Wave height

[tangomoon]

As the fashion has been for wave height to be estimated from the bottom of the swell/wave to the top, does anybody know whether that is now the official line or is the mean method still in force in more strictured and accurate circles.

 

[sarabande]

Wiki thinks that height is measured from trough to crest.

The Scripps Institute discusses the measurement of "significant" wave heights" and refers to use of Doppler measurement "of the troughs of the waves compared with the crests".

The Manly Hydraulics Lab in Australia uses
"Wave Height - The vertical distance between a wave drest sic and the next trough. "

They have an excellent page of definitions for wave geeks, including ways to estimate the power of a breaking wave.
http://www.mhl.nsw.gov.au/www/wave_glossary.htmlx#WHEIGHT

 

[tangomoon]

TY for that

Yes Wiki does say that but it's only info added by who ever I believe

Not long ago wave height was stated as being from sea-level, which of course would be the middle of the wave and half the height of bottom to top of swell or wave.

Some good time ago, a person was telling me that waves were approx 4 metres on a certain headland. I asked if they really did mean 8 metres. The discussion revealed a new way (top to bottom) was being used by the new wave yachtie

 

[Auntie Helen]

Hmmm, as a complete ignoramus I always assumed wave height was from bottom to top, i.e. maximum distance you'd get bounced about (thus the 4metre wave would be 4 metres from top to bottom). It's the more logical/automatic measure than from sea level when you're hanging on for dear life dropping down one of them.

I remember reading somewhere that people usually overestimate wave heights as they measure them on a diagonal (from trough to crest over a couple of metres wide, or however wide the wave is) rather than perpendicular height. Doesn't sound as cool to say 'we were out in 2 metre waves' than '3 metre waves' though!

 

[eastcoastbernie]

I prefer this method of measurement:

smooth as a millpond
short chop
quite big waves
big waves
bl**dy great enormous waves
Ok I've had enough, I want to go home waves.

/forums/images/graemlins/laugh.gif

 

[tangomoon]

Reef early!