Overshooting NDL and mandatory deco stops

[Blackcrusader]

It's interesting, but I can't really relate it to my diving. As you saw in the post above, my "in the chair" mellowed out RMV was 5.1 l/m, yet the lowest total RMV I've ever recorded on a dive is 10.6 l/m, and most are around 17. Adding any exercise completely changes the picture.
But yeah, it's interesting to measure, just for background. Ask him to hand you the connector to the mask (don't use a mask - it's too hard to get a perfect seal), put it in your mouth and lie there breathing only thru your mouth and see what he reads on his machine.

Dang I forgot to ask on the way out about RMV but will do a checkup tomorrow morning. One eye fixed cataracts and new lens the eye is still dilated but can see so much brighter already. IT's like one eye with cataracts has sunglasses and the fixed one doesn't. One thing though, I walked a mile or so to the clinic from where I am staying. Nurse sat me in a chair to check my pulse and to put drops in my eye. She checks my heart beat and I reply please watch and wait... I sort of put myself into my dive mode and my hear beat dropped... She was happy to see that I could calm myself down as some patients who are about to get their eye lens vaporized by a laser can panic. They were all surprised how calm I remained when getting the first laser burn done. IT's not painful you just look like Tom Cruise in the Minority Report when you get that contraption to keep you eyes open lol

 

[Blackcrusader]

As a side story, I was in the Maldives over the New Year period. and diving with 2 Instructors, 1 AOW candidate, her Dad, and myself. It was the second dive of the day, to 30m depth and all of us except the AOW Candidate where on 28% Nitrox. The lead instructor tells the candidate to watch out for her NDL, and she's on Air. The candidate forgets to so. Both instructors forget to do so and yes she overshot her NDL.

Wow to me it means the instructor should have been on the same supply as the student. That's just my opinion really it's not a policy that others have to follow Also as a student for AOW she is taking part in a course. I never mix with instructors and their students on dives if they are doing classes. I have been on dives from the same boat but separate so the student doesn't mix with fun divers. Also I have even dived with other experienced divers who have been my buddies forget that their dive computer and mine will read differently to NDL over multiple dives over multiple days and have gone into NDL. One Rescue diver who is also a trauma nurse went into deco and never noticed, and had to do 25 minutes at 5m to clear her Suunto. Whereas on my Perdix I never went into NDL.

The lead instructor should also have checked his students computer as intrcutor was on nitrox and the student just followed.

I do dive close to my NDL limits but I do so knowing the risks. I minor overshoot of NDL on most dive computers will not put the student in harms way just means a longer safety stop. My perdix by the way is set to 6m and 5 minute safety stops. If I can I finish the dive on a shallow reef where it might take me ten minutes to go from 5m to surface looking at macro critters.

 

[admikar]

The AOW candidate was put into an extra 2 min safety stop, i.e. 5 Min in total, by her dive computer which was a Cressi.

Please, please, stop saying "extra" or "mandatory safety stop". IF you overshoot NDL, there is no safety stop, there is deco stop, period.
FYI, this is not meant for you personally, more of a general remark.

 

[dberry]

Please, please, stop saying "extra" or "mandatory safety stop". IF you overshoot NDL, there is no safety stop, there is deco stop, period.
FYI, this is not meant for you personally, more of a general remark.

I agree that If the student went beyond NDL, then it's a deco stop, not an "extra safety stop". However, the term "extra safety stop" does apply in some cases. After several days of 5 dives / day on a liveaboard my Perdix switched to 5 min safety stops, which counts as an extra 2 minutes compared to the 3 minutes it normally uses, even though I never exceeded NDLs.

 

[Heat Miser]

Please, please, stop saying "extra" or "mandatory safety stop". IF you overshoot NDL, there is no safety stop, there is deco stop, period.
FYI, this is not meant for you personally, more of a general remark.

Agreed the AOW candidate was put into a 5 min deco stop with her Cressi .... I was on 28% Nitrox, with Adaptive Safety Stop set on the Perdix AI having dived to 30 Meters .... I was put into an extra 2 min safety stop (5 min in total) .... It was hard for the marine life to work out who was doing a deco stop and who was doing an extra 2 min safety stop. They both looked similar, in good trim.

 

[Seaross]

If you don't want to put in the effort required to learn some basic deco science, I'd recommend just following what they taught when I took my PADI OW.

If you overstay your NDL by less than 5 minutes, stay at safety stop depth for 8 minutes and avoid diving for at least 6 hours. If you overstay your NDL by more than 5 minutes, stay at safety stop depth for at least 15 minutes if you have enough gas and avoid diving for at least 24 hours.
(Translated back to English from my OW manual)

Personally, if I overstayed my NDL by more than 5 minutes, I'd spend the rest of my tank at safety stop depth, surface with some 10-ish bar (~150 psi) left and then ask for the O2 bottle when I got back on the boat. And I'd be looking out for any DCI symptoms.

Thank you for answering the question I had to get to page 8 in the thread before I got a answer i really found useful, becuase I think the original question was valid,(what do you do?) made a little more complex by the nitrox variable.

 

[dmaziuk]

It was hard for the marine life to work out who was doing a deco stop and who was doing an extra 2 min safety stop. They both looked similar, in good trim.

... and both were off-gassing, too. Imagine that.

 

[Belzelbub]

I agree that If the student went beyond NDL, then it's a deco stop, not an "extra safety stop". However, the term "extra safety stop" does apply in some cases. After several days of 5 dives / day on a liveaboard my Perdix switched to 5 min safety stops, which counts as an extra 2 minutes compared to the 3 minutes it normally uses, even though I never exceeded NDLs.

Maybe extended would be better. It's not an extra stop, it's just an extension on the optional safety stop.

You must have had your safety stop set to Adapt. You should be able to adjust this in settings. I believe you have 5 choices. 3 min, 4 min, 5 min, Adapt, or Off. I was under the impression that if you had it set to Adapt, the 5 minute safety stop would trigger if you exceeded a specified depth. I don't recall reading anything in the manual that it would go to 5 minutes based on saturation, but I could be wrong. Were your dives on those 5 minute stops deeper than the dives the previous days?

 

[Fastmarc]

You must have had your safety stop set to Adapt. You should be able to adjust this in settings. I believe you have 5 choices. 3 min, 4 min, 5 min, Adapt, or Off. I was under the impression that if you had it set to Adapt, the 5 minute safety stop would trigger if you exceeded a specified depth. I don't recall reading anything in the manual that it would go to 5 minutes based on saturation, but I could be wrong. Were your dives on those 5 minute stops deeper than the dives the previous days?

It will go to 5 min if you reach 5 min NDL in adapt as well.

 

[EFX]

Or, if you exceed 100 ft depth no matter the duration at that depth.