New CF 65 Safety stop feature

[Aquazone]

Hi HW

I have noticed the new Safety stop will only activate shallower than 5m. So a stop at say 5.5m the stop will not start or continue to count. Can this be made to start at 6m and shallower. It's a great addition but quite useless at a stop of deeper than 4.9m.

Thanks.

[Stephane]

Hi,

You've got a brain, use it! Stop by yourself 3mn at whatever depth you want and here is your «safety» stop.

[scubatinoo]

This will never end...

[Aquazone]

Erm...

I thought it was a simple question...If I had of wanted a smart arse comment from a clown I would have called a circus...do you work at a circus Stephanie?

[Stephane]

No, but I have a brain. And I know how to use it.

[swissdiving]

I can vaguely remember seeing a comment from Matthias that he is NOT going to make any changes to the Safety Stop function.

But by the life of me I can't find that entry anymore.

[scubatinoo]

swissdiving Wrote:
-------------------------------------------------------
> Matthias that he is NOT going to make any changes
> to the Safety Stop function.

But maybe he should...

[DiverM]

Aquazone Wrote:
-------------------------------------------------------
> Hi HW
>
> I have noticed the new Safety stop will only
> activate shallower than 5m. So a stop at say 5.5m
> the stop will not start or continue to count. Can
> this be made to start at 6m and shallower. It's a
> great addition but quite useless at a stop of
> deeper than 4.9m.
>
> Thanks.

I have had the audacity to make a small adjustment to the definitions.asm file and to compile the firmware myself: Adjusted Firmware v2.50

B)-

[Aquazone]

Thanks Hansjoerg,

Maybe Matthias might revisit the stop. By allowing CF 65 to commence from 6m would make it a more practical and usable application (CF 65). I take one of mine with me (2N) whatever diving I'm doing, they are alive with information in whatever visibility. They don't stay home just because I'm not doing a deep tech dive.

Thanks,

OSTC 2N 2241 / 3797

[Aquazone]

DiverM

It's good to know that it's possible. Making adjustments like that are beyond me. I'll just have to hope and wait to see if the next firmware makes any changes to CF 65.

Thanks

OSTC 2N 2241 / 3797

[Bardass]

Aquazone Wrote:
-------------------------------------------------------
> Thanks Hansjoerg,
>
> I take one of mine with me (2N) whatever diving I'm
> doing, they are alive with information in whatever
> visibility. They don't stay home just because I'm
> not doing a deep tech dive.
>
> Thanks,
>
> OSTC 2N 2241 / 3797

So you'd rather leave your OSTC at home instead of using the stopwatch ?

[scubatinoo]

Who needs the stopwatch? I'd rather need a countdown...

[Bardass]

Waouhh
3 minutes ?
5 minutes ?

[scubatinoo]

Sometimes 8 Minutes, depending on how i like my eggs for breakfast...

[Bardass]

So use stopwatch
Because, without sound, countdouwn is useless

QED (quod erat demonstrandum)     

[DiverM]

Bardass Wrote:
-------------------------------------------------------
> So use stopwatch
> Because, without sound, countdouwn is useless
>
> QED (quod erat demonstrandum)     


Same can be said of the deco stop countdown..... useless, because there is no sound.
And countless other parameters and warnings... No sound, so they are useless?

Maybe you should sell your MkII and just use a bottom-timer?

I know perfectly well at what depth and for which time to do a safety stop. I Just happen to like the automated countdown.
Besides, deco stops are displayed in a similar fashion, nobody seems to have a problem with the fact that there is no sound signalling the start, nor the end of those?

I know of cave divers, not ever exceeding the NDL, but going up and down several times between 1 and 15 meters, they sure appreciate a safety stop countdown.

Why?

Because it is useful automation.

Just like blinking better gas is useful automation.

[adrian-bluescuba]

@scubatino, aquazone and ...

please check this link and read carefully hw´s coment from 09:40PM:
read.php?2,9314,page=4

please not again.

cheers
adrian

[scubatinoo]

I know this comment quite well. Maybe you're going to ask some others about it...

[Aquazone]

Greetings,

After a good mights sleep following two lovely dives with my 2N yesterday (which goes on every dive Bardass as I stated) It seems the debate goes on.
CF 65 an automated countdown and a great feature for certain types of diving. Those who dont want it or dont use it just simply leave it turned off. The anti CF 65 want us to use the stop watch or count numbers in our heads, or buy another computer. Well we quite like the 2N and we also would like to use the CF65 feature. All we are asking is to allow it to start at 6m so it can be used effectively to dive and have a countdown that will run at a depth of 6m instead of 5m.
Anti CF65...cut us some slack and give us a break. Just because you may not like it, well there are a lot of people who do.

Thanks,

OSTC 2N 2241 / 3797

[nakatomi]

DiverM Wrote:

> I know of cave divers, not ever exceeding the NDL,
> but going up and down several times between 1 and
> 15 meters, they sure appreciate a safety stop
> countdown.

Actually that´s a perfect example why this stop is such a useful feature and also why it is required by all major agencies that offer cave training. Thank you for bringing that up!

[Clownfish]

I regularly do deep decompression dives, but I also dive non-deco dives. I believe that it should start from 6 metres and also go for a user defined time (eg 0 or 3 or 5 mins). I accept that perhaps as it is now it cannot be changed to do 5 mins. I use DiverM's version and it works great.

I would prefer if this was all in the "offical" version, but if it is not, I will continue to use DiverM's version.

[Peppe]

I can understand people against the 3 min safety stop on OSTC, they see it like a turn to recreational diving from a staight tech diving computer.
Nevertheless, there are divers (like me) who uses this computer as a tool on their job, e.g. running a diving centre, in addition to deep or multigases dives.
When diving with recreational divers the new CF65 is extremely helpful because these divers have the 3 min safety stop on their mares, suunto, uwatec etc. etc. diving computers. Very often new students don't have a dive computer that's why is great to show them the countdown during the safety stop.
At the end, I consider CF65 a big add-on to this marvelous computer.

[scubatinoo]

OK Folks... A new Argument for Safety Stops after every dive! Please read this:
[quote]The most important safety factor is not the algorithm you select, rather that you follow very closely the recommendations of that algorithm and safe diving in general. Regardless of the decompression algorithm you use, it would be unwise to immediately surface once you have cleared your required decompression stop obligations. Doing so would result in your surfacing with the absolute maximum saturation allowed by the algorithm you selected, i.e. incurring the maximum risk. As with recreational NDL diving, after clearing your required decompression you should always perform an additional 3 to 5 minute 'safety stop' at your last stop depth.[/quote]

Original Text can be found here: http://www.divegearexpress.com/computers/predator.shtml

"Additional 3 to 5 Minutes at your last stop" means 3 to 5 Minutes ether at 6m or at 3m. So it's one point more to change the range of the actual safety stop implementation - and to turn it on even on Non-NDL-Dives...
-D

[smcmullan]

I've no specific interest in this feature but I hope to make some positive comments

* I've read the HW comments that a 6m safety stop is inefficient compared to a shallower dept for NDL dives and will not implement for that reason. I'll assume they have done their research so am happy to accept that. Yet despite that there are still calls to allow the depth to be configurable to a max depth of 6m. I think the reason for this is probably standard protocol i.e. that is the depth they stop at because that is how they have been trained.

Now the question is whether the device will facilitate that or prevent it based on research into the effectiveness of safety stops. Now I've already noticed certain CFs that carry the warning - "This is critical custom function! ... Do NOT dive with a OSTC configured that way" so I'm wondering why the reluctance to allow a diver to configure a 6m safety stop if they want to?

Now to the very important point scubatinoo mentions above:

* Leaving aside the controversial issue of the depth/duration of the safety stop, the aspect that I see far far more abused is the ascent rate from the last stop to the surface. I see a lot of divers doing a stop at 5-6m for 3minutes and then thinking nothing of a rapid ascent to the surface. I can't remember which agencies prescribe what protocol for this but I know BSAC say the time to go from 6m to the surafce should be at least 1 minute.

* If people are tired of reading about these "recreational" features for a "technical" dive computer then consider that even for very deep dives with deco lasting several hours the deco computer will clear at your last stop eventually but normally does not offer any advice or control on how to exit to the surface. I think this can be critical on deep dives. Amongst the divers I know we can take many minutes to go from the last stop (normally 4.5m) to the surface. Each diver seems to employ an informal method but there could be scope here for a nice feature for the OSTC (optional of course ) that would benefit recreational AND technical divers.

Hope that wasn't too controversial

[scubatinoo]

I was trained to ascend with 1 meter per minute from 6m to the surface. so virtually i'm doing a safety stopp for 3 minutes between 6 and 3 meters, and then a slow ascend...