joker97: if they knew there was a decompression they should
1) take a big breath and hold for as long as possible .....
don't you reckon?
No. Why?
You are missing the point. Normal depressurisation procedure is to don the O2 masks and breathe normally. They wouldn't know there was no O2 supply in this case.
The depressurisation will cause the air in the lungs to be expelled rapidly, besides taking a big breathe of nothing (well nearly nothing and certainly no where enough O2) isn't going to stop you from losing consciousness very rapidly.

