Rogue Waves - new research support

[Conachair]

Now showing on Eden+1 "Horizon: freak wave"

And on a broadband near you
http://www.youtube.com/watch?v=0YVZn46KgTs

There was also something about similar non linear wave behavior being observed in fibre optics not too long ago.

[BosnBill]

I have a curiosity about rogue waves so I did a little research. I have seen large swells that seem random and infrequent and it's a real problem if you're running in a following sea and you don't see them coming. I can't imagine these walls of water some as high as 28 metres (90 feet). It seems freakish and almost mythical, but they happen. Here's an article by Dee White on the subject. Very interesting stuff:
http://wgills502.blogspot.com/2011/1...r-reality.html

[Niall1975]

I was on a Semi Sub in the North Sea which was heaving 54ft/16.5m. A few years below the accomodation windows on the rig were blown in by a wave and they were 80ft above sea level. Heres a link to the 100fter that hit the Armada platform a few years ago


http://www.youtube.com/watch?v=KcHvdJoQhUE

Niall

[KellysEye]

>Therefore, a forecast of 10-foot seas in open waters means a mariner should expect to encounter a wave spectrum with many waves between 6 and 10 feet along with a small percentage of waves up to 16 feet and possibly even as large as 20 feet.

NOAA's explanation of their wave forecasts. Not exactly rogue waves but we've often had those wave heights. The biggest one is usually around every seven waves.

[franksingleton]

Not sure if I am really taking this debate further.

It has long been known that waves always come with a range of frequencies and that larger than normal waves occur when two or more wave trains come into phase. The “every 7th wave” being a big one has some statistical support. Just occasionally, waves twice the average will occur purely by chance. I do not know how large a wave can be caused by this effect alone.

Such effects are compounded by wind, really it is swell, against current. The Agulhas current effect becomes really dangerous when a deep low gives a long spell of strong winds opposing the current. Ship captains tell me that ships heading into the big swells go over the crest of a wave and down the other side so fast that they simply carry on diving down into the next wave, especially when it is steep and following closely after its predecessor. Momentum takes over. Whether these are the “holes” that have been mentioned, I do not know.

There are, of course, other reasons for freak waves such as a minor earth tremor leading to a Tsunami type effect. A shock wave type effect can occur when a swell goes through a narrow strait. This is one of the possible causes of seiches around the Balearics. Bottom topgraphy is also, clearly, another factor.

It is probably misleading to look for single answers for freak waves and may be equally so when trying to determine a single reason for one particular wave.

[dharl]

[QUOTE=binch;3206357]One of our most scientific instruments were milk bottles half full of liquid jelly. Lowered under a buoy, we could detect something or other from the way the jelly set. (We had oceanographers on board, very earnest young men with beards.)/QUOTE]

Vodka Jelly?

[James Marinero]

No. He got off on a technicality. The cat was both dead and alive.

That's assuming that there were only two possible states that the cat could be in. Open the Box!

[James Marinero]

We went off the top of the wave and it seemed as if we were going vertically down until we hit the bottom with a bang that caused all the false teeth in the ship to collect in the forepeak.
Whatever induced me to go ocean cruising in a yacht after Atlantic convoys.Masochism, I suppose.
It was raspberry jelly, the better to be able to see it.

I'm tempted to ask 'what was the worst bang you had on a boat', but perhaps it's best left unasked.

Raspberry jelly