Diving 32% Nitrox with "Air" Algorithms

[arew+4]

Hypothetical!!!!

I follow the one drink per hour rule and leave bar after four hours but s-faced I was drinking Russian imperial stouts at 9.5%.

Fix number one continue to drink the same beer, but change the model to one every two hours.

Fix number two, drink some pale pseudo stout (Guinness) at 4% and stick with model

 

[tursiops]

Hypothetical!!!!

I follow the one drink per hour rule and leave bar after four hours but s-faced I was drinking Russian imperial stouts at 9.5%.

Fix number one continue to drink the same beer, but one every two hours.

Fix number two: recognize that the "one drink per hour rule" is based on 1 1/4 oz of hard liquor per hour, and drinking 9.5% beer violates that rule. So it has nothing to do with individual physiological variability, and all to do with using a rule that is inapplicable.

 

[arew+4]

Fix number two: recognize that the "one drink per hour rule" is based on 1 1/4 oz of hard liquor per hour, and drinking 9.5% beer violates that rule. So it has nothing to do with individual physiological variability, and all to do with using a rule that is inapplicable.

Just presenting two different ways to solve a similar problem.
Suppose your ability to process alcohol has declined with age and your metabolism no longer allowed you to consume 1 beer per hour at 5%. You could slow down or switch to light beer at 3.5% and not need to modify your behavior.

 

[tursiops]

Just presenting two different ways to solve a similar problem.
Suppose your ability to process alcohol has declined with age and your metabolism no longer allowed you to consume 1 beer per hour at 5%. You could slow down or switch to light beer at 3.5% and not need to modify your behavior.

LOL. Switching to light beer is not a solution to anything!

 

[L13]

So where is the lack of wisdom in his approach, and do not say you shouldn't lie to your computer. Conservatism adjustments are arbitrary modifications to the calculations, either adjusting a variable or a bounding condition. Also lying to the computer.

Are you saying that dive computer manufacturers arbitrarily modify their algorithms without at least a little expert attempt to implement it rationally?

 

[arew+4]

Are you saying that dive computer manufacturers arbitrarily modify their algorithms without at least a little expert attempt to implement it rationally?

Where did you get that from. Telling your computer you are at 3000' above sea level is arbitrarily modifying a variable.
And it does not take into account any physiological difference specific to the driver that may have caused DCS in the first place.

 

[Cheizz]

"I'll just adjust the variables in the system - as long as I don't need to change my behavior!"

This sounds unwise, though very human indeed. But if your behavior (i.e. staying under longer/deeper) is a risk, there ultimately is no other way to mitigate that risk than to change your behavior.

 

[arew+4]

LOL. Switching to light beer is not a solution to anything!

While I do agree with statement I had to use the example to make my case.

 

[L13]

Where did you get that from. Telling your computer you are at 3000' above sea level is arbitrarily modifying a variable.
And it does not take into account any physiological difference specific to the driver that may have caused DCS in the first place.

1) Only some, now very old, computers implemented conservativeness this way.

2) For most if not all widely used algorithms, changing the surface altitude changes the algorithm results in a very different way than changing the O2 fraction. Presumably in a way that works better, based on the expert opinion of the computer manufacturer, to introduce conservativeness.

 

[Belzelbub]

Conservatism adjustments are arbitrary modifications to the calculations, either adjusting a variable or a bounding condition. Also lying to the computer.

Depends on the computer. I do agree that adjusting the conservatism on a computer where the algorithm is not published is arbitrary, or at least could be. For others though, I wouldn't say that it's arbitrary. It's adding a buffer between the computer calculated saturation and the theoretical maximum value.

By not inputting the correct gas mix, you might be doing the same thing, but you aren't tracking O2 correctly. Might not be a problem for most divers, but I would say that depends on the plan.

I look at it this way. One of the main benefits of diving with a computer is that you have real-time guidance throughout the dive. The guidance is only as good as the information you feed it. Yeah, you could feed it bad information to add a safety buffer, but for the most part, it's just not necessary. Many different ways to get to the same goal.

I can input a higher N2 content than I'm actually breathing. I can adjust a safety buffer. I could even leave both of those alone and just head up before NDL reaches X, or determine a SurfGF value to end a safety stop. All of those could help. I just find it a bad practice to input an incorrect gas when other options exist.