Sorry to resurect an old tread, but I just ran into this problem myself and was hoping for a bit more info. The info here already has been tremendously helpful.
I've gotten several diver alerts over a four day period, here's the profiles: (all are shore dives, with asents following bottom contour)
On Suunto Vyper
SI >99h
Dive 1: A0/P1, Max=72', Avg=37', Time=39min,
no ascent violations, safety stop cleared, no "above 4ft"
SI=48:39, no DA displayed
Dive 2: A0/P0, Max=24', Avg=20', Time=46min,
no asent violations, no safety stop indicated, no "above 4ft"
SI=3:45, DA displayed and cleared
Dive 3: A0/P0, Max=19', Avg=13', Time=48min,
no asent violations, no safety stop indicated, 3 "above 4ft" instances near end of dive
SI=5min (barely a new dive) DA displayed and NOT cleared
Dive 4: A0/P0, Max=8', Avg=6', Time=9min,
no asent violations, no safety stop indicated, several "above 4ft" instances
SI=20:32 DA displayed and cleared
Dive 5: A0/P0, Max=43', Avg=23', Time=43min,
no asent violations, safety stop cleared, 2 "above 4ft" at very end of dive
SI=0:50 DA displayed and NOT cleared (although DIVEPLAN said it would clear between 40 and 43 min SI)
Dive 6: A0/P0, Max=21', Avg=12', Time=38min,
no asent violations, no safety stop indicated, 5 "above 4ft" instances at near end of dive
SI=37:00+, DA displayed and cleared
The only two correlating factors I can see (from the diver accessible data):
1. the "above 4ft" instances - which is Suunto's magic depth to define a dive, according to the Instruction Manual. New England lobstering at low tide often means a lot of "above 4ft" instances.
2. Dive 1 (and my dives before that) were with 20 sec sampling. Dives 2-6 had 10 sec sampling.
I have 18 dives on my Vyper and don't think I've gotten the DA before (at minimum I've never violated it).
[/u]So here are my questions: [/u] Maybe BRW would be willing to grace us with his knowledge one more time
1. Is there a correlation between "above 4ft" instances and DA? Can DA be avoided by staying above 4ft once that depth is reached at the end of the dive?
2. If you start a dive with DA displayed, how much is the penalty to the NDLs? What about starting dive 2 and 3 in a series with DA still displayed.
3. Does the sampling rate affect how the model calculates tissue saturation and/or microbubbles.
4. What conditions produce a DA, assume no stops missed and no assent violations?
5. Will starting too many dives with DA displayed ever lock me out?
6. Why didn't the DA displayed between dives 5 and 6 clear after the period of time DIVEPLAN said it would?
Basically, I just want more information on what my computer is telling me. I intend to listen to it - but want to know what it's thinking. Also, in my dive planning I would like to be able to predict when I will get a DA, just as we are able to predict available NDL.
If this is too much - just tell me to suck it up and call Finland.
Thanks y'all.
