* Bob wrote, On 3/3/2007 12:38 AM:
....
But I am sure I have read somewhere that wave height, like the amplitude of
a sound or radio wave, is measured from the average to the extreme. This
would result in a value of one half what is commonly stated. This causes me
to pause when someone asks "how high are the waves ?".

Has anyone else heard of wave height measured this way ?


Crest to trough = wave heigth
but the stinker is when we hear or read the "marine forcast" and it
mentions wave heigth. I that measurment is a mean or average
calculation of what?

This is why I posted the definition directly from the NOAA web site:

"the average height (trough to crest) of the one-third highest waves
valid for the indicated period."

For a full explanation of the statistics behind this read
"Oceanography and Seamanship" by William G. Van Dorn.