Overshooting NDL and mandatory deco stops

[Blackcrusader]

After a DAN lecture with Dan Orr, it was obvious to me that I needed a longer safety stop. Neural fluid has about the same half time as blood at around five minutes. Making them 5 minutes has eliminated the need to take a nap afterwards. Those two extra minutes really make a difference.

On my recent dives as I am doing some muck photography on reefs I often have deco cleared safety stop at 5m plus 5 - 10 minutes of diving. Does that help me not be so tired when I do 4 dives a day as a lot of the younger people I dive with tell me after doing 14 dives in 3 days they feel too tired to do another 3 dives for the next day.

I'm off to Bali soon to do some wreck diving and we have 14 straight diving days of 3 - 4 dives a day. Some of those will be late night dives, maybe 1pm or 2am. One thing is that I am not drinking on my dive vacations when I want to do a lot of dives. PS I am not going near NDL and definitely not into DECO so don't worry about my GF.

 

[Nick Ward]

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

if you’ve exceeded NDL you’re into mandatory decompression, not optional (extended or otherwise) safety stops.

 

[Belzelbub]

if you’ve exceeded NDL you’re into mandatory decompression, not optional (extended or otherwise) safety stops.

You must not have understood what I was referring to by Extended Safety Stop. With the Shearwater computers, there is an option to have the Safety Stop extended to 5 minutes based on dive parameters. When it does, you are still under the NDL, and it’s still optional. It’s not a Deco Stop.

 

[Blackcrusader]

You must not have understood what I was referring to by Extended Safety Stop. With the Shearwater computers, there is an option to have the Safety Stop extended to 5 minutes based on dive parameters. When it does, you are still under the NDL, and it’s still optional. It’s not a Deco Stop.

Exactly. I have mine set to 5 minutes for the safety stop but at 6m depth. I often then do another 5 - 10 minutes at 5m or less taking photos or video as lots of marine life often on the reefs at those shallow depths

 

[dmaziuk]

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.

The difference is that Cressi is really *n*l about the depth of that deco-indistinguishable-from-extended-safety stop: it'll trigger it's optional "3/3" at about 6.5 msw and keep counting between that and about 1.5 msw. It'll suspend but not reset the count between 6.5 and IIRC 10 msw. If it's a non-optional "3/3" you have to be at 3+/-1 msw or else.

Must be the "folded" RGBM limitation.

 

[Blackcrusader]

I thought this reply by The Chairman was really noteworthy for people interested in improving their SAC rate.
Always useful to be able to know your SAC rate, calculate amount of air in a tank then calculate how long you can plan a dive especially when on Nitrox some divers will run out of air before they get the NDL at 30m.

Improving my SAC rate

 

[JMarc]

Can you stay calm enough to get yourself both out of difficulty and eliminate your hypercarbia?

Thanks a lot again for pointing me to this message. It was an interesting read. I've one more question, is there a difference between hypercarbia and hypercapnia?

 

[doctormike]

Thanks a lot again for pointing me to this message. It was an interesting read. I've one more question, is there a difference between hypercarbia and hypercapnia?

Same thing. I think that hypercapnea is used more in a medical context, but hypercarbia is another common term for the condition.

Hypercapnia is from Greek ("too much smoke"), while hypercarbia is a mix of Greek and Latin ("too much charcoal").

 

[JMarc]

Same thing. I think that hypercapnea is used more in a medical context, but hypercarbia is another common term for the condition.

Hypercapnia is from Greek ("too much smoke"), while hypercarbia is a mix of Greek and Latin ("too much charcoal").

So my Greek and Latin teachers would vote for hypercapnia. They didn't like mixed roots.

 

[dmaziuk]

The English call them "stems" and I forget that every time I need to use that word in a sentence