dive so don't really see the point.

As I say to my friends. You can wait with me a minute or two more or you can wait sitting on the boat. Still you have to wait for me.

D

dmainou Wrote:
-------------------------------------------------------
> As I say to my friends. You can wait with me a
> minute or two more or you can wait sitting on the
> boat. Still you have to wait for me.
>
> D

Dmainou-- what I want to know is if you stock deco beer on the boat, 'cause if so, I think I know where I will be waiting....

honeybadger Wrote:
-------------------------------------------------------
> dmainou Wrote:
> --------------------------------------------------
> -----
> > As I say to my friends. You can wait with me a
> > minute or two more or you can wait sitting on
> the
> > boat. Still you have to wait for me.
> >
> > D
>
> Dmainou-- what I want to know is if you stock deco
> beer on the boat, 'cause if so, I think I know
> where I will be waiting....


We don't store any beer on the boat. It would be handy though . Then the beer and I can frizz together!

More seriously, lately I have been diving with a shop focused only on technical diving. They basically don't do anything less than 45m and quite often go past 100m. I only join them on the shallower ones as I haven't yet obtained my ccr or trimix tickets. Quite often I'm the only diver on OC.

I find quite funny that these guys (both OC and CC) have no issues in doing extra deco. I guess that my friends, which only do deco on a casual basis, are the ones who have an urge to get off the water.

Food for thought.

D

maxime Wrote:
[...]
> I was comparing the Buhlmann tables with the MK2.

the tables shall be less conservative than a dive
computer

The ZH-L16A set of M-values for nitrogen is further divided into subsets B and C because the
mathematically-derived set A was found empirically not to be conservative enough in the middle
compartments. The modified set B (slightly more conservative) is suggested for table calculations
and the modified set C (somewhat more conservative) is suggested for use with in-water
decompression computers which calculate in real-time.

ddplan.com/reference/mvalues.pdf

w

Just a note: OSTC Mk2 uses M-Values of ZH-L16C, edition 2002, with compartment 1a.

At 36 meters folowing the RDP you have a MANDATORY safety stop of 3 minutes Maxime. So try to find out where you get a 3 minutes deco stop out of the OSTC ....