I think that during my AOWD course finally met together a few skills I intentionally and unintentionally learned in my life. It comes from self-consciousness issues, self-observation, lifestyle and that I learned meditation many years ago. Maybe my physiology has something to say in this case. At the beginning of August 2018 my weight was 85 kg. So I lost about 7 kg of my weight compared to the period when I lived in Warsaw.
As we can see physiological standard for complete rest for 70 kg person is 7,5 liters per minute.
And when we transform how much it means at 18-22 meters below surface we should multiply 7,5 approx. 3 times what means 22,5 liters per minute as a standard for rest.
Taking into account that my breathing rate on 18-22 meters measured by tank air consumption resulted in 20 liters per minute air consumption converted to a surface rate means that I settle on lower level of the range known for humans. During exhaust breathing rate can increase in terms of many times more liters per minute. It is highly individual but I have read even about hypothetical rates like 300 liters per minute on a specific depth what simply means much. I treat it as a skill for me because I used to be short in air at the beginning of that adventure in my life and diving to 8 meters and being about 40 minutes could result in being short in air compared to my last dive in August when I reached 32 meters below sea level and have spent 47 minutes underwater total and my manometer did not reach finally even 50 bar what means usually minimum that when we notice we always start the procedure of ascending. It allows to stop for approx. 3 minutes but when we started to ascend from 10 or 20 or even 25 at 18 meters per minute rate of ascending and even stop for 3 minutes when we did it before 50 bar on manometer limit it is usually safe. When you realize that my last dangerous dive in 2009 was the situation when I realized to have 50 bar at 20 meters underwater and it was the moment I saw my buddy swimming into the wreck. This means I did not have even minutes for a decision. I was waiting for some time anyway. But my decision to ascend should be immediate that time. With that certificate, skills and experience. Now my skills are a bit fine-tuned. But the deeper you go the more interdependent you become with your buddy. Who is breathing less efficiently determine generally how long, how safe is dive. And sets limits for whole adventure.
I mean my rate was 20 converted to surface rate. So it is not exactly like for rest. But it isn’t also a rate for exhaust. But diving to 18, 20 or more actually is an exhaust due to nitrogen, stress, many more variables to control than we normally are used to on the surface in one time. We do things in minutes, hours, days. Underwater we are usually limited to magical 50 minutes when it refers to recreational diving with 15 or 12 liters tank.
My notes from Jacques Mayol book Homo delphinus: