I haven't used tables for 20 years since I aquired a reliable dive computer. However the original tables that were widely used (French Naval) used to give unlimited time at less than 40 foot. The arguemant being that at some point the partial pressure is insufficient to drive nitrogen into suspension in the blood stream. That limit was 1.25bar (relative) or 2.25 bar (absolute) or about 40 foot.
Since then advances in medical understanding including absorbtion into multiple tissue types has lowered almost year on year the limits of no-stop diving. There is also no small element of risk avoidance and litergation in the newer figures. 60 minutes at 60 foot was the easily remembered benchmark. My Suunto now only gives me 53 minutes at 60ft.
Maybe the safe absolute no-stop limit is now 30 foot, but 40 foot is still going to be reasonable.
If in doubt ... be safe.
Good luck.
Dave
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Born to fish. Forced to work.
Last edited by Old Man Dave; April 28th, 2008 at 22:21.
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