The Computer Between the Ears

[tarponchik]

...because no one has ever gotten bent when not using a computer, right?

I did not disclose the reasons for asking the question, but no.

 

[NAM001]

Pattern recognition.

It is quite possible to train your subconscious to recognize ascent patterns for various dive profiles, you just have to dive a lot. Then you could express them as, say, ratios. But while you're training it, ascents have to be calculated by some other computer.

And then you've trained your brain to follow whichever model that dive planner was using. So if you used the one that generates deeper stops, your brain now wants to make deeper stops. If that is no longer advisable -- re-training the brain takes forever and the older we get, the harder it gets.

There might be a human out there capable of keeping track of 16 tissue compartments simultaneously in his head, but I'm sure most of us are not him. Brain is not running the same model and all those comparisons to computers are bit of apples to Pink Floyd.

Fortunately for rec diving the compartment issue is not a factor other than the first one, and that is covered by the single factor of NDL. Rec diving was designed to be kept simple with minimal risk so that dummys can do it.

 

[dmaziuk]

Fortunately for rec diving the compartment issue is not a factor other than the first one,

Would that be the 4-minute compound, or the leading compound, and are those one and the same on my 25th Al80 in a 7-day period? Enquiring dummies want to know.

 

[NAM001]

Would that be the 4-minute compound, or the leading compound, and are those one and the same on my 25th Al80 in a 7-day period? Enquiring dummies want to know.

Im not sure what you are getting at. All the rec diver is concerned about is the 1st compartment because rec diving is not deco diving. If other than the first is involved and a concernable factor, you have left the rec arena.

 

[KevinNM]

Im not sure what you are getting at. All the rec diver is concerned about is the 1st compartment because rec diving is not deco diving. If other than the first is involved and a concernable factor, you have left the rec arena.

The first compartment is 4 minutes. I often do NDL dives longer then that.

 

[NAM001]

The first compartment is 4 minutes. I often do NDL dives longer then that.

Is that not a 4 minute half time 100 ft gives a NDL of about 20 min..... that would be about 5 half times till ndl.

 

[wetb4igetinthewater]

Long time ago I've asked here a question, if there was actually a proof that comps make diving safer and I was condemned as a troll (which, of course, I am). However, regardless of my trolling, the March issue of Scuba Diving had a story (pp 32-3) of how a diver got DCS while following his comp guidelines. Makes me wonder...

We cannot forget that the models are just that: models. There is a certain level of confidence that by following an algorithm, there is a certain probability that one will not get bent. Conversely, there is a certain probability that someone will get bent as well. Was is the person well hydrated? Well rested? What was the person's fitness level at the time? What is their age? Did they dive in a zig zag pattern or a monotonic ascent/descent?

 

[wetb4igetinthewater]

What I find funniest about these "debates" is the seeming belief many show that it can only be 100% one way or the other. In the real world it isn't all about absolutes, there is a lot of middle ground and overlap.

That's why I pointed out with Shearwater (and probably others) you can have the total dive time to conduct on the fly deco calculations and also have the backup algorithm. I'm not sure if I'll take further training through a DIR agency. I suspect I'd have to hide my extra Shearwater that wouldn't be in gauge mode in a pocket.

 

[KevinNM]

That's why I pointed out with Shearwater (and probably others) you can have the total dive time to conduct on the fly deco calculations and also have the backup algorithm. I'm not sure if I'll take further training through a DIR agency. I suspect I'd have to hide my extra Shearwater that wouldn't be in gauge mode in a pocket.

You have it show the stopwatch and average depth while in tech mode.

 

[boulderjohn]

Is that not a 4 minute half time 100 ft gives a NDL of about 20 min..... that would be about 5 half times till ndl.

Recreational dive algorithms are not just based on the fastest compartment. If you go to any of them with dive logs that show the compartments leading the dives, and you will see that they change as the diver progresses through the dive.