No More 10 ft Stops?

[waterpirate]

Isn't the navy still focused on " bend and mend " and a on deck chamber for diving operations???? That makes a correlation between todays puter modeling and their tables, marshmellows and pineapples, unless you are IN the navy.
Eric

 

[SailNaked]

I wonder if it has to do with the lower fitness standards and overall obesity.
N

Dude did you just call the Navy, Obese? don't tell the Russians,, er I mean Iraqis, er um North Korea, dang it who is the enemy at this time?

Besides the Navy does its 30ft stops on O2, nothing to do with mortals.

 

[JamesK]

I do not dive deep, but do partake in deco dives. I still finish with a 10' stop. Once I have cleared my 20' deco obligation, on O2, I move at a rate of 10'/min to 10' where I complete an additional stop. I then very slowly surface. Overkill? Possibly, but it works for me.

 

[rookers]

Actually, 10' stops are still used and still very necessary. While for most decompression dives this isn't true, when you're doing a deep dive (think 250'+), your CNS clock is going to get up there fast. Not moving from 20' to 10' could put you at risk for oxygen toxicity.

I must be dead or bent or toxed then

It's not a universalism IMO. I have not done a 10' stop in 7 years or so on a staged decompression dive. I do 3 (or longer for more significant exposures) minutes up from 20' at the end of a staged decompression dive. O2 clock is planned for.

 

[Dsix36]

I dive a rebreather and when I get to my 20' stop, I will almost always flush my loop with oxygen. Essentially I am decoing on oxygen this way. I am no expert in deco algos or any of that stuff but someone much smarter than me has been slowly teaching me a few things.

It seems that when the 20' stop is cleared, moving up to a shallower stop makes good sense. There is lttle if any difference in the chance of getting bent, but there evidence that there is less risk of oxygen toxicty.

I now move up to 10' if possible, especially if it was a dive with a major deco obligation.

Like I said, I am no expert, but this makes sense to me.

 

[decompression]

I do 1' stops from 250', just very slowly and some are longer than others!

 

[NAM001]

Did not we try this in some other thread. and we found out that a 10 ft stop decreased the total deco time as compared to 20' being the shallowest stop. I will run it again.

Done on my Shearwater v4.6

100 ft 45 min bot rmv .53 min deco depth 10' grad 30/85 100% o2 starting at 20' div tot 64min 19 deco
100 ft 45 min bot rmv .53 min deco depth 20' grad 30/85 100% o2 starting at 20' div tot 70 min 25 deco

 

[ianr33]

Did not we try this in some other thread. and we found out that a 10 ft stop decreased the total deco time as compared to 20' being the shallowest stop. I will run it again.

Done on my Shearwater v4.6

100 ft 45 min bot rmv .53 min deco depth 10' grad 30/85 100% o2 starting at 20' div tot 64min 19 deco
100 ft 45 min bot rmv .53 min deco depth 20' grad 30/85 100% o2 starting at 20' div tot 70 min 25 deco

That's odd. Shouldn't make any difference . V planner gives the same times no matter if the last stop is 10' or 20'

A last stop at 20' will be longer on air, but not on O2.

 

[NAM001]

My guess is that doing the 10' stop after teh 20 increases the off gassing rate. So you trade say 10 min of stop at 20 for 8 at 20 and 4 at 10. Doublr thr dp by going to 10 and cut the stop time in half. So 100% o2 stops the intake. if the body (deco wize) is at say 40 ft and you compare your depth of 20 vs 10 ,,,then 10 would have a higher dp and thus a faster off gassing fo the remaining system gasses. off gassing has to be pretty slow when the cells are at 30' and the body is at 20 compared to 10. On air you are on gassing and off gassing so to speek so th difference should be less than on o2. Pls no one flame me, it is only a logical guess. some other thoughts . Is your vplanner using the 30/85 gradient in its calcs? I would think that if 20 ft is your last stop and you deco to a given level it should take longer than if you last stop is 10' to get to the same given level, once again because of the larger dp causng higher higher off gas rate per the position on the 30/85 gradient line. I would think that this effect would be more pronounced with longer deco obligations since the slower tissues would become the driving factor of extended deco periods at shallower depths. kind of like using 100%o2 cuts deco time in half compared to 50% o2. Another benifit of hte 10 ft stop is that you dont have to carry so much deco gas because of the shorter total deco time. Sorry for the poor verbalization.

That's odd. Shouldn't make any difference . V planner gives the same times no matter if the last stop is 10' or 20'

A last stop at 20' will be longer on air, but not on O2.

 

[PfcAJ]

My guess is that doing the 10' stop after teh 20 increases the off gassing rate. So you trade say 10 min of stop at 20 for 8 at 20 and 4 at 10. Doublr thr dp by going to 10 and cut the stop time in half. So 100% o2 stops the intake. if the body (deco wize) is at say 40 ft and you compare your depth of 20 vs 10 ,,,then 10 would have a higher dp and thus a faster off gassing fo the remaining system gasses. off gassing has to be pretty slow when the cells are at 30' and the body is at 20 compared to 10. On air you are on gassing and off gassing so to speek so th difference should be less than on o2. Pls no one flame me, it is only a logical guess. some other thoughts . Is your vplanner using the 30/85 gradient in its calcs? I would think that if 20 ft is your last stop and you deco to a given level it should take longer than if you last stop is 10' to get to the same given level, once again because of the larger dp causng higher higher off gas rate per the position on the 30/85 gradient line. I would think that this effect would be more pronounced with longer deco obligations since the slower tissues would become the driving factor of extended deco periods at shallower depths. kind of like using 100%o2 cuts deco time in half compared to 50% o2. Another benifit of hte 10 ft stop is that you dont have to carry so much deco gas because of the shorter total deco time. Sorry for the poor verbalization.

Doesn't V-Planner use VPM? And aren't gradient factors (like 30/85) a Buhlmann thing?