In dive, manage having EAN programed into computer while diving air?

[tbone1004]

I'm not going to say that this is the correct thing to do & I'm not going to recommend that other people do this, but what I would have done in that situation is slowly ascend to 30' & hang out there until I had 500psi left in the tank, then ascend to 15' & hang out there until I had 200psi, then surface slowly & immediately let me buddies know that I goofed up & ask them to keep an eye on me while I look to see if the oxygen bottle on the boat is full or not.

why stop at 30ft?

 

[PBcatfish]

why stop at 30ft?

I was going to not go into details of my personal opinions that are not backed up with book references, but since you asked, I will give you an honest answer. I will also preface this answer by restating that I am not saying this is the correct thing to do, nor am I recommending it to other people.

30' a good pre-deco depth from my experience. When I spend time there, I see my deco time requirement bleed down on my computer. My personal opinion is that getting rid of some dissolved gas there makes things easier on your body when you then go up to 15'.

When I have followed an approved profile perfectly, but run it to the edge, I have often come up with a slight headache. When I lollygag around 30' on the way up & then do a proper safety stop, I generally feel better after surfacing. I don't like to push my luck, so I tend to take it easy on the way up. I also tend to carry a fat air reserve.

If I find myself with a flooded computer, or in some other situation where I do not know my proper deco time, I will make an effort to do maximum deco with my available air supply. That is my basic strategy. But again, that's just me. I'm not a professor on the subject & I'm not going to pretend to be one.

 

[tbone1004]

@PBcatfish why not just do it all at 20ft? It's quite interesting to see that, since in decompression diving we don't use 15ft as a stop depth. 20ft, 10ft if you can depending on the environment, then surface.

 

[PBcatfish]

@PBcatfish why not just do it all at 20ft? It's quite interesting to see that, since in decompression diving we don't use 15ft as a stop depth. 20ft, 10ft if you can depending on the environment, then surface.

15' is where my computer normally sends me for my safety stop. that is why I picked 15' for my final stop.

I prefer progressive stops, since watching bubbles form in a coke bottle seem less aggressive when you let the pressure out in small steps.

If I had an actual ascent program to follow, I would follow it. This situation is a case where I do not have correct info to follow & I am winging it.

Again, I am not saying that my way is the correct way. It is what I would have done if I found myself in that sort of oops situation with no reference available & only my common sense to guide me. If I were to research a proper procedure, I would likely come up with a better answer.

 

[tursiops]

If I were to research a proper procedure, I would likely come up with a better answer.

Might be worth the effort......

 

[John C. Ratliff]

Great discussion. I learned a lot.

SeaRat

 

[PfcAJ]

This is why im always on about knowing the tables and planning your dive.

 

[BoltSnap]

This is why im always on about knowing the tables and planning your dive.

Tables have nothing to do with this at all, it is about paying attention to your equipment and establishing a routine/habit/check list that includes verifying your computer's settings.

 

[UCFKnightDiver]

@HKGuns functionally impossible. We have enough issues measuring ppO2 at ambient pressures, to try to measure it at 300bar/4500psi is not possible with todays technology, nor do I see it being useful for any non diving application

What is your thought process behind it being functionally impossible? In open circuit, your percentage of oxygen doesn't change, so if the computer knows your depth and the ppO2 of the gas, then it should be simple to calculate the percentage of oxygen in the mixture. If high pressure is the issue, could you locate the sensors on the LP side of the reg? I do agree you're adding a lot of issues with likely needing multiple o2 censors, etc, but I think it's certainly possible to design a system to do this if someone was so inclined.

By the way, I'm not arguing that this is a good idea, just thinking critically about the possibility of the idea.

 

[tbone1004]

What is your thought process behind it being functionally impossible? In open circuit, your percentage of oxygen doesn't change, so if the computer knows your depth and the ppO2 of the gas, then it should be simple to calculate the percentage of oxygen in the mixture. If high pressure is the issue, could you locate the sensors on the LP side of the reg? I do agree you're adding a lot of issues with likely needing multiple o2 censors, etc, but I think it's certainly possible to design a system to do this if someone was so inclined.

By the way, I'm not arguing that this is a good idea, just thinking critically about the possibility of the idea.

The LP side of the reg is still at call it 10bar at the surface, so where we have O2 sensors that can measure ppO2 of up to 2.0 mostly reliably, you'd have to design one that could measure a ppO2 of 20. Still no real practical reason to develop that outside of this application that I'm aware of which means it would be nearly impossible to get it developed.