One of the most common errors I witness as an Instructor is calculating the correct Total Bottom Time on the Recreational Dive Planner. The failure to add Residual Nitrogen Times to the Actual Bottom Time leaves the diver with an increasing accumulation of nitrogen in the body.

Why is this a problem?

It exposes the diver to the possibilities of Decompression Illness which could lead to serious harm to the diver.

Why is calculating Total Bottom Time important?

In order to minimize inadvertently and unknowingly augmenting residual nitrogen over the course of repetitive dives, the diver must be conscious of the residual nitrogen retained in the body after a period of surface interval and account for the residual nitrogen by factoring it into their Actual Bottom Time. Failure to account for the residual nitrogen results with the diver being at an increase risk of Decompression Sickness or Decompression Illness due to …