hi
I have kept records of my FVC since I did my first Scuba diving medical back in 2000 I had a FVC recorded back then of 4.8L. I did a lot of pack stretching throughout 2002 but did not get a medical done in that year. In 2003 I did a small amount of pack stretching and packing but only minimal comapred to 2002, at the very end of 2003-2004 I had a series of FVC tests done over roughly a month The "best" FVC I have had recorded is 7.53L these were all done on the same machine however you can say I cheated for the 7.53L test becasue I did quite a bit of Max packing and pack stretching before I went into the Doc to see how far I could go.
However in another thread a guy said that showed through his results that there was a big difference between a FVC reading and a VC reading so I don't know what my VC is probably significantly less than 7.53L FVC
