Suunto D4 warning and questions

[darthtony]

Hi, i am a new diver(Just now doing AOW) and i have some questions regarding my suunto D4(not i) dive computer. Last Sunday(3 days ago) i did a night dive and when we surfaced, i noticed a warning sign on the computer, which turned off a couple of hours later.(Manual says that it means i have to have a larger surface interval when it shows that warning) The dive was 53minutes with a maximum depth of 10meters, , very flat profile and slow ascent(We came in from the beach) and completely uneventfull. Why did it show that warning?

Also, i was playing with the dive plan mode, and i noticed that yesterday(40+ hours since the last dive) it showed NDL of 16 minutes on 30m. However i checked again today(64+ hours since last dive) and it shows 17 minutes. Why? Shouldnt i have been completely desaturated after 40+ hours?Does it track nitrogen loading that far out?

 

[DIVEWATCHDOCTOR]

No. It should be totally desaturated by now. Is it a new computer and still under warranty? If it´s not under warranty, try pushing all four buttons simultaneously. This should reset your computer without opening it.

 

[jseyfert3]

From your D4 user manual, page 85 (bolding mine):

"Reduced gradient (variable) "M" values based on diving habit and dive violations.
The "M" values are tracked up to 100 hours after a dive"
​

Page 87:

"Diver Attention Symbol – Advice to Extend Surface Interval
Some patterns of diving cumulatively add a higher risk of DCI; for example, dives with
short surface intervals, repetitive dives deeper than earlier ones, multiple ascents,
and substantial multiday diving. When this is detected, in addition to adapting the de-
compression algorithm, the Suunto RGBM model will in some circumstances also
advise, with the Diver Attention Symbol, that you extend your surface interval."​

 

[darthtony]

Thank you, so this is normal behaviour? Also i didnt mention that the previous morning(>24hr interval) i did two shallow(4 and 8m max depth) 50min dives, so could that be considered "substantial multiday diving" and trigger the Diver Attention Symbol?

 

[DIVEWATCHDOCTOR]

Darthtony:

I appreciate jseyfert3 comment, but your recent diving profiles are not dives with short surface intervals, repetitive dives deeper than earlier ones, multiple ascents, and substantial multiday diving. Any penalization for unsafe diving I've seen, extends up to 48 hours after the violation occurs. So I stick to my theory that there is something wrong with your D4.

 

[stuartv]

If it is normal for that computer to consider you to be not fully desaturated 40+ hours after the dives you did, I would consider getting a different kind of computer...

IOW, I am inclined to agree with @DIVEWATCHDOCTOR that something is wrong with that computer.

 

[darthtony]

When it enters plan mode it says Desat 0:00 which i suppose means i should be fully desaturated. Anyway, I sent Suunto an email describing the behaviour to see if it is an actual malfunction(It is very weird that it would fail this way). If anyone has knows anything about this behaviour it would be really appreciated.