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Old 12-09-2009, 19:07   #46
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"Olden days" refers to the really "olden boats" like the Triton. The plexiglass side window and hatches, ports is probably lost a lots of original strength due to age. New boats have better materials and mounting systems that can usually withstand heavy seas impacts better than 30+ year old plexiglass.
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Old 12-09-2009, 19:36   #47
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Originally Posted by osirissail View Post
"Olden days" refers to the really "olden boats" like the Triton. The plexiglass side window and hatches, ports is probably lost a lots of original strength due to age. New boats have better materials and mounting systems that can usually withstand heavy seas impacts better than 30+ year old plexiglass.
New plexi can fail too. It's still a fairly common incident in heavy weather. When we replaced our (rather small) ports we went with 1/4" tempered and have provisions for storm covers- belt 'n suspenders.

Old brittle plexi is just a hazard .
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Old 12-09-2009, 21:30   #48
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If you were prepared for it, it was not rogue.
Interestingly, I have read a study, based on satellite photography sources, where they prove that both the size (height) and the 'it came from impreditable direction' legends were put to grave (let's hope). Objectively, the only wave that is out of the range of normal wave physics is the tsunami then.
I do not think this is the case. First, the existence of "Rogue Waves" was just recently established. I believe the first scientific proof was from a north sea platform in 1995:



I think the study you are referring to is the MaxWave project. Their findings are quite different from what you suggest: http://www.soest.hawaii.edu/PubServices/2005pdfs/Rosenthal.pdf

Finally, the Deadliest Catch actually caught a wave on video that was both larger than the ambient wave train significant height and came from a different direction:
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Old 12-09-2009, 21:49   #49
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Almost looks like he is quartering, almost abeam to the waves there. Dangerous? Hard to tell but it looks like the wind is blowing from starboard.
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Old 12-09-2009, 23:28   #50
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I believe the first scientific proof was from a north sea platform in 1995:

a wave on video that was both larger than the ambient wave train significant height and came from a different direction
There has been quite a lot solid observation of large waves for much longer than that. Just for example: "1933 in the North Pacific, the US Navy transport USS Ramapo triangulated a rogue wave at thirty-four meters in height. 1942, the RMS Queen Mary was hit by a twenty-three meter wave (it stove in ports at that height)."

But those sort of experiences did not produce the sort of statistical data scientists need to develop new waves models. That started happening first when the 'hurricane hunter' planes were fitted with radar which could measure wave height. In the 1980's there was a hurricane hunter that measured wave heights in an Atlantic storm and the data suggested there were 10x more large waves (greater than 2x sig height) than predicted by the then current linear model (Ralyeigh distribution). Since then there has been a whole host of statistical measurements from oil rigs and satellites showing basically the same thing - 10x more waves than predicted by the standard linear model. So the science has moved on to using non-linear models that have a higher tail frequency.

As to rogue wave direction, the science I have seen suggests most, but not all, follow the same general direction as the underlying wave train. That is the direction of wave energy flow. I believe this is the case in that fishing video. It looks to me like the captain is quartering the waves (he is definitely not powering directly into them) and the big wave came from the same stb quarter. This is certaintly our own experience, and what you see in the very good video of the sydney to hobart storm (probably the best recently filmed large waves).
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Old 11-02-2020, 07:59   #51
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Re: Rogue Wave

The Grand Unified Theory of Rogue Waves
Rogue waves — enigmatic giants of the sea — were thought to be caused by two different mechanisms. But a new idea that borrows from the hinterlands of probability theory (Large Deviation Theory - LDT) has the potential to predict them all.
Sailors, facing an imminent storm, don’t have years to study the growing waves around them, but the new framework represents small steps toward the long-term goal for rogue wave prediction — machinery that scans the ocean and sounds the alarm when it’s time to batten down the hatches. LDT tools, once they’re modified for the open ocean, could be one way, for those on boats like the München, to know the moment a rogue wave starts focusing.
https://www.quantamagazine.org/the-g...=pocket-newtab

“Experimental Evidence of Hydrodynamic Instantons: The Universal Route to Rogue Waves” ~ by Giovanni Dematteis et al.
https://journals.aps.org/prx/abstrac...sRevX.9.041057
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Old 05-01-2021, 06:23   #52
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Re: Rogue Wave

Physicist works toward forecasting rogue waves along Vancouver Island's west coast
Johannes Gemmrich, a University of Victoria physicist, has partnered with two graduate students to develop a real-time public monitoring and forecasting system for rogue waves, which are usually more than twice the size of their surrounding waves, and typically surface every couple of days.
The monitoring systems are collecting data on how frequently the waves occur and how big they are, with the goal of having a warning system in place some time next year.
Information will also be made available by the CoastSmart Initiative, a pilot project between the federal government and the districts of Tofino and Ucluelet, later in the year.

Morehttps://www.cbc.ca/news/canada/briti...land-1.5861347

Coast Smart https://coastsmart.ca/
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Old 02-04-2022, 15:58   #53
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Re: Rogue Wave

New Record Rogue Wave

Researchers have announced [1] that a 17.6 meter [58 Ft] rogue wave – the most extreme rogue wave ever recorded – has been measured in the waters at Amphitrite Bank, approximately seven kilometres from the Ucluelet, B.C., shoreline, in water 45 metres deep.
The rogue wave was recorded on November 17, 2020, by Victoria, B.C.-based, MarineLabs Data Systems (MarineLabs). It is the subject of a scientific report [2] by Dr. Johannes Gemmrich and Leah Cicon, both of the University of Victoria, published last week in the journal, Scientific Reports.
Rogue waves are defined as one-off waves, that reach at least twice as high as the surrounding ocean swell.

[1] “Record-Breaking Rogue Wave Recorded off the Coast of Vancouver Island” ~ News provided by MarineLabs
https://www.newswire.ca/news-release...830202783.html

[2] “Generation mechanism and prediction of an observed extreme rogue wave” ~ by Johannes Gemmrich & Leah Cicon
https://www.nature.com/articles/s41598-022-05671-4

More about ➥ https://www.theweathernetwork.com/ca...as-a-jumbo-jet
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Old 04-06-2022, 05:05   #54
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Re: Rogue Wave

“THE GARGANTUAN ROGUE WAVE” ~ National Geographic
Mathematicians are working on predicting these sudden, towering waves. How? By combining real-world data, collected from monitoring buoys, with statistical models.
https://www.nationalgeographic.com/s...ravel_20220603


“Rogue wave ahead” ~ MIT News [2016]
New prediction tool gives 2-3 minute warning of incoming rogue waves.
https://news.mit.edu/2016/prediction...gue-waves-0225
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Old 04-06-2022, 06:40   #55
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Re: Rogue Wave

“New prediction tool gives 2-3 minute warning of incoming rogue waves”

Oh that fine then , I can be 900 feet away in that time !
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Old 04-06-2022, 06:58   #56
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Re: Rogue Wave

There is a whole lot of complexity to rogue waves.

at level one you have a statistical distribution, which as mentioned has recently been changed to have a bigger tail

at level two you have relatively obvious local conditions - often ocean currents with/against the wind and sea mounts/shelving of the bottom and the interaction of multiple wave trains (from multiple low-pressure systems). These affect the distribution

at level three there are various 'one off' sorts of events: from 'big events like landslides down the slope of a sea mount and undersea earthquakes, to smaller events like ship wakes.

note: in levels 2 and 3 most rogues will be 'on-axis' (eg roughly aligned with main wave train) but there is the possibility of off-axis rogues depending on the specifics of the special conditions/event.

And at level four there are quantum mechanics effects, which are not all that well understood, but in some small set of circumstances allow one wave to 'steal' energy from all the waves around it and grow to a rogue (has been observed in light waves patterns also). Note: my understanding is that these are always 'on-axis' rogues.

For the first three levels, a good seaman will have a feel and build experience of, and can be 'prepared' at some level - that is he knows when the risk probability of tail events is increasing and in those circumstances takes precautions (like a drogue) earlier than he might in other 'normal' circumstances.
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Old 04-06-2022, 08:08   #57
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Re: Rogue Wave

The general understanding of “rogue” wave is divided into two components: a “giant wave” that arises in storm seas from the same direction as the on-coming seas generally, and an unusually large wave that suddenly arrives from a direction not that of the on-coming seas and not necessarily during a storm or when otherwise in high seas,

We’re commingling answers. The picture in the original post is one of a “giant” wave apparently arriving from the direction of the storm seas generally. If sailing, that wave might be approaching you on, say, the starboard bow. If the boat is not already rigged for heavy weather sailing then you’re not going to have time for anything other than attempting to bring the boat up some to meet it and “pray” that you have enough weigh on to get over it, etc. You are not going to heave-to, or put out a sea anchor, or attempt to lie the boat a-hull in the maybe 12 to 17 sec you might have before the wave reaches you. So, half of our answers refer to having the boat rigged for heavy weather sailing, or not sailing in heavy weather as in lying to a sea anchor, or being hove-to. Kretschmer favors having the vessel fore-reaching in storm conditions in his Kaufman 47. So, one must decide early how to prepare to handle “giant (storm) waves” when sailing in storm seas.

The true “rogue wave” is as described in the case of a large wave arriving (or arising) suddenly, without warning, to hit the vessel amidships. It might be a “giant” or “gigantic” wave as well. But whatever size it is it will likely be a surprise occurrence. If you are lucky enough to to see it coming the best thing IMO would be to turn and “power into it” probably by flipping on the diesel. Hope (pray) there are no lines overboard to foul the prop. If it is steep and catches you by the beam the boat might roll over. But once again, I doubt there will be time to reset the sail trim or sail plan in the few seconds to maybe a minute that you might have.

So, the best advice I can muster is to practice good seamanship at all times. Stay tethered, keep at least one hatchboard locked in place, have stuff properly stowed on deck, etc. Being ready and able to take an action at the time as the situation arises. There a lot of rogue waves out there. Most are not “gigantic”, so create no sensationalism. But one might still eject a crew from the cockpit if not tethered if the boat is rolled hard (but not over).
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Old 04-06-2022, 09:15   #58
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Re: Rogue Wave

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And at level four there are quantum mechanics effects, which are not all that well understood, but in some small set of circumstances allow one wave to 'steal' energy from all the waves around it and grow to a rogue (has been observed in light waves patterns also). Note: my understanding is that these are always 'on-axis' rogues.
This occurs when multiple independent wave sets are traveling in the same direction but at different speeds and with different amplitudes. At various positions along the path a subset of the waves will coincide in place and time. Their amplitudes are additive, so the “combined wave” (amalgamation) may grow to a gigantic height, depending. (We sometimes see this effect mentioned in NOAA forecasts as combined wave height.) It will persist as long as that subset of waves is more or less traveling together. Once they start to separate based on different speeds, the combined wave amplitude dissipates. This is happening all of the time when waves are propagating. Individually, none of those waves would be rogue b/c they are all traveling in the same direction. On-axis, as stated above. So they would not become “a rogue” simply as a matter of being together at one place and time, etc.
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Old 04-06-2022, 09:52   #59
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Re: Rogue Wave

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This occurs when multiple independent wave sets are traveling in the same direction but at different speeds and with different amplitudes. At various positions along the path a subset of the waves will coincide in place and time. Their amplitudes are additive, so the “combined wave” (amalgamation) may grow to a gigantic height, depending. (We sometimes see this effect mentioned in NOAA forecasts as combined wave height.) It will persist as long as that subset of waves is more or less traveling together. Once they start to separate based on different speeds, the combined wave amplitude dissipates. This is happening all of the time when waves are propagating. Individually, none of those waves would be rogue b/c they are all traveling in the same direction. On-axis, as stated above. So they would not become “a rogue” simply as a matter of being together at one place and time, etc.
Now, it might also be that wave sets traveling along different directions meet and combine amplitudes for a short time as described above, producing a giant wave. However, this “giant” might be slightly “off-axis” so would appear more rogue-like. Hence, “a gigantic rogue wave.” These might persist longer b/c one crossing wave set would not quickly out run the other. The two sets of wave amplitudes might remain together across potentially a wide wide area of intersection.
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Old 04-06-2022, 09:58   #60
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Re: Rogue Wave

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I agree with you, but what brought it up was that the History channel was airing the science behind them and all the ships that have encountered them, they just never mentioned how to deal with them

thanks for the help.

Jeff

Honestly high hi up on the list of actual dangers is this?

You should ignore hype & drama intended to sell commercials. According to the History Channel, sharks are all conspiring against us and aliens founded Earth too

Humans have a natural tendency to downplay the dangers they CAN address, while exaggerating the dangers they cannot. Smokers worrying about long term economic trends etc

Statistically you're in far greater danger from much more mundane things -- years of US Coast Guard stats show booze and inattention are the cause of almost all serious accidents.

Instead of worrying about rogue waves, I'd worry about whether my cutlass bearing needs replacing.

But should you encounter a rogue wave -- and that means little or no warning -- you'll possibly get a knockdown, then the boat will self-right. The only thing to do is make sure everything stays in place including fuel tanks, bilge hatches, ovens, anchors etc You may be dismasted in which case that's a whole thing to be prepared for (the GGR requires some system of jury-rigging a mast)
If you're far offshore it may stay a huge swell that doesn't break
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