deep diving

Question
QUESTION: Dear James,
In standard scuba gear, with standard tanks and air supply,
how deep could a diver go and come back without problems. I
believe this is a time issue so if time is minimized could
someone go deeper safely. If so, how deep and what are the
time constraints? thanks
Sincerely, Dick Schlueter


ANSWER: Hi Richard,

Is this a theoretical question, or a practical question of how deeply can one safely dive with standard gear?

saludos,
James

---------- FOLLOW-UP ----------

QUESTION: it is a theoretical for a book that I am writing, thanks ds...

Answer
Then I would look into HPNS (Google it) but that is based on using deep diving equipment, which at least would include a special mix of air and additional cylinders ("tanks"), but you could do it with "standard" scuba equipment, you would just need training.

For someone just grabbing some gear and heading down, google nitrogen narcosis, which will be the limiting factor for anyone attempting to perform any tasks under water.  It can be quite debilitating to the unaccustomed.

Finally, if we aren't concerned with tasks, there is a point where, due to increased pressure, the oxygen in air becomes toxic.  http://en.wikipedia.org/wiki/Oxygen_toxicity#Underwater

For air, going below about 80m can provoke different reactions in some people, including convulsions.  Air is not a good gas for deep diving.

A really good summary for you is this: http://en.wikipedia.org/wiki/Deep_diving

So, that info should help you put the limitations into use based on the context of your book.

Let me know if you have any other questions, and good luck with that.  Please take a moment to complete the evaluation of your response.

Saludos,
James