Rogue Waves

...a recent excerpt from Professional Boatbuilder magazine

Rouge Waves

The origin and frequency of rough waves have long been mysteries. While some dismiss 82’(25m) and higher waves as rare freaks, those who have spent time in mid-ocean suspect otherwise. For disbelievers, Adlard Coles in his classic text Heavy Weather Sailing assembled numerous startling photos of large breaking waves that can consume small boats and do damage even to large ships. Beginning in 2000, a European Union project called MaxWave conducted a three-year-research effort to explain how rogue waves occur, how frequently they appear, and whether their formation might even be predicted. The results would be of interest to naval architects and marine engineers, not only for ship design, but also for other structures such as offshore oil-rig platforms.

Early in the project the European Space Agency donated a chunk of time and resources by offering synthetic aperture radar scanning of the Earth’s oceans from its ERS-1 and ERS-2 orbiting satellites. Each took 6.2 x 3.1-mile (10 x 5-km) “imagettes” of the sea surface, recorded every 124 miles (200 km). During the three-week operation about 30,000 separate imagettes were captured and later analyzed. What scientists found were more than 10 individual giant waves that measured more than 82’. “The waves exist in higher numbers than anyone expected,” said Wolfgang Rosenthal, senior scientist with the GKSS Research Centre in Geesthacht, Germany. As if to punctuate the findings, during the same period as the ocean scans, two cruise ships were struck by monster waves: the Bremen and Caledonian Star had their bridge windows blown out by 100’ (30m) waves. The agency says that during the past two decades more than 200 supertankers have been lost to severe weather, theorizing that many of these losses may have been caused by large breaking waves.

An extension of MaxWave is a separate project called WaveAtlas, which is making use of the imagettes to catalog rogue events. The principal investigator is Susanne Lehner, associate professor in the Division of Applied Marine Physics at the University of Miami (Florida). Lehner, who worked with Rosenthal on the MaxWave project, says, “Looking through the imagettes almost feels like flying, because you can follow the sea state along the track of the satellite. Other features such as ice floes, oil slicks, and ships are also visible on them, and so there’s interest in using them for additional fields of study. Only radar satellites can provide the truly global data sampling needed for statistical analysis of the oceans, because they can see through clouds and darkness—unlike their optical counterparts. In stormy weather, radar images are thus the only relevant information available.”

While rogue waves were sighted in some of the expected places, such as in the notorious Agulhas Current off the east coast of southern Africa, they were also found apparently randomly around the globe, though usually near weather fronts and low-pressure systems.

It’s easy to view this work as the logical and longawaited technological extension of Lt. Matthew Maury’s landmark work of the 19th century, in which he divided the ocean into quadrants and collected data from ships’ captains to develop the world’s first pilot charts. His work enabled the great sailing clipper ships to achieve shorter, faster passages around the five major continental capes. Perhaps the WaveAtlas will make voyages safer and more economical for boats and ships of the 21st century.

 

I found the photos interesting. It does not change the fact that boat and crew of average abilities must be able to handle anything, if you go out to play. Rule #1 seems to be, never go out in a boat that has more than 1 hull, unless you can live upside down. The wind is supposed to lift and flip it upside down. That is how it is designed. It is not designed to flip back to the upright. Due to the " suction effect " of the hull connecting deck and the mast " stuck " in solid water. -------- Rule #2, a mono is and should self right. Failure not to self right is premeditated and inexcuseable. I now give the soapbox up to the next speaker. Signed, "Mr. Cautious ".

 

I am replying to the dangers of a " Rouge Wave ". Boats sinking at both southern capes are often mentioning large ships swamped or damaged by Rogues. Nothing new in the past. Just very well recorded in the present and future thanks to electronic media and insurance records. In my over simplistic armchair design solution I see only 2 solutions. --------- 1 is to travel in the safety of a submarine of any size and deep enough not to be in danger from Sunami or Rogue. ---------- 2 is not to go on the sea since they, Sunami or Rogue, are as predictable as tornados were 60 years ago. It seems as fast as we cure one danger, we get 2 more to work on. Mother Nature has no respect for boaters.The "chicken" is off the soap box. -----I have gone thru a North Atlantic storm in a destroyer. A few waves went up to the 05 level. I would not know . I was strapped in my bunk, when a few waves actually put me up against the overhead. To this day I still have a bone bump on my forehead from the impacts.

 

last week, in mediterranean sea, a cruising ship "Voyager" has been damaged from a a rogue wave; the wave shattered multiple pilot deck hatches creating a shortcircuit in steering and engine circuit (that's the official press report); as results of the accident 3 engines flamed out, the ship with only one engine operative was unable to manoveur for 4-6 hours; images and clips from rescue helicopter showed heeling angle of about 35° with heavy rolling and pitching; a dozen of tourists aboard have suffered slight injures; after 4-6 hours of engine troubles the ship's crew was able to fix one or two engines and reached Cagliari's harbour (Sardinia), where she is currently moored to repair her damages. Tourists got back home on plane.
Meteo conditions: localized low pression area, force 8 to 9, gusts 'til 60-65 knots, estabilished wind >40 knots for at least 24-30 hours in the area, 200 NM of fetch to increase wave size, some meteorologist talked of wave models wich predicted normal waves 10-12m (33-40 feet) high; the rogue wave wich reached command deck can be scaled up to 18m, at least.
Have you got any further informations about this accident??

best regards
Mistral

 

Do you know where any of these images were printed...papers,etc. That you might post post some?

 

Re: images and clpis

i've seen a clip on TV, taken from the rescue helicopter, i'll try to catch some image from the newspapers and post them here in the next days

Mistral

 

I've been hit by two rogue waves. One of the NE coast of Brazil while delivering a sailboat to Martinique. We were sailing the trades with maybe 8-10 foot seas when out of nowhere a 30 foot wave made us broach.
The second time was aboard a trawler in the North Atlantic. A Northester had been blowing for about ten days and the seas where about 20-25 footers. I heard what sounded like a freight train, it was a huge breaker. It completely submerged the 85' boat up to the bridge. I was at the stern by the gallows and somehow managed to hold on to a cleat.

 

Norwegian Dawn

I'm sure by now that most of you have heard about the ocean liner the Norwegian Dawn being hit by a rogue wave approximatly 70 ft high.
This wave broke windows on decks nine and ten, with deck ten possibly being eight levels above the water line.

http://www.yachtforums.com/forums/showthread.php?t=2970

 

o man.... waves so big can sink a tanker, so what gonna hapend if small (12 meter) yacht will meet waves like that?

 

A boat with a length much shorter than the wave period will mainly go up and down.

 

Rogue Waves?

If these waves are more common than it has been previously thought, then perhaps "Rogue" isn't the right name for them.

Something closer to "Frequent big bas&*%d" is more appropriate.

 

We can't change the waves. How about the boats? 200 tankers lost? Cheaper to replace the boat and crew, per our CEO. We are moving cargo, not saving boats or lives.

 

Let's try making SAFER boats, easier to get out of, harder to capsize...multi-hulls, anybody? Oh, and more liferafts. How about a 1-person liferaft for each crewmember, just like for Naval pilots.

 

Latest findings on giant waves

http://edition.cnn.com/2005/TECH/science/08/04/giant.wave.ap/index.html


Yoav

 

BBC news report

I thought I might post this in a print form as often the web references disappear after a short time



....courtesy of BBC news...

Hurricane caused 'tallest wave'
Hurricane Ivan generated a wave more than 90 feet (27 metres) high - thought to be the tallest and most intense ever measured - scientists have revealed.

It would have dwarfed a 10-storey building and had the power to snap a ship in half - but never reached land.

The wave was recorded by sensors on the ocean floor as Hurricane Ivan passed over the Gulf of Mexico last September.

The observations suggest prior estimates for extreme waves are too low, researchers warn in Science.

Hurricane Ivan caused more than 100 deaths and left a trail of devastation as it swept over several Caribbean islands and part of the United States.

As it moved over the Gulf of Mexico, it triggered sensors deployed by the Naval Research Laboratory to measure water pressure.

Scientists at the Washington-based laboratory in the US used the data to calculate the extreme waves created under the eye of the storm.

The distance between the crest of the biggest wave and its trough was 91 ft (27.7 metres) but they suspect the instruments missed some waves that were as tall as 132 ft (40 metres).

The waves were bigger than expected, suggesting theoretical models of waves whipped up by hurricanes may have to be revised.

"Our results suggest that waves in excess of 90 ft are not rogue waves but actually are fairly common during hurricanes," lead author Dr David Wang, told the BBC News website.

He said that since hurricane activity is predicted to increase over the next few decades, more research like this needs to be carried out.

The 91 ft wave was the largest individual wave measured with instruments in US waters, he added.

It echoes the wave depicted in the film, The Perfect Storm, which was 100 ft tall. The story is based on the 1991 storm off Gloucester, Massachusetts, which was one of the strongest in recorded history.