Well Dave, in Navy diving ops there is a "standby diver" who in hardhat
diving is completely dressed with exception of the helmet, which takes all
of, let's say 5 seconds to don.
The stay time may have been longer if the suit were fully inflated. Anyone
that has dove the Mk 5 can tell you that if the suit (or any dry suit with
an air fill) is fully inflated, the diver will be wriggling around on the
surface bobbing like a cork.
The o2 starts at 21% and when it drops to 16% the diver starts to experience
hypercapnia AND hypoxia.
The rig was designed to sustain life underwater. Attaching the hose with a
nut was the highest tech option they had at the time.
MMC
"Dave" wrote in message
...
On Wed, 26 Apr 2006 13:41:50 GMT, "MMC" said:

As I remember a Mk 5 diver would be conscious for something like 6
minutes
if he lost his air supply

My recollection is that it would be significantly more than that.
Remember,
we're talking about the time required to reduce the percentage of oxygen
in
the fixed amount of air contained in the suit and hat combined to below a
level that will sustain life. The rig was designed so the if the air hose
where cut completely you could send another diver down with a new hose and
hook it up to the hat. I'd be surprised if that could be done in under 6
minutes except in the most exceptional circumstances.