Now I wish I had access to an olympic pool. For my first C card (12years old), I had to swim under water with fins and mask a full lap (164ft X 2) without coming up. I was actually able to swim that lap plus almost another length. Blew away the adults in the class. Huge lungs and skinny as a rail. Not much muscle to support. I could only do it once though. Doing it twenty times with minimal rest would be a biotch.
I did learn to see those stars and to come up quickly.
Now I only see the stars when I get bashed in the face. :proud:.
One thing though. I also found that using my arms for forward strokes only wasted my air and caused me to lose momentum. Keeping my arms at my sides and using wide fin strokes was the way to go.
Eugene, did you ever experiment with moving your chest muscles around in an attempt to swirl the air around in your lungs in hopes of finding a few more O2 molecules? I did. Couldn't say whether it helped or not though.