Pony Tips

[MarkA]

Come on please quit with the insults and bloviations.

New word learnt (bloviations)

Interested to know your safety stop depth. Probably not at the 6m end of the safety stop depth range due to the altitude?

If using a shearwater? What does the GF99 and SurfGF say during the safety stop. Could you simulate using 100% O2 to see what improvements there are?

 

[johndiver999]

Thanks good input and appreciated. I am after any improved reduction of microbubbles/decompression stress; even if very small ['hardly anything'] I want, no need, such a reduction due to previous injuries, age, decades of deep dives and current dive profiles to NDL. Unlike others on this forum who use 36% or 32% 'back-gas' even though EAN certified and having dived it in 80s, I currently only dive 21%.

My dive depths preclude using EAN and getting an EAN fill where I live would involve a 9 hour drive. I have a compressor for 21% fills and no intent or ability to mix my own EAN.

Yes, I concur dive shallower, use EAN as primary/safety stop gas and give a buffer from NDL would be another way to accomplish bubble reduction and possibly elimination. But, other than backing off NDL the other options do not fit why and how I dive.

My proposal to use EAN at safety stop when diving 21% is not a new concept and has been recognized as benefit for a long time. But I do not say or recommend that anyone else do what I plan on doing. You have mentioned other means to accomplish my objective and I do appreciate that perspective and suggestions. Again, let each diver decide how they conduct their dives.

Will add a perspective. You mentioned using EAN on safety stop as a "poor attempt to get rid of it in the final moment"; I understand what you said and meant, but consider that any reduction of tissue or blood nitrogen gradient that is above Pp pressure at surface benefits the diver and reduces the chance of asymptomatic injury. The final moment, surfacing, is the crucial decompression moment.

Thanks again, exchange was helpful for me.

Not much of this makes no sense to me.
How do you fill the pony bottle with nitrox if it is too far away to get nitrox fills?
If you are too deep to dive nitrox then why take nitrox in a pony bottle so deep that it is not usable as a bail out gas?
The dangers of taking the "pony bottle" into lethal depths, seems larger than the potential benefit of decompressing with it on a no-deco dive?
How deep are you diving with no usable redundancy in case you have a problem at depth?

 

[LI-er]

Not much of this makes no sense to me.

In all fairness neither does this.

 

[Wallowa]

Not much of this makes no sense to me.
How do you fill the pony bottle with nitrox if it is too far away to get nitrox fills?
If you are too deep to dive nitrox then why take nitrox in a pony bottle so deep that it is not usable as a bail out gas?
The dangers of taking the "pony bottle" into lethal depths, seems larger than the potential benefit of decompressing with it on a no-deco dive?
How deep are you diving with no usable redundancy in case you have a problem at depth?

Folks my posts are based on my diving education, training, experience and profession as a Diving Safety Officer; BUT they are only my views and I do not impose them on others. Each diver should be free to decide how they conduct their dives. Dialogues that exchange information are positive but criticisms are not warranted on another person's choices.

I will try one last time...if you reference Wienke, Bennett, Bove, Gilliam, Mount, Edmonds, Dueker, Barsky, Lippmann, et al, they state the benefit of using a high % of oxygen at safety stops...the 'oxygen window' benefit.....even on dives within the NDL....when a diver surfaces they will have microbubbles/nuclei in the circulatory system....removing or diminishing those 'silent bubbles' reduces the chance of asymptomatic tissue damage...using a high % of oxygen at a safety stop is a standard of practice....even shallow mandatory decompression stops use high % of 02....my use is only at a shallow safety stop....my primary gas is 21% air.

I am NOT going to use EAN as a "bailout bottle" or emergency gas supply....but only at shallow safety stops....no "lethal depths".....the concept of redundancy "at depth" is a joke to me......I dive deep but do it in 1/3s...I have never run out of gas in 69 years of diving, never....this current craze to double up all your gear does not make you safer, judgement and in-water skills makes you safer....I see the "two of everything" as just more failure points and for 'joining the club' since the proliferation of "Tech"....again only my perspectives and how you dive or the gear you use is strictly your business. No judgements on your actions or choices.

Question was asked at what depth when diving at altitude do I make a safety stop. Currently diving at 4,300ft ABSL I make safety stop of 5+mins at 15-17ffw [NOAA]. This is usually a swimming along that depth contour 'stop'. Slow swim and extending stop time when feasible. Another question....I plan to fill a 13cf pony bottle with EAN40 using a whip from a 117HPcf bottle; this will allow many sufficient fills of 13cf before pressure drops in 117 enough that I need to re-fill the 117.

Not sure why so many of these threads end up in persons not just espousing opinions or exchanging information but rather telling others that their choices 'doesn't make sense' or are wrong. Nobody has the keys to the kingdom and is truly a 'know it all'. I certainly am still learning. One size does not fit all; keep an open mind and always entertain that "I might be wrong", I operate from that premise. Out here and I will stay off this thread so as not to generate more negativity.

DSO

 

[davehicks]

Chrisch,

Not complicated....or so it seems to me....yes, safety stops are just that, to enhance the removal of nitrogen from tissues and blood with a stop in ascent; not required but beneficial....to further improve that removal of XS nitrogen you use higher %s of oxygen in the breathing gas at a safety stop to take advantage of the 'oxygen window'....as I dive air [21%] and within NDL, my safety stops are to assure that I have removed as much XS nitrogen as possible and reduced or eliminate as many microbubbles as possible before surfacing....extra critical because I often dive above 7,000 ft ABSL...I will be using EAN in the future on my safety stop and since I dive 21% I will need a small bottle of EAN for the safety stop.


As for other posts with vitriolic comments, none of us are the "smartest person in the room".....to each their own. Keep it civil and informative.

DSO

I mostly dive a CCR, so at a safety stop I am generally breathing about a 60% oxygen mix during my 20-foot safety stop. While this certainly does help with off gassing to a degree, the standard 3-minute safety stop is not long enough to substantially move the needle. I always have SurfGF displayed on my computer, and it will only drop a couple of points across 3 minutes on a 1.0 ppo2 at 20 feet. (about 60%} If you were hanging out for 10 or 15 minutes it would add up a lot more, but you'd also be adding some margin if you did the same on 21%.

 

[davehicks]

New word learnt (bloviations)

One of my favorites!

 

[davehicks]

Folks my posts are based on my diving education, training, experience and profession as a Diving Safety Officer; BUT they are only my views and I do not impose them on others. Each diver should be free to decide how they conduct their dives. Dialogues that exchange information are positive but criticisms are not warranted on another person's choices.

I will try one last time...if you reference Wienke, Bennett, Bove, Gilliam, Mount, Edmonds, Dueker, Barsky, Lippmann, et al, they state the benefit of using a high % of oxygen at safety stops...the 'oxygen window' benefit.....even on dives within the NDL....when a diver surfaces they will have microbubbles/nuclei in the circulatory system....removing or diminishing those 'silent bubbles' reduces the chance of asymptomatic tissue damage...using a high % of oxygen at a safety stop is a standard of practice....even shallow mandatory decompression stops use high % of 02....my use is only at a shallow safety stop....my primary gas is 21% air.

I am NOT going to use EAN as a "bailout bottle" or emergency gas supply....but only at shallow safety stops....no "lethal depths".....the concept of redundancy "at depth" is a joke to me......I dive deep but do it in 1/3s...I have never run out of gas in 69 years of diving, never....this current craze to double up all your gear does not make you safer, judgement and in-water skills makes you safer....I see the "two of everything" as just more failure points and for 'joining the club' since the proliferation of "Tech"....again only my perspectives and how you dive or the gear you use is strictly your business. No judgements on your actions or choices.

Question was asked at what depth when diving at altitude do I make a safety stop. Currently diving at 4,300ft ABSL I make safety stop of 5+mins at 15-17ffw [NOAA]. This is usually a swimming along that depth contour 'stop'. Slow swim and extending stop time when feasible. Another question....I plan to fill a 13cf pony bottle with EAN40 using a whip from a 117HPcf bottle; this will allow many sufficient fills of 13cf before pressure drops in 117 enough that I need to re-fill the 117.

Not sure why so many of these threads end up in persons not just espousing opinions or exchanging information but rather telling others that their choices 'doesn't make sense' or are wrong. Nobody has the keys to the kingdom and is truly a 'know it all'. I certainly am still learning. One size does not fit all; keep an open mind and always entertain that "I might be wrong", I operate from that premise. Out here and I will stay off this thread so as not to generate more negativity.

DSO

I also do this Transfilling routine all the time. I use a 40cf 3000psi bottle for diluent and after a couple of dives it is down to about 2500 psi. I use a 100cf 3500psi tank to transfill to the 40cf tank, but I use a booster to ensure I get the bottle to 3000psi again. Without a booster you are quickly going to be shorter and shorter fills on the 13cf bottle.

 

[LI-er]

the concept of redundancy "at depth" is a joke to me

Yes it's hilarious to think a diver might carry duplicate life support items in fact the tears are streaming down my face as I struggle with bladder control as I helplessly giggle st the whole silly idea.

Even more amusing is the thought of only having redundancy at a 15' optional safety stop.

 

[grantmac]

If you actually cared about risk reduction you'd be using nitrox from redundant tanks throughout the dive.

 

[johndiver999]

Folks my posts are based on my diving education, training, experience and profession as a Diving Safety Officer; BUT they are only my views and I do not impose them on others. Each diver should be free to decide how they conduct their dives. Dialogues that exchange information are positive but criticisms are not warranted on another person's choices.

I will try one last time...if you reference Wienke, Bennett, Bove, Gilliam, Mount, Edmonds, Dueker, Barsky, Lippmann, et al, they state the benefit of using a high % of oxygen at safety stops...the 'oxygen window' benefit.....even on dives within the NDL....when a diver surfaces they will have microbubbles/nuclei in the circulatory system....removing or diminishing those 'silent bubbles' reduces the chance of asymptomatic tissue damage...using a high % of oxygen at a safety stop is a standard of practice....even shallow mandatory decompression stops use high % of 02....my use is only at a shallow safety stop....my primary gas is 21% air.

I am NOT going to use EAN as a "bailout bottle" or emergency gas supply....but only at shallow safety stops....no "lethal depths".....the concept of redundancy "at depth" is a joke to me......I dive deep but do it in 1/3s...I have never run out of gas in 69 years of diving, never....this current craze to double up all your gear does not make you safer, judgement and in-water skills makes you safer....I see the "two of everything" as just more failure points and for 'joining the club' since the proliferation of "Tech"....again only my perspectives and how you dive or the gear you use is strictly your business. No judgements on your actions or choices.

Question was asked at what depth when diving at altitude do I make a safety stop. Currently diving at 4,300ft ABSL I make safety stop of 5+mins at 15-17ffw [NOAA]. This is usually a swimming along that depth contour 'stop'. Slow swim and extending stop time when feasible. Another question....I plan to fill a 13cf pony bottle with EAN40 using a whip from a 117HPcf bottle; this will allow many sufficient fills of 13cf before pressure drops in 117 enough that I need to re-fill the 117.

Not sure why so many of these threads end up in persons not just espousing opinions or exchanging information but rather telling others that their choices 'doesn't make sense' or are wrong. Nobody has the keys to the kingdom and is truly a 'know it all'. I certainly am still learning. One size does not fit all; keep an open mind and always entertain that "I might be wrong", I operate from that premise. Out here and I will stay off this thread so as not to generate more negativity.

DSO

This is a ridiculous statement: "but criticisms are not warranted on another person's choices."

Of course it is appropriate to criticize a person's choices - particularly if they are incapable of defending them in a logical manner (or if they are illegal or harmful to others).

This is a solo forum, so it appears that you are diving solo deep on air, presumably deeper than maybe 130 and advocating for no redundancy, because... why again... you are going to only plan on using a third of your gas? And of course you have never had a failure at depth and you have a lot of dives - so this is why you don't follow the recommendations of every training agency wrt redundancy? Is that the train of thought being applied here?

I think most people use the term "pony bottle" to mean an emergency bail out bottle - to be used from depth. What you are describing is a decompression stage bottle.

Again your comments (above) are not making sense to me... You are planning to do a short deep dive on air with a single tank and only consume 1/3 of the volume. that means that you have 2/3 of the volume to safely reach the surface and perform safety stops.

Diving in this manner will yield you a huge margin of safety with regard to gas volume and capacity to decompress (assuming no failures of course). If you have this huge volume of gas for ascent, how does taking a stage bottle of nitrox do you any measurable good? It makes no sense to me.

Isn't the larger danger, a problem/failure of your single tank of air at a very deep depth, rather than forgoing the truly miniscule reduction of decompression stress from use of nitrox on the safety stop from a no-deco dive? In other words.. you got a sh!t ton of extra air, why not just deco on that and carry a bailout bottle that is usable and can actually potentially provide some benefit? And.. if you do want to reduce decompression stress, just use more of the huge reserve of air you have and hang for the additional 60 seconds - which is probably more than the benefit of nitrox- but I am guessing on that supposition.