26 ft waves kill 2 on Mediterranean Cruise ship

reply to post by zachi

The size of the body of water is only important in terms of the fetch. As long as the wind is blowing over a long enough distance to produce reasonably large seas there is the potential for rogue wave development. The depth of the water has an influence in the sense that as seas move from deeper into shallower water rogue waves can be induced but other than that it doesn't really matter much.

A question just arose in my head: Have there ever been reports of Rogue Waves reaching shore. I googled and found this fairly recent account.

Spectators hurt by rogue waves at surfing contest

By PAUL ELIAS • Associated Press • February 13, 2010

Two huge waves swept away spectators watching a Northern California surfing contest Saturday morning, causing broken bones and other injuries to people standing on a seawall.

"It just came out of nowhere and wiped us all out," said Pamela Massette

"This is probably the tallest waves I've seen. They're not the thickest, but they are the tallest," Bart Miller of Half Moon Bay said after coming out of the surf.

Everyone's concentration was on the contest when a 5-foot to 6-foot (1.5-meter to 1.8-meter) wave "wiped out the entire seawall,"

I think it stands to reason that these waves would eventually break on the shore at some point. Perhaps they only obtain their max height and momentum when they're off shore.

Is it safe to assume that as they approach land they lose their umph? I am speaking more towards the big ones. The article, from what I could tell didn't mention the size of the initial waves, only the secondary 5 & 6 ft ones. Powerful in of themselves but by no means 26 ft.

reply to post by UberL33t

That California situation seems to be more a case of a combination of rising tide and large surf, not really true rogue waves. People were where they should not have been given the conditions.

It is thought that rogue waves are a transient phenomenon, that they spring up and disappear in short order. This being the case it's unlikely that one could make it to shore.

Originally posted by watcher73
You seem to have no sense of context with the single rogue wave thing.

I can't speak for this poster, but I'm pretty sure he has a fair idea of the "context with the single rogue wave thing. " Although judging by this post...

It's almost funny to see you in here answering the OPs questions. It wasnt long ago that science said things like rogue waves and white squalls (great movie) didnt exist.

... you may be harbouring some personal feelings towards this poster which is influencing your responses.

Originally posted by watcher73
It's cool though if you want to forget you put "wavelength (steeper)" and concentrate on me not getting some supposed context that is mostly irrelevant to your mistake.

I understood the context of the post quite clearly, but I guess some could be forgiven for not getting it.

Originally posted by watcher73
If you really want context, you just explained to all the retards that short wavelengths are always steep and long wavelengths are always not. Neither of those are true, but its what you said 'in context' with the rest of what you said.

I can see how some "retards" may have taken it this way. Well I have a certain familiarity with waves that only a surfer can have. Although I've only been surfing solidly for a couple years, I've always had an affinity towards waves in general. So for the afforementioned "retards", I can tell from my experiences (and a little common sense ) that if you have a given wave height (amplitude), a shorter wave length or period (the time it takes for consecutive crests to pass a given point), will have steeper faces.

For example, a 6ft long period (16 second +) swell is going to have a significantly different wave profile compared to a 6ft short period (9 second or less) wind swell. And in heavy winds, it can also cause large peaks out to sea to topple over (break) when the wave face gets too steep. This is obviously much more hazardous than mellow, rolling swells.

So as Phage previously mentioned, waves whipped up by a close proximity storm will generally have steeper wave faces than an equivalent wave size long period swell which has originated from a considerable distance.

[edit on 4-3-2010 by Curious and Concerned]