Rogue Wave

[johnar]

how common are Rogue Wave? and In my mind you have no warning time at all, so it makes me think what kind of damage would you be looking at? Demast? sink?

If you did have some warning time I would guess you head into it?


Dutch

[DaveC]

Rogue waves are common, the size depends mostly, but not always, on current conditions... IE a calm day rogue wave may be small, a storm rogue wave might be huge.

Survival and damage.... well, too many variables.... size, breaking or not, angle, speed, your boat specs and condition, you, warning time.....

I suspect survivability usually boils down to how loudly you scream "H*LY SH*T!!!". The louder you scream, the less chance of survival.

Why not?

[GordMay]

"It's scary to have a 30 foot wave chasing you. If you are steering, you don't look back. The crew looks back for you, and you watch their faces. When they look straight up, then get ready!" ~ Magnus Olsson

Who was it who said: "Waves are not measured in feet or inches, they are measured in increments of fear."?

[hummingway]

Rogue wave - Wikipedia, the free encyclopedia
"Monster" Waves Suprisingly Common, Satellites Show

I remember watching something quite a few years back where they talked about certain areas seemed to generate more reports of rogue waves. They touch on it in the national geographic article. They used to think mariners used them as an excuse for their mistakes but if I recall correctly some russians sailors had captured some photograph of their vessel being damaged in an area where a lot of reports were coming out of and now sattelite imagery has confirmed they happen a lot. At least they dont seem to stick around long.

[GordMay]

Originally Posted by hummingway

...
I remember watching something quite a few years back where they talked about certain areas seemed to generate more reports of rogue waves...

Extreme (rogue) waves often occur in areas were waves propagate into a strong opposing current. A well known example, where many large ships have encountered difficulties, is the Agulhas current outside South Africa. The strong current going south, meets strong swell from storms in the Antarctic Ocean.
In areas where waves from storms in the open ocean, approach shallower waters (ie: Norway), the waves will be refracted and diffracted, thus focusing the wave energy.
It's more difficult to explain extreme waves occurring in the open ocean, far from variable bathymetry or ocean currents.

[Randyonr3]

From experance.. we know full well what they are.. a couple years ago we left San Francisco headed north.. Just about the lighthouse at Pt. Reyes, had one break over the beam... My dodger and bimini are made of 1&1/4 stainless and they were both ripped from the boat.. The auto helm was on and we were tucked up under the dodger when it hit so it took us by surprise.. we figured it was somewhere around 15 to 18 feet.
The cockpit filled with water and the companion way turned into a waterfall..
We both sat there in shock looking at each other, and when looking down into the boat, there was about 6 to 8 inches of water above the floor..
Took us a couple hours making circles to pick up all our gear that had been washed over including our dink...
Hasnt changed anything, as we've traveled a few thousand miles and thats the first and only time it happened.. Just one of those things

[scook1]

What a scary story. Anybody else have personal experiences with a large rogue wave?
Spencer

[barnakiel]

Yes, I have such a story:

I was crossing the Resko lake when a rogue wave came unexpectedly from nowhere and pooped the cockpit. You will understand my disillusion with sailing at that time if I tell you that I was sailing an Opti.

But I have not met any rogue waves from that time on. Sure they exist but must be either very rare or common only in high latitudes.

b.

[r.furborough]

There was a documentary on Discovery or some similar channel not so long ago. Rogue waves are more common than I would want, in fact on the East Coast of Africa there is a current that under certain weather conditions is notorious for rogue waves, so bad that commercial vessels are now permenantly navigating around the area to avoid them.

[s/v Jedi]

I remember the securite VHF calls on the North Sea, warning pleasure craft for the wake of one of the fast ferries... I think it was the Seacat. When the tide runs out or in (don't remember) her wake interacts with it in a way that has capsized some boats. I always found it a non-event but I guess when the conditions are right, it can turn into a rogue wave.

I think I heard more stories about the wake of ships but don't remember the details... anyone?

cheers,
Nick.

[boatman61]

Yeah I believe three guys were killed near the Isle of Wight when the Ferry to Cherbourg's wake capsized their boat one night... big investigation into mysterious sinking and the Inquiry came up with that... seems the times etc all tied in..
But I could be remembering a bit wrong.... David... over to you....

[John A]

I seem to remember someone claiming that rogue waves were the result of two different wave sets traveling in slightly different directions meeting to creat a wave height that was the sum of the two and was of short duration. I know this sounds rather ambiguious and needs futher investigation, but it sounds plausable..

I've encountered a 15 foot swell of 9 second duration from, say, ENE with a wind wave of 5 feet and a different duration from the NE and when the wind wave happens to cross the top of the swell with your boat sitting there, it appears to be a rogue wave.

Once while sailing north past St. Lucia I seen a white wall of water about a half a mile in front of me and it was about a mile wide. I had to check my shart to be sure it wasn't a reef line! I took it at a 45 degree angle and about four wave sets were over ten feet in height. They were followed by about two hundred yards of very confused seas. Any ideas?

[Christian Van H]

Originally Posted by barnakiel

I was crossing the Resko lake when a rogue wave came unexpectedly from nowhere and pooped the cockpit. You will understand my disillusion with sailing at that time if I tell you that I was sailing an Opti.

Sounds like a rogue WAKE to me...

[tagline]

John A - I am going to guess that the four waves [ wave train or tsunami ] you saw where produced by an earthquake. If you hear the reports from locals who witnessed the coastal devistation from the recent Chile earthquake they all report
3 -4 waves in a row approaching the shore. Rogue waves are usually singular waves which occur in the open ocean. They have wave height's which are twice the normal height of the surrounding sea.

[GordMay]

Significant Wave Height (WVHT) is measured Trough to Crest, and is approximately equal to the average of the highest one-third of the waves during a 20 minute sampling period.

whereas

Tsunami Wave Amplitude (AMPL) is measured relative to Normal Sea Level - it is NOT Trough to Crest .