need Nitrox 32 info...

[Spectre]

I really hate to side with NOVA, but I think I need to here. Most of you guys are missing what he's saying. It's very difficult to plan a dive based on pressure. Think about it, what are tables given in? You don't see PADI publishing PSI tables. What's the NDL for 60 ft, is it a time or a pressure?

Ya know corney... I think I can avoid agreeing with Nova by just agreeing with you

Here's the gist. Those that dive with pressure aren't really just diving pressure, they -are- diving pressure and time... it's just that in general context you're hitting your pressure before your time. What you have done is calculated out your pressure based on the time it is going to take for your ascent, so you have enough gas remaining to make that ascent.

But that gas you will use to actually -make- the ascent is a fixure of time. It will take X amount of time to make that ascent provided you stay within your time window. Basically "If I dive to 100 feet for up to 20 minutes, it'll take me 7 minutes for my ascent and that's 600 psi". So the "ascend at 600 psi" part is -based- on staying within 20 minutes. The clock is really whats ruling it.

What Nova is trying to point out is that if you take that "for up to 20 minutes" out of the equation... now you throw the "600 psi is enough to get to the surface" out, because the time of ascent grows longer as the bottom time grows longer.

So yes... it's all about the clock. The clock determines the PSI reserve required. If you exceed that bottom time clock, you just through the ascent time clock that was used to calculate the necessary reserve PSI right out the window.

 

[Jason B]

what's MORE critical Jason? time ? or presure ?

My money's on Time

If I exceed time, I may get bent, if I exceed pressure (in an overhead as that is where my example was) I may go home in a body bag.


Hey nova, I thought they cleaned house here a few months back .

 

[Spectre]

... nevermind...

 

[Jason B]

Huh? Lost me on that question.

EDIT- I see you retracted said question. nevermind here too

 

[Jason B]

Most of you guys are missing what he's saying. It's very difficult to plan a dive based on pressure. Think about it, what are tables given in? You don't see PADI publishing PSI tables. What's the NDL for 60 ft, is it a time or a pressure?

I see what you are getting at and I do agree with your above statement.

 

[nova]

If I exceed time, I may get bent, if I exceed pressure (in an overhead as that is where my example was) I may go home in a body bag.


Hey nova, I thought they cleaned house here a few months back .

for one, if you exceed pressure, then you cut into your extra third. If you exceed time , then you cut into your extra third at the same time your buddy cuts cuts into theirs (because your both in deco)


and yes, they did clean house, but their all on dive trips so they don't know I'm back.

P.S have fun with Johnny in intro, hope all goes well

 

[Jason B]

Shhhh, I won't tell.

Thanks for the kind words.

Jason

 

[Mirjana]

Hence turning to the gas in time )))

I've recently learnt that these things have to be learnt over and over again. It's like with the multiplication tables that one learn as a child.....Once you adopt them, you get able to go further....

In short, yes. Excluding contingencies situations. (More exertion, more current, equipment failures etc).

A properly planned dive will have ample gas to complete the planned dive time. Contingency planning is where you account for the unknown's that may lead you to increase you air consumption from your planned dive. (Hence, then turning on gas not time)

Mike