"Roger Long" wrote in message
...

Half the wave is down and half the wave is up Roger Long
This seems to be a good time to raise this issue. The Annapolis Book of
Seamanship, and others, agree with your statement, Roger.

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 ?