better look here for the proper numbers:
http://www.americascup.com/en/actualite/twitter/
with these numbers you can understand the postponement.
There is a lot of noise and wrong numbers around at the moment. Heard also somewhere that last Wednesday the wave height was rather 1-2m instead of 1.2m.
As usual, you can't judge the weather conditions if you aren't there (right on the water).

Cheers,

Klaus