Estimating Wave Size?
 

I see people quoting the size of waves that they were running in. How does one go about estimating the size of the wave? It seems very arbitrary, are there good rules of thumbs to go by?

In oceanography, wave height (fig. l-31) is the vertical distance, usually measured in feet, from the crest of a wave (the highest portion of a wave) to the trough of the wave (the lowest portion of the wave). This differs from the "wave height" or "amplitude" normally used in physics, in which the distance is measured from the "at rest" or midline position to the crests and troughs.

http://www.tpub.com/content/aerograp...s/14269_58.htm

It seems to me that the average boater over estimates actual wave height most of the time. I work off shore, and and most of the "marine crew" I work with (ie captains and first officers) usually call wave height pretty damn good.

You hear guys saying they run x mph in 4-6's or 6-8's...... OK sure.... True 6-8's are no joke.

I'm guilty of the wave over estimation as well, don't get me wrong... :)

I always listen to the marine forecast and check a few bouys on the NOAA website before I go out. So I figure if NOAA says it 2-4 ft ...its 2-4 ft.

Major culprit...

http://i79.photobucket.com/albums/j1...ck-daniels.jpg

I thought if their keychain said APACHE or CIGARETTE that was the major culprit! :D

Big mouth x ego + % boat brand = wave hieght if alcohole is included in said formula add 2 feet:drink:

To some a swell is a wave.
But to me, they are not the same.
And yes, you can run 60-80mph in 8ft swells.
But 8ft waves would be punishing, depending on the frequency.

simple .stop the boat, stand up,,when your in the troughand look out ..if it looks eyelevel, its 4~5' if it looks as high as your head or just over its 5~6' if it looks twice as high as you 8~9' if you just sh*t yourself and said were screwed then hollered mayday on the radio, your rolling in 10 footers..if you look up and see a 2 story house, have resolved yourself to the fact your going to die, locked yourself in the cabin with an appeltons and coke and a cuban cigar, waiting for Davey Jones to knock on the door and joing the party, its prolly over 12

I'm sure if all you have is the keychain it can't help.

What do those run now $7 or $8 bucks? :drink:

I've been in a 10 foot plus chop. I do not want to be there again. It was fun and scary at the same time. The boat took a hell of a beating and so did I. Best speed i could make was 2-5 Knots. When I finally got into the inlet I was headed to I couldn't beleive how exhausted I was or how bad shape the boat was in.

I go by the NOAA bouy data for the area that I boat in on the day I'm boating. The bouy data usually shows dominant waive period and height (which as I recall is the average of the highest waves/swells not the highest).

I don't even bother to try to eyeball it beyond "reflecting pool/flat/bumpy/really bump/going to lunch someplace in the harbor".

...and you see one of the other OSO members buzzin by at normal crusing speed. LOL

NOAA takes an average of the top 1/3 highest waves... the biggest wave around is usually 2 times this average.
so if NOAA says that there are 2-4' waves out every once in a while you are going to run accross an eight. which may be the reasoning fo the over estimation.

Ernie