Hello Cliff,
             The 3 slows do show up on the Dive Manager software but when 
I run the dive profile on the Vitek I only see 1 slow.  How "momentary" are 
these periods.  I've got the Vitek set to collect the largest number of samples 
as I download them fairly regularly to my PC so I'm not concerned about keeping 
old dives on the Vitek.  Could the shorter recording period make the Vitek 
actually take samples more often? 

Are you saying that if I raised my arm quickly, for example to adjust my 
mask, and the sample was taken just as I did this I'd get a slow?
I.e what is recorded is an instantanious snapshot rather than an average 
over the sample interval?

Ron.

> The computor monitors depth and time continuously during the dive, so
> when you had 3 momentary periods of fast ascent (i.e. faster than 10
> m/min) it gave you 3 warnings at the time; however it only records
> samples of data into its memory every 20 seconds (or whatever you have
> set the sampling rate to be,) so unless it happened to be recording
> during those fast ascents they will not show later on.
> 
> Cliff.

Hello all,
          I've done some more calculations using the profile information 
used to draw the graph.

While the overall ascent from 34m to 6m was at a rate of 6M/min the detail 
wasn't quite as smooth as the graph led me to believe.
I suspect the graph drawing software is using some sort of smoothing rather 
than just join the dots?

At 16M I rose 2.2M in 10 seconds, which works out at 13.2M/min. 
At 14M I rose 1.8M in 10 seconds, which works out at 10.8M/min. 
At   7M I rose 1.5M in 10 seconds, which works out at  9.0M/min. 
Everything else on the ascent was roughly 1m per interval or 6M/sec between 
34M and 6M.

These were the 3 events that showed up as SLOWs in the profile data and graph 
but only the first one showed up as a SLOW on the Vitek and in the picture 
of the vitek in the top right of the graph when you move through the dive 
in Dive Manager.  All of these are below BSAC's ascent rate guideline of 
15M/min. 

I suspect the Vitek's ascent rate is not linear all the way to the surface 
so the last one might be justified as I'm getting close to the surface but 
BSACs recommeded ascent rate from 6m to the surface is still 6M/min.

I guess what I've learned is 

1) The graph won't show up short relatively fast ascents, other than by the 
SLOW symbols, the graph can still look smooth.
2) Not all SLOW events are reported on the Vitek screen.
3) I didn't realise just how conservative the Vitek ascent rate is. 
4) My ascent wasn't as text book as I thought it was.

Thanks for your time guys,

Ron.

<rmacrae> wrote in message 
news:c40c377853dfc8cbb88cc95ef566@news.btinternet.com...
>
> Are you saying that if I raised my arm quickly, for example to adjust my 
> mask, and the sample was taken just as I did this I'd get a slow?

Exactly.

Cliff.