Deco stops

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TwoBitTxn thought I once bubbled...
I always stuck to the 1.4 rule on the bulk of the dive but switched to 1.6 for deco to utilize 100% O2 as there little risk involved and deco is much shorter with 100% oxygen since there is no nitrogen counterpressure.
CNS oxtox is a random event above a ppO2 of 1 bar but can be lessened by relative hyperventilation. It is assumed a diver is largely at rest during deco although Dr Deco recommends cyclical finning at stops to maintain effective tissue perfusion and maximum off-gassing.
Saturation once bubbled
. . . If we take circulation time as a factor to reduce the total 02 time. . .
I am not sure this makes sense. If it takes a certain time for equalisation at the start of any gas change it takes the same time for equalisation at the end of that change. Surely this is just swings and roundabouts since what is taken away at the start must be added at the end?

However, Saturation, I entirely agree, I think!

Take Home Message:

Take the 02 breaks to lessen whole body toxcity, add the break time to your 02 time


Here I go, showing my ignorance again. What's a decoweenie. (Indeed what's a weenie?)
 
Dr Paul Thomas once bubbled...
Here I go, showing my ignorance again. What's a decoweenie. (Indeed what's a weenie?)

A decoweenie is someone who does needlessly long deco stops.

A weenie is, well, a weenie :)

WW
 
What would you say to the argument that a jon line is a safety device against oxtox at the 20' stop because it tethers you to the anchor line where your buddies can get to you and help you to the surface?
 
In the decompression phase, being rested and shallow is key to tolerating a pp02 of 1.6 ATA, even as high as 1.9 ATA. The limit of 1.3 is used as a bottom mix, i.e., backgas or pp02 of your main tanks, its presumed some exertion will be involved swimming at depth. Its probably better to limit bottom mix pp02 to 1.2

A reason for tolerating the higher pp02 at the shallows is a reduced risk of retaining c02: gases are less dense and easier to breath. Issues with 'easy breathing' regulators are less critical.

Not exerting onself is very important to avoid generating more C02 and other factors associated with convulsions, such as andrenaline release.

Exertion means any of the following: feel winded, can't catch your breath, pulse rate over 100 bpm, or respiratory rate over 16. If your baseline in-water pulse and respiratory rate is already as above, diver is probably out of shape to begin with. You'll need to slow down or lower your pp02 exposure.
 
O-ring once bubbled...
What would you say to the argument that a jon line is a safety device against oxtox at the 20' stop because it tethers you to the anchor line where your buddies can get to you and help you to the surface?
Hi O-ring,

Safety device, yes. . . . . :confused:
 
O-ring once bubbled...
What would you say to the argument that a jon line is a safety device against oxtox at the 20' stop because it tethers you to the anchor line where your buddies can get to you and help you to the surface?

I'd say it's at least somewhat valid, if a bit convoluted :)

WW
 
Dr Paul Thomas once bubbled...
Hi O-ring,

Safety device, yes. . . . . :confused:
The only reason I mention it is we got in a conversation about this recently and were talking about this in the context of a pretty ripping current. The example was something like, "man, if you toxed at 20' today, you would be gone and we would never see you again"..."well, not if I had a jonline"..
 
O-ring once bubbled...

The only reason I mention it is we got in a conversation about this recently and were talking about this in the context of a pretty ripping current. The example was something like, "man, if you toxed at 20' today, you would be gone and we would never see you again"..."well, not if I had a jonline"..

Its a good point. I never thought of it that way but it certainly works. It does assume the jonline is clipped to you, not just held though.

WW

ps- You know of course that jonlines have been pronounced as "for strokes"?
 
Just a question, is it recommended to make a deco dive in such condition, strong current and low viz, what for . at least when u want to do a dive and u want to enjoy it u have to be in better condition and if not u will know the risk u are into. Anyway
 
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