Question Took my first deco, help me to understand my computer behavior

[scubaeng]

Hello there,
I took my fist deco during my last dive but I'm not sure that my sw peregrine worked well. So when I was at 30 m, my peregrine warned me that I was few minutes from NDL (I got conservatism on medium). I started ascending very slowly as usual thinking that NDL would increase soon, however when I was around 21 m the peregrine went on deco mode advising 1 minute deco stop at 3 m. I've never had any dive on deco mode, so knowing that would be very unlikely to got injured, I just thought "OK I will just do the deco stop at 3 m instead of the usual safety stop and everything will be fine". I started ascending again with my peregrine in deco mode but when I was at 12 m the computer went out of deco mode and just displayed a very high 99 NDL and just called the safety stop around 6 m for 5 minutes. Is it correct that my peregrine exit deco mode? I correctly understood that I just to do my deco stop at 3 m at the end of the dive? You can find the graphic of the dive in the attached. Thank you.

 

[scubadada]

You cleared your short deco obligation on your ascent and the computer went back into no stop/NDL mode. Either your safety stop is set at 5 min or you are in adaptive mode and got 5 min because you had exceeded NDL.

 

[scubaeng]

Thank you, I thought the computer should be locked in deco mode till the end no matter what. And yes I have the adaptative safety stop. Seems all all went well.

 

[broncobowsher]

I have not run recreational mode in a long time, but typically I will see a notification "Deco cleared" once out of deco window.

As mentioned above, clearing deco doesn't suddenly start at 6m or 3m. That is what the fancy computer does for you so you don't need a book of tables with you, or the dumbed down single table that we all learn with.

 

[johndiver999]

I don'r know that particular computer, but what it sounds like is... You were ascending from a non-deco dive, but you went so slow that it clicked over into required deco - because you were too long at considerable depth.

As you continued your (excessively) slow ascent, the computer cleared the required deco at a depth well below the (previously) required deco stop.

That is what my cheap computer will do sometimes.

In other words, if you come up too slow (from deep) on a deco dive, you will get MORE deco time. If you move slowly through the relatively shallow depths of less than about 35-50 ft, a very short required deco stop may clear itself below 10 meters.

 

[Alex Ouroboros]

You cleared your short deco obligation on your ascent and the computer went back into no stop/NDL mode. Either your safety stop is set at 5 min or you are in adaptive mode and got 5 min because you had exceeded NDL.

Exactly right!!!
On the ascent you’ve off gassed what was your depression penalty as it was only slight. (On deep long decompression dives it does sometimes happen that the first required stop is no longer there when you get to that depth and the first stop is where you expected the second,,, but don’t start doing that sort of tomfoolery yet please)

Enjoy your brush with Deco