Any downside to extending the safety stop?

[Ricky B]

In my experience even though staying at 20 to 15 ft for longer than 5 minutes is ok, and not really an issue one way or the other. In my opinion it is vital to do some time at deeper depths ie half the depth of your max on a deep dive, say 150 ft then a minute at 75 is very important and if you have completed a 100 ft dive a minute ( or two) at 60 ft is very beneficial. Then you can do the 30 ft 20 ft and 10 ft to ensure a safe ascent

I think that the thread linked to below refutes the argument that diver should, on his own, determine to make deep stops (as opposed to a stop called for by the diver's dive computer).

http://www.scubaboard.com/forums/basic-scuba-discussions/475224-deep-stops-not.html

 

[Subcooled]

Assuming that you have no issue with getting low on gas, that you won't be separated from your buddy or dive group, and so forth, is there any disadvantage from a DCI perspective to extending the safety stop at 15 feet from 3 minutes to a longer period

No. Absolutely none. The overpressure (0.5 ATA) is so low that no ingassing would take place. I am not an expert in the field of decompression theory, but I got this impression from studying Powells book Deco for divers. I also got the impression that decompression theory is quite complicated and the results depend on your physiology, the blood flow, hydration, rest, the sports you did yesterday, vasoconstriction, state of mind, and the state of the moon. Studying any specific detail at great depth will not offer any advantages as it is the big picture that counts.

I have found out that if I extend the safety stop and make a very very slow final ascent, then I will always feel great afterwards. My experiences do not consitute a valid statistic, but I really cannot see any reason why not to swim an extra half an hour in the shallows, observing fish and crab. This may not depend on bubble counts but on plain old fashioned relaxation.

It can get cold though. Or you may need to pee.

 

[SADS 669]

What are you basing this opinion on? Some study or evidence, or is it just what you think? And 'vital' is a pretty strong word.

I read in the PADI encyclopedia of recreational diving that there is some evidence that an extended safety stop is particularly effective at off-gassing in NDL profiles. I do know that I personally feel less fatigued after doing longer stops; I usually spend 5-10 minutes total at 10-15 feet, depending on the dive and conditions.

Hi Halo,

i am basing this on Pyles experience in Hawaii completing hundreds of dives doing half of his max depth as a stop, Brian Kakuk ( a buddy) from his thousands of dives in caves all over the world but mainly here in the Bahamas and of course my dive computer that for the two weeks in Truk last month ( as an example) had me doing deco stops at 27 metres upwards and then suggested after the last deep stop of 15 metres to go straight to 3 metres which I violently disagree with and I went slowly to 9 then 6 then 3 based on my thousands of dives experience I feel much safer doing this.
I understand that the computer is telling me not to go ABOVE 3 metres but a beginner will not really know this and could get in trouble deco or safety stopping at 3 instead of a gradual move from 9 to 3
i use the word vital because people generally go much much too fast upwards in the danger zone ( In my opinion only) of 100 to 30 ft. If a person is " on the way up" and halts their ascent for a while ( doing a stop) it ENSURES a steady slow ascent instead of going faster than the smallest bubbles which nearly every does.
I am sorry to give the impression of basing this on any study or evidence/fact but I can say I have questioned at length, very experienced divers to ask what works for them. When you add to this that modern computers are stopping you at deeper and deeper depths ( during deco that is) now it makes sense to me.

all the best
kevin

---------- Post added February 3rd, 2014 at 11:57 AM ----------

I think that the thread linked to below refutes the argument that diver should, on his own, determine to make deep stops (as opposed to a stop called for by the diver's dive computer).

http://www.scubaboard.com/forums/basic-scuba-discussions/475224-deep-stops-not.html

very interesting Ricky,
thanks
Kevin

 

[Diver0001]

Assuming that you have no issue with getting low on gas, that you won't be separated from your buddy or dive group, and so forth, is there any disadvantage from a DCI perspective to extending the safety stop at 15 feet from 3 minutes to a longer period?

Will going from 3 minutes to 5 minutes or 8 minutes, say, make any meaningful reduction in residual nitrogen?

Thanks in advance.

One of the most misunderstood concepts in diving is that the safety stop interval is a *minimum* time of 3 minutes. There is no maximum and no way within the realm of scuba diving that one could stay at a safety stop depth for long enough to fully saturate. Moreover, current thinking in decompression theory is that a direct ascent from 1.6 ATA (ie 6m) while fully saturated (which takes 76 hours or more depending upon your decompression model) will probably not result in a bend.

Sadly, divers are often trained that a safety stop is 3 min but they should be trained that a safety stop is at least 3 min

R..