Jerome Meekings wrote:
David G. Nagel wrote:

Jerome;

What Fred was talking about is that O2 at one atmosphere and 100%
concentration is toxic. This is why the maximum depth for scuba divers
using standard air mix is 300 feet. The partial pressure of atmospheric
oxygen is 14.7 pounds per square inch at that depth. This is the
equivalent of 100% concentration at sea level.

That was the one we were talking about, though I don't think Fred got
the point that it was one component not both.

And the usual limit for most scuba divers is 130 feet or 40 Meters, not
91 Meters 300 feet. For that it is usual to have a 3rd gas "He" in the
mix.

But that is getting too complex and loosing the point of the joke.

Jerome;

The practical depth for nonprofessional scuba divers is about 100-150
feet as you say. This has more to do with the ability to handle the
depth than anything else. The MAX depth for any diver using O2-N2 mix is
300 feet period. At that depth the partial pressure of O2 is 14.7 pounds
per square inch which is lethal.

Dave