Again, very insightful. The recurring theme throughout these replies is that all of the tables are based on "safe theory" that has been in place for years. The overall result as MuckDiver points out is that it's a few minutes one way or the other. New algorithms and numbers of "tissue types" (simply an estimated rate of absorbtion/off-gassing at a given depth) are being developed and tested. Varying rates of ascent and air integration have also been used to determine a closer look at the gasses absorbed on a particular dive profile. As technology moves forward, we will see even more ways of monitoring the gasses absorbed on a dive.