CESA from 100 feet?

[pete340]

This is just an example so don’t get upset about the depths or exact figures. You could most likely get away with holding a full breath of air from 600’ to 400’ without any problems. But holding that same volume of air from 15’ to the surface would most likely kill you.

Sorry, but the numbers do matter. 600' to 400' is about a 1/3 reduction in pressure. 15' to the surface is also about a 1/3 reduction in pressure. Both are equally dangerous.

 

[jepuskar]

Gary,

Are you saying that the air in your lungs won't expand between 600' and 400'?

You're kidding right?

 

[Gary D.]

Gary,

Are you saying that the air in your lungs won't expand between 600' and 400'?

You're kidding right?

Here we go with exact numbers. I said don't pay attebtion to the numbers, but now that it has started we have 200' of change being equal to 15 feet of change.
That is all I was refering to WITHOUT using exact numbers.

The volume changes are much greater per foot the closer you get to the surface so there is less room for error in shallow water. People think it's safer in shallow water but that isn't always the case.

Gary D.

 

[Grajan]

I hope this important point is not lost in the search for precision. It bothers me that this critical skill is taught so poorly and that it is taught to the surface from the get go.

I believe that it is considerably safer to practice this with short ascents from depth before trying to reach the surface. The last 30' is the major risk.

Here we go with exact numbers. I said don't pay attebtion to the numbers, but now that it has started we have 200' of change being equal to 15 feet of change.
That is all I was refering to WITHOUT using exact numbers.

The volume changes are much greater per foot the closer you get to the surface so there is less room for error in shallow water. People think it's safer in shallow water but that isn't always the case.

Gary D.

 

[pete340]

I hope this important point is not lost in the search for precision. It bothers me that this critical skill is taught so poorly and that it is taught to the surface from the get go.

I believe that it is considerably safer to practice this with short ascents from depth before trying to reach the surface. The last 30' is the major risk.

Good point. Ascending from 100' to 70' is safer than ascending the same distance from 30' to 0'. Those are much better numbers than the original ones.

 

[Gary D.]

Good point. Ascending from 100' to 70' is safer than ascending the same distance from 30' to 0'. Those are much better numbers than the original ones.

Bingo to both of you. That is exactly what I'm saying WITHOUT exact numbers which I put in a disclaimer for at the start of my post.

Gary D.

 

[Randy43068]

SETT (Submarine escape tower in the UK) is 30m (100ft) deep.

..and yes you can dive it when its not used for training too

Hey string, what's all that "stuff" hanging offa you in your picture? Man, you've got every gadget known, don't you?

 

[String]

Hey string, what's all that "stuff" hanging offa you in your picture? Man, you've got every gadget known, don't you?

DSMB/Reel (needed on every dive)
Torch (needed on most dives)

and err thats it i think!

Edit:- a camera which i rarely take on UK diving due to the vis.


The only other stuff i can see is my strobe (cable tied to inflator hose) and storm whistle (attached to inflator also).

Necklaced reg is my pony reg. Dangling contents gauge due to clip snapping (i didnt like a 15l cylinder being dropped on it pre dive)

 

[Randy43068]

DSMB/Reel (needed on every dive)
Torch (needed on most dives)

and err thats it i think!

Edit:- a camera which i rarely take on UK diving due to the vis.


The only other stuff i can see is my strobe (cable tied to inflator hose) and storm whistle (attached to inflator also).

Necklaced reg is my pony reg. Dangling contents gauge due to clip snapping (i didnt like a 15l cylinder being dropped on it pre dive)

picking on ya...

 

[String]

CO2 is defiately the first reflex trigger (im not at home with access to my old uni medical textx now to quote though) and its the main reason shallow water blackout happens.

Oh and for the record, ive never done a free ascent (or CESA as padi call it) for real and never taught or trained one either