Depends on how far down the “what if” rabbit hole you are willing to travel. Is a sudden and complete failure of your system possible…yes. Is it probable…no. If you are cruising at 100 mph and your car suddenly dies, you gradually slow and move off the road. If you are 100 feet under water and you go to take a breath that is not there, you have a much larger problem.
An OOA scenario at 100 feet and your dive buddy is 30 feet away looking at something else besides you can create all kinds of drama. The logical action would be to swim the 30 feet to the buddy versus the 100 feet to the surface but I would argue that the average panicked diver in this type of situation will not respond logically and will be heading to the surface. If you only have 10 feet of vis and can’t see your buddy, you won’t take the time to look. Even if they do swim to their buddy, it won’t be a casual swim over, get their attention, give them the OOA signal, and wait for a regulator. Chances are they are going to swim straight into their dive buddy and grab whatever air source is the closest. Most likely their buddies primary reg.
Again, I am not advocating one way or the other, simply pointing out that while the failure can happen, in all likelihood it won’t but some still feel the need to address this remote possibility by carrying an independent secondary system. Again, carrying it and effectively deploying it in an emergency are two different things. While both sides can support their position, it comes down to personal choice and what makes you feel more comfortable in the water. I approach this from a paradigm of decades as a PSD where I dove with backups for my backups. I always dive with redundancy as I prefer to rely on myself to get out of trouble rather than another diver. While this is my philosophy, it may not be desirable for others. I don’t think adding a pony to a novice diver is that difficult as long as they know how, when, and why it is utilized.
My only argument against a pony is in its use in case you run your main cylinder(s) too low to complete the dive. While I have heard people say they ran out of air and used their buddy to complete the dive, I find this type of dive “planning” totally unacceptable. Fortunately, I have never dove with anyone that simply ran out of air. The people I dive with do not take diving lightly and approach it with the respect it deserves. If I have to dive with folks I don’t know, I will periodically do air checks to see how consumption is going. Fortunately, most divers with lackadaisical approaches to diving tend to congregate so they can generally share their misery together.
An OOA scenario at 100 feet and your dive buddy is 30 feet away looking at something else besides you can create all kinds of drama. The logical action would be to swim the 30 feet to the buddy versus the 100 feet to the surface but I would argue that the average panicked diver in this type of situation will not respond logically and will be heading to the surface. If you only have 10 feet of vis and can’t see your buddy, you won’t take the time to look. Even if they do swim to their buddy, it won’t be a casual swim over, get their attention, give them the OOA signal, and wait for a regulator. Chances are they are going to swim straight into their dive buddy and grab whatever air source is the closest. Most likely their buddies primary reg.
Again, I am not advocating one way or the other, simply pointing out that while the failure can happen, in all likelihood it won’t but some still feel the need to address this remote possibility by carrying an independent secondary system. Again, carrying it and effectively deploying it in an emergency are two different things. While both sides can support their position, it comes down to personal choice and what makes you feel more comfortable in the water. I approach this from a paradigm of decades as a PSD where I dove with backups for my backups. I always dive with redundancy as I prefer to rely on myself to get out of trouble rather than another diver. While this is my philosophy, it may not be desirable for others. I don’t think adding a pony to a novice diver is that difficult as long as they know how, when, and why it is utilized.
My only argument against a pony is in its use in case you run your main cylinder(s) too low to complete the dive. While I have heard people say they ran out of air and used their buddy to complete the dive, I find this type of dive “planning” totally unacceptable. Fortunately, I have never dove with anyone that simply ran out of air. The people I dive with do not take diving lightly and approach it with the respect it deserves. If I have to dive with folks I don’t know, I will periodically do air checks to see how consumption is going. Fortunately, most divers with lackadaisical approaches to diving tend to congregate so they can generally share their misery together.