How low with spare air

[DaleC]

I created this drawing to represent some of my ideas regarding bailouts from depth, AAS (in this case pony) use, and direct ascents for recreational solo dives using air. It graphically shows how I conduct almost all of my dives. Of course, others may hold to different ideas/values based on experience, goals and comfort with risk.

I personally limit my max depth to 100' to avoid narcosis and use a reasonable CESA limit of 50'. In either case, I could, and do, go deeper, but when I do I know I am pushing the envelope of safe limits (for me).



(1.) Represents the pathway I would have to take if I had a major air supply problem without a pony. In both cases (shallow and deep) I would have to directly ascend through all stops to seek the surface.

From shallow depths this is usually not a problem so I will often forgo pony use. In this case I dive small single tanks and conservative profiles. Usually I am vintage equipment diving.

If directly surfacing is not feasible (extended time/exits/overheads) I will take a pony.

Deeper, I face a risk of rapid expansion of gasses from a direct ascent, especially if it is late into the dive. In that case, because I cannot mitigate the risk, I always take a pony.

(2.) Represents the possible pathways I could take if I have a pony bottle (or other means of gas redundancy).

The first preference is ascending along the slope to seek the surface. I prefer this route as it allows a shore exit, as well as avoiding current and unexpected boat traffic.

The second preference is moving promptly to CESA depth for reassessment if I have a (serious) problem deeper down. Here I can either correct the problem, alter my plans or surface with two options available (CESA and Pony).

The third preference is moving promptly up to safety stop depth if I have a problem shallow. This puts me within easy CESA depth and allows me to off gas while I try to correct a problem so that, if I can't, I have already met part of my SS obligation.

Whether deep or shallow, I prefer to move up to these two preset depths and stop when I have a (serious) problem so that, should I not be able to resolve it, I am within a reasonably safe range to access my next air source, the surface.

What I try to avoid is becoming fixated with a problem at depth and getting sucked further into the incident pit before choosing to bail out for the surface. Big problems become small when you know you can reach the surface easily.

I also try to remember what choosing, or not choosing, a pony means. If I choose not to take one I am committing to the (1.) pathway and need to limit my dive in such a way that this is safe to accomplish.

Divers with poor buddy skills also commit to this pathway (1.) but have not completely thought out what this means in regards to risk. They go too deep, stay too long, have no intelligent exit strategies and ignore their available resources.

 

[RJP]

I created this drawing to represent some of my ideas regarding bailouts from depth, AAS (in this case pony) use, and direct ascents for recreational solo dives using air. It graphically shows how I conduct almost all of my dives. Of course, others may hold to different ideas/values based on experience, goals and comfort with risk.

I personally limit my max depth to 100' to avoid narcosis and use a reasonable CESA limit of 50'. In either case, I could, and do, go deeper, but when I do I know I am pushing the envelope of safe limits (for me).

View attachment 171891

(1.) Represents the pathway I would have to take if I had a major air supply problem without a pony. In both cases (shallow and deep) I would have to directly ascend through all stops to seek the surface.

From shallow depths this is usually not a problem so I will often forgo pony use. In this case I dive small single tanks and conservative profiles. Usually I am vintage equipment diving.

If directly surfacing is not feasible (extended time/exits/overheads) I will take a pony.

Deeper, I face a risk of rapid expansion of gasses from a direct ascent, especially if it is late into the dive. In that case, because I cannot mitigate the risk, I always take a pony.

(2.) Represents the possible pathways I could take if I have a pony bottle (or other means of gas redundancy).

The first preference is ascending along the slope to seek the surface. I prefer this route as it allows a shore exit, as well as avoiding current and unexpected boat traffic.

The second preference is moving promptly to CESA depth for reassessment if I have a (serious) problem deeper down. Here I can either correct the problem, alter my plans or surface with two options available (CESA and Pony).

The third preference is moving promptly up to safety stop depth if I have a problem shallow. This puts me within easy CESA depth and allows me to off gas while I try to correct a problem so that, if I can't, I have already met part of my SS obligation.

Whether deep or shallow, I prefer to move up to these two preset depths and stop when I have a (serious) problem so that, should I not be able to resolve it, I am within a reasonably safe range to access my next air source, the surface.

What I try to avoid is becoming fixated with a problem at depth and getting sucked further into the incident pit before choosing to bail out for the surface. Big problems become small when you know you can reach the surface easily.

I also try to remember what choosing, or not choosing, a pony means. If I choose not to take one I am committing to the (1.) pathway and need to limit my dive in such a way that this is safe to accomplish.

Divers with poor buddy skills also commit to this pathway (1.) but have not completely thought out what this means in regards to risk. They go too deep, stay too long, have no intelligent exit strategies and ignore their available resources.

I plan my dive and then keep an eye on my gas and my buddy.

 

[dumpsterDiver]

I created this drawing to represent some of my ideas regarding bailouts from depth, AAS (in this case pony) use, and direct ascents for recreational solo dives using air. It graphically shows how I conduct almost all of my dives. Of course, others may hold to different ideas/values based on experience, goals and comfort with risk.

I personally limit my max depth to 100' to avoid narcosis and use a reasonable CESA limit of 50'. In either case, I could, and do, go deeper, but when I do I know I am pushing the envelope of safe limits (for me).

View attachment 171891

(1.) Represents the pathway I would have to take if I had a major air supply problem without a pony. In both cases (shallow and deep) I would have to directly ascend through all stops to seek the surface.

From shallow depths this is usually not a problem so I will often forgo pony use. In this case I dive small single tanks and conservative profiles. Usually I am vintage equipment diving.

If directly surfacing is not feasible (extended time/exits/overheads) I will take a pony.

Deeper, I face a risk of rapid expansion of gasses from a direct ascent, especially if it is late into the dive. In that case, because I cannot mitigate the risk, I always take a pony.

(2.) Represents the possible pathways I could take if I have a pony bottle (or other means of gas redundancy).

The first preference is ascending along the slope to seek the surface. I prefer this route as it allows a shore exit, as well as avoiding current and unexpected boat traffic.

The second preference is moving promptly to CESA depth for reassessment if I have a (serious) problem deeper down. Here I can either correct the problem, alter my plans or surface with two options available (CESA and Pony).

The third preference is moving promptly up to safety stop depth if I have a problem shallow. This puts me within easy CESA depth and allows me to off gas while I try to correct a problem so that, if I can't, I have already met part of my SS obligation.

Whether deep or shallow, I prefer to move up to these two preset depths and stop when I have a (serious) problem so that, should I not be able to resolve it, I am within a reasonably safe range to access my next air source, the surface.

What I try to avoid is becoming fixated with a problem at depth and getting sucked further into the incident pit before choosing to bail out for the surface. Big problems become small when you know you can reach the surface easily.

I also try to remember what choosing, or not choosing, a pony means. If I choose not to take one I am committing to the (1.) pathway and need to limit my dive in such a way that this is safe to accomplish.

Divers with poor buddy skills also commit to this pathway (1.) but have not completely thought out what this means in regards to risk. They go too deep, stay too long, have no intelligent exit strategies and ignore their available resources.

Makes perfect sense to me. I take a pony for anything over 60 ft usually.

 

[DaleC]

RJP,

When you're solo diving?
(which the above post represents)

But you make an interesting point. You are suggesting the two means of avoiding problems which are generally touted as an argument against pony use, which should work in a well planned competent buddy team. Which is why those things (planning/buddy skills) are so important. It also depends on not making errors and/or having a buddy equally attentive to their gas and partner.

What happens if you have a problem and your buddy swims away because of inattention?
What happens if you have a problem and need alternate gas, which your buddy has not monitored properly?

Because I am, primarily, a solo diver I have no recourse to a buddy, either for gas or assistance. My strategies need to account for self sufficiency and allow for the making of initial mistakes. To believe I will not make mistakes is unrealistic and unsafe.

When sh_t happens to one in a team they can turn to another, who should be whole. When sh-t happens to a solo diver, they can only turn to their already compromised selves. Thus exit strategies need to be more simplified and adjusted to a diver not working from a position of complete wholeness.

 

[GrumpyOldGuy]

I have a simpler approach, but use the same logic (avoid allowing small problems to grow out of control because you are screwing around at depth). If I have a gas supply problem, my dive is done. I have screwed up and I will not trust myself to continue the dive even if I resolve it. I need a time out because I screwed up.

I am heading up to 30'. If I have a buddy, he will be with me. At 30' I can start a min deco 30/20/10 if I have gas (buddy or AAS). That should take care of issues.

 

[TSandM]

Dale, if everyone who dives solo were that thoughtful, life would be good!

I still prefer the non-solo option, but I'm spoiled by having a wide selection of superb buddies.

 

[DaleC]

Yep, everyone has their own plan. The main point is to actually have one and to have thought about the pros and cons of it and maybe talk about it with a buddy if they have one.

I was on a buddy dive once where we encountered high current on the return. Locals will know it as the Keystone Jetty.
We were working hard through it when we became separated (I became distracted by being entangled in some kelp). At that point I decided to exit directly up the jetty wall to the surface. From there I looked for my buddy to surface as well (separation protocol and all that). His plan was to go deeper and swim along the bottom to shore (which took a lot longer). Two non-communicated exit strategies that created confusion and anxiety.

 

[RJP]

RJP,

When you're solo diving?
(which the above post represents)

If I'm planning to dive solo (which is much of my local diving) I do a gas plan for that dive, using VPlanner, which would give me needed gas volume, allow me to plan contingencies, etc.

That said, I do dive double steel HP119's so usually have plenty of gas for anything.