What sampling rate on a Cobra/Vyper?

I've just bought a Suunto Cobra - haven't used it yet.

I wondered what sampling rates people out there are using and what the pros and cons are apart from memory limitations.

I understand if you change the sampling rates after you have used the computer it loses track of which dives have already downloaded. Can anyone confirm this?

Thanks

I changed the sampling rate on my Vyper a while back and don't remember having any problems downloading.

I use 10-second sampling to get a more accurate profile. Memory use isn't an issue for me because I download the dives frequently.

Zept

Changing the sample rate did NOT cost me the dives in its memory when I did it.

I think I know what he is asking so I'll clarify it. He's asking if Divemanager will still recognize the dives and download them as new dives, not that the dives will be lost from the dive computer itself. It won't recognize the dives really, but all you have to do is tell the software to ignore these duplicate dives and it will remember them from that point on. I use 10 sec sampling rate also for the above mentioned reasons. I download dives frequently enough so that I don't have to worry about losing any info as it scrolls off the DC memory.

As an example, if you have 30 dives on your DC and download them and then change the rate from 20 to 10 and download again, I believe what it will do is add duplicates of those same 30 dives. I'd have to change it and try it again to confirm that, but I'm pretty sure thats what it did when I changed the sampling rate. Once I found how to ignore the dives and got set on a sampling rate it wasn't a problem any longer.

Aside from having less memory, there are no cons to using a smaller sampling rate such as 10 instead of the factory 20 seconds.

Mine did NOT do that, and I had dives in the machine when I made the change.

Everyone,

Thanks for the responses - sorry, my question wasn't too clear.

Jamie, do you know if the screen displays in real-time but the computer only records to memory as per the sampling rate?

I ask because if you set the sampling rate to 60s is it (theoretically) possible to ascend too quickly without the computer telling you for a minute or so? I've read elsewhere on the boards that some people have experienced ascent rate alarms because they raised an arm too quickly - I'm assuming they're using a very short sampling rate on a Vyper.

Still trying to figure out all the functions the machine has. As I'm not Nitrox trained I need to know what functions to make sure I don't use. Although I read somewhere that Suunto do advise people to use the machine in Nitrox mode and set the O2 to 21% - I presume this is because the machine isn't switchable between air and nitrox modes without enforcing a long surface interval.

I thank you for your advice

The computer displays everything in REAL TIME! The sampling rate is purely for memory/log purposes and will not effect the computer while diving. I've found that setting the sampling rate lower is better for me simply because I get a more accurate profile and less "erroneous" warnings (when you download the profile it recalculates warnings so sometimes you can get an alert from the software that you didn't get on the computer because the computer is real time).

I also don't recall having to ignore dives when I changed the sampling rate to 10seconds, but it was a couple of years back.

The computer displays everything in REAL TIME! The sampling rate is purely for memory/log purposes and will not effect the computer while diving. I've found that setting the sampling rate lower is better for me simply because I get a more accurate profile and less "erroneous" warnings (when you download the profile it recalculates warnings so sometimes you can get an alert from the software that you didn't get on the computer because the computer is real time).

I also don't recall having to ignore dives when I changed the sampling rate to 10seconds, but it was a couple of years back.

Supposedly everything is in "real" time, but i think its a few seconds off. The temp takes a few seconds and it takes a few seconds for the air press to adjust on models like the cobra. Its not like you breath and the numbers instantly drop. It's close enough to call it real time I guess though.