Exceeded NDL by a bit, but computer cleared me. What should I do?

[100days-a-year]

Had full on vertigo and nausea after a normal ascent within NDL. Couldn't open my eyes without vomiting for 3 days.
Returned to diving after a couple months and still had occasional vertigo for years. Did several thousand dives after that.

As far as NDL, I don't consider bumping it during the course of a dive deco if it clears on ascent. But I would recommend more advanced classes if you plan on pushing the envelope.

 

[kaylee_ann]

NDL compromised: allow for a five minute safety stop or longer (gas dependent). Cease diving for the day or take a three hour surface interval. Alternatively, switch to Nitrox.

ah, the excitement i get when i see you've replied to a post is unparalleled. except when i see people rip on you for the inaccuracies. yeah, that one sounds better.

 

[scubadada]

NDL compromised: allow for a five minute safety stop or longer (gas dependent). Cease diving for the day or take a three hour surface interval. Alternatively, switch to Nitrox.

Just go into deco, clears on ascent, not much different than a no stop dive. Back in the day I would do a 5 min SS and resume normal diving. Today, I would monitor my SurfGF, surface with the GF I want, and resume normal diving.

The cease diving for the day or long SI is not indicated.

I nearly always dive nitrox,

 

[DeepSeaExplorer]

It’s not that unusual to go slightly into deco and then have the computer clear before you get to the safety stop. I personally don’t consider this to be an actual deco dive and just carry on as normal. I certainly wouldn’t sit out any dives because of it.

 

[Centrals]

There are various ways to generate different ndl values even from the same computer eg. GF or different algorithms(DSAT and PZ+). I have no idea which is the best but I just follow what my computer indicates on that dive.
Precaution is better than cure ie. never allow the computer to get into deco mode. If that happens then follow the instruction and clear it. Should you continue with the dive or surface immediately after it is cleared or even sit out the dive rest of the day is entirely up to you? I certainly would not if it is only a minor transgression.

 

[Gandalf-the-Diver]

It’s not that unusual to go slightly into deco and then have the computer clear before you get to the safety stop. I personally don’t consider this to be an actual deco dive and just carry on as normal. I certainly wouldn’t sit out any dives because of it.

You mean like this ?

 

[DeepSeaExplorer]

You mean like this ?

I think your computer was giving you a mandatory safety stop because of your max depth.

Once you came shallow, it recalculated at the new depth, giving you more time. Then, it recalculated again when you went deeper.

Once, you started your final ascent, it decided you had been shallow long enough that you no longer needed a mandatory safety stop.

 

[Gandalf-the-Diver]

I think your computer was giving you a mandatory safety stop because of your max depth.

Once you came shallow, it recalculated at the new depth, giving you more time. Then, it recalculated again when you went deeper.

Once, you started your final ascent, it decided you had been shallow long enough that you no longer needed a mandatory safety stop.

Exactly what it was doing. Shearwater Peregrine, set to low conservancy. When I acended at the 1st deco notice, it came out of deco, giving me 27min NDL time. When I was at my deepest, my 1st upward spike started at 2min NDL. I watched the computer countdown to deco obligation before I started to come up. 2nd deco obligation, I just wanted to watch my computer as I got deeper, to see how my NDL was affected, due to the earlier obligation and how deep I had gone. Felt prudence was the best course of action after 2nd obligation was cleared. Stayed shallower, did my 5 min mandatory SS as I went below 100', exited with 900 psi in my 100cu HP Faber. No buddies were spooked on this dive, as I was diving solo. 30cu pony.

 

[inquis]

I think your computer was giving you a mandatory safety stop because of your max depth.

A "mandatory safety stop" is a contradiction of terms. I think it's more clear to consider a stop either mandatory (as in this case) or an optional/safety stop.

The DC assumes an ascent rate of 30 fpm, and the diver would have broken the ceiling had they ascended as expected (or faster). Instead, the diver ascended more slowly than expected, which gave additional time to off-gas and the mandatory stop was no longer needed. The second blip was caused by the on-gassing due to the descent. Similarly, a slower than expected ascent cleared the mandatory stop obligation before arriving.

 

[DeepSeaExplorer]

It’s a mandatory SS if his computer algorithm automatically adds the stop just because he exceeded the recreational limit of 130ft.

I chose to use the mandatory SS terminology, since I don’t know whether his computer was automatically penalizing him, or if it was actually calling it a deco dive at that point.