On 22 September 1999 22:57, Kuty wrote:
 
> At 09:40 22/09/99 +1000, Strike wrote:
>
> >On 22 September 1999 00:05, Carl G. Heinzl, wrote:
>
> >>Remember - a long time ago a PPO2 of 3 ATA was the
> >>accepted limit - then it went down to 2 ATA,
>
> >I don't remember that! (The WWII experiments established a
> >maximum PPO2 of 2 ATA's for in-water use that remained a
> >'standard' for thirty-plus years! ) :-)
>
> That's what I recall too. BTW, this is the reason for the 10 meters depth
> limit for pure O2 rebreather diving in some navy units (according to
rumors).
 
I don't know about rumours <BWG> but it's the reason the RN placed a
limiting depth on O2 units! (And consider, of course, that sailors are more
expendable than the cost of a warship, so operationally it is/was exceeded
in times of 'dire need'!) :-)
 
> >>now the (almost universally) accepted limit for the working
> >>part of a dive is 1.4 PPO2 (1.6 PPO2 for deco).
>
> Strike, do you know if the navies modified O2 rebreather diving according
> to the 1.4, 1.6 values?
 
It dropped to 1.6 after US Navy studies and then lower. I believe the US
Navy now have a set-point of 1.3! And I'll repeat what I said some time
last year to a similar post - I bet it'll be dropped to 1.1 within the next
few years! :-)
 
Strike