# Stepped off-gassing

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Posted by Eins on December 04, 2000 at 17:30:31:

In Reply to: Re: Safety Stops posted by MHK on December 04, 2000 at 14:30:21:

OK, so I'm not really educated about all the models and algorithms ever devised, but here is my stab at this problem, using logic and as much intelligence as I can muster up.
I'm trying to express myself as well as I can in this language.

As you are descending to the deepest point of your profile, your tissues are in-gassing under increasing pressures. Had you stopped 5 feet above your acutal deepest point, your tissues would not have gotten the last 5ft delta, etc. This means, there is a gradient of deltas that you added to the already existing degree of saturation.

If my thinking is correct so far, then reversing this process should produce reversed results:

A slow ascent allows the highest in-gassed delta to slowly off-gass under an ambient pressure that has decreased less than it would have at a faster or no-stop ascent, therefore allowing it to create less bubble potential as the diver's depth = pressure decreases. So, for the highest delta, a slow ascent appears to be beneficial.

Now, a slow ascent also means longer "bottom" times for the shallower deltas, which means more in-gassing for the diver. However, this takes place at shallower depths, which means, less pressure difference-to-surface than the deeper depths. And again, a slow ascent (or deep stops) allow the deeper-pressure deltas to off-gass before the bubbles can reach a critical size.

And so on.

This model anticipates that the total ascent time must be longer to take advantage of the stepped off-gassing. However, considering the inherent risk of deep diving, this may well be worth it and reduce the number of unexpected or undeserved hits.

So, what do you think?

Eins

PS: Algoreithm = Continued calculations, until the desired result is achieved

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