Posted by Bill Johnson on April 16, 2000 at 09:03:25:
In Reply to: A 'Tech Dive' posted by Bill Johnson on April 16, 2000 at 08:52:37:
...less than 21% oxygen, dives in an overhead environment beyond a visible exit or dives requiring staged decompression ceilings greater than 20' or greater than 10 min.
Regards,
Bill