Wave Hights

[hlb]

Where are waves measured from. Is it from the trough to the tip, or from sea level to the top or some other way.

<hr width=100% size=1> Flags Solly MFBR</font color=red>
Haydn

 

[Gludy]

From the bottom of the trough to the crest of the wave

<hr width=100% size=1>Paul

 

[Bejasus]

The amplitude is the height of a wave, measured vertically from the centre line to a crest or a trough.

See <A target="_blank" HREF=http://www.users.zetnet.co.uk/computing/MainPage/SecDepts/Physics/Resources/Glossary/Wave.html>here</A>



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[tcm]

yep, that's correct. hence lots of peeps set off with forecast of 1-2m waves and ooer, the height from top to bottom is up to 4m...

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[boatless]

Trough to crest does help in the bar afterwards though.

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[Metabarca]

can anyone officially confirm that the centreline to trough/peak approach is the one adopted by the Met office et alii?

<hr width=100% size=1>Adriatic links here: <A target="_blank" HREF=http://www.comoy.com/saillinks.html>http://www.comoy.com/saillinks.html</A>

 

[Ships_Cat]

Errr, cough, cough what can I say.

That definition is so in physics but as far waves in the sea are concerned Wave Height is the vertical distance from the trough to the crest.

Suddenly thought that I may have been wrong all these years /forums/images/icons/blush.gif so rushed off to double check. But no, Bowditch says the same, is from trough to crest /forums/images/icons/smile.gif.

Immeasurably relieved cat

John

<hr width=100% size=1>I am the cat but I am only 6.

 

[jimi]

How big is this one?

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[duncan]

Re: How big is this one?

does it matter? you won't get back to the bar to discuss it anyway! /forums/images/icons/smile.gif

<hr width=100% size=1>madesco madidum ..../forums/images/icons/smile.gif

 

[hlb]

Thought it was me being a bit thick. But looks like no one else can agree either. Suspect Mr HOO is right as all waves I see seem twice as big as forcast. On the other hand my new 2.6 dinghy says certified OK in 2metre waves. So I guess that means 4metres! Who needs a life raft!!..../forums/images/icons/smile.gif

<hr width=100% size=1> Flags Solly MFBR</font color=red>
Haydn

 

[BarryH]

I don't need a little diagram telling me how to measure waves. I leave that to the feeling in my pants ta!

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[BustinAround]

Re: How big is this one?

about photoshop 6, give or take...

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[jimi]

Re: How big is this one?

its actually a genuine wave.

see <A target="_blank" HREF=http://billabongxxl.com/04/main3.asp>http://billabongxxl.com/04/main3.asp</A>

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[Bejasus]

part of todays weather forecast I receive on board here twice daily. Note the zero baseline which should be mean sea level there for wave height is forecast above this.

and besides our Captains said 'make it so', so there.


Yes we are having some nice weather here off Denmark this week.
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[DavidJ]

National Geographic definition + game

Game first try
http://www.nationalgeographic.com/volvooceanrace/interactives/waves/index.html
The National Geographic definition is crest to trough

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[hlb]

Re: National Geographic definition + game

So no wonder I'm confused, no one else can agree either!! Can I just have a straight answer please......How high are the bloody waves!!!

<hr width=100% size=1> Flags Solly MFBR</font color=red>
Haydn

 

[jimi]

Re: National Geographic definition + game

Acshully ... the height is almost irrelevant as its the shape that's important.

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[KevB]

The "old" way to measure waves was at "face" value, from the trough to the crest. This is the way oceanographers still measure waves. Then things changed and wave height was measured by it's mean height but this confused a lot of people and was the cause of lots of law suites where forecasts for 3' - 6' waves actually meant waves of up to 12 foot crashing onto the beach. Surfers didn't like the new way. So now the "old" way is the new "new" way. Not sure who uses what but I don't think there is a standard...../forums/images/icons/crazy.gif


<hr width=100% size=1><A target="_blank" HREF=http://static.photobox.co.uk/public/images/45/99/10714599.s.jpg?ch=97&rr=16:00:39>Nirvana</A>

 

[Bejasus]

Re: National Geographic definition + game

well, I guess if Haydn means how far is he going to fall off the top of a wave to the bottom, then that is crest to trough, but if he is talking about wave height as given in a weather forecast, then the significant wave height given, is from mean sea level to the top of the crest.

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[BarryH]

Re: National Geographic definition + game

Thats wave length, please don't get them started!. True though.

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