Rogue Waves Are Not Bad Luck

Reading Time: 8 minutes

As a card-carrying coward with a well-developed fear of storms at sea, I have long taken a deep interest in accounts of heavy weather at sea, and particularly stories of storm damage and abandonment.

While reading these accounts always scares the crap out of me, I still do so on the theory that the more I know about bad stuff that happens to other sailors offshore in heavy weather, the more likely it is that Phyllis and I can equip ourselves with the knowledge and gear to avoid the same fate.

This has been a learning project that has covered some fifty years, starting with reading the first edition of Heavy Weather Sailing, on through Miles and Beryl Smeaton's account of two roll-overs while attempting to round Cape Horn, to the present day, where the internet makes educating (and scaring) myself ever easier.

A Common Theme

One thing that really jumps out at me from all this reading is that the vast majority of these storm disaster accounts have the following in common:

  • The boat was rolled over or pitch-poled.
  • Said roll-over almost always results in abandonment, particularly these days when calling for help is far easier than it once was.
  • Pretty much every crew stated afterward that everything seemed under control, often for many hours or even days of heavy weather, until a "rogue wave" caused disaster.

A Core Problem

It's this last point that I'm going to write about in this chapter, since I think the key to avoiding the same fate lies there. 

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Chris Smith

John-

I very much appreciate your thoughts on this- I find your rational, conservative approach to be calming when considering a storm at sea, and inspires confidence in my future-self’s ability to skipper a boat offshore…someday. It’s articles like these that keep me coming back to AAC, keep up the good work!

Taras

Hi John,
Very nice article thank you for that.
So if you are offshore, and it blows gale force 8 steady for a day or two, you would deploy JSD, sit and relax?
Thank you!

Conor

Hey John,

Interesting article with lots of sage advice. But I wanted to mention there are two types of extreme wave events. First, are the big waves described statistically by the edges of probability distributions and the second is a true rogue/freak wave not described statistically. You are completely correct in describing the statistical expectation of waves that are bigger than a given Hsig. But this statistical approach to describing a given wave state depends on the usually justified assumption that the waves are growing from wind growth only with minimal wave-wave interaction. In the open ocean, with relatively flat bathymetry, and small current gradients, the underlying assumptions of this statistical wave description are well justified. You also correctly describe the chance of encountering one of these statistically expected larger waves.

The second type of extremely large waves, are the more accurately described “rogue/freak waves”. These are waves that occur that are not described by the typical probability distribution that you summarize well (like the 1:1000 waves). These occur in locations with un-even bathymetry (like sandbars or sea-mounts), geometrical wave-focusing in basins, or when current gradients exist.

In these areas, the waves interact less nicely (technically non-linearly). These unusual situations are believed to lead to cases where waves constructively interfere (add together) to create a very large wave, and appear to remain in this newly-constructed shape. This is of course different than the statistically described large waves where wave-trains pass through each other without exchanging energy. These waves are not comprehensively understood, as we have very few ocean measurements of them, but there are laboratory tests that have been able to replicate the formation of very large waves in frequencies that can not be described statistically (i.e., exactly these freak waves). I will try to pull up a paper to help summarize modern “freak” wave research.

But one semi-side-note, the ocean is dispersive. This means that the waves of different wavelengths travel at different speeds. The speed of a wave crest increases linearly with wavelength, therefore the largest waves that avoid breaking from being too steep, will have a longer wavelength, and therefore travel faster than the other waves. This is likely why when a large, statistically-expected wave is experienced, they affect the vessel so much more: more velocity, and therefore more imparted momentum. Dispersion also explains why the first noticeable effect of a distant hurricane is the presence swells; swells out-run the other smaller waves, arriving first.

But this does not impact your article much, as you (likely correctly) describe that sailors may be wise to consider switching to a capsize-resistant storm method early on, and not to try to analyze the storm for big wave and therefore capsize probability. A freak wave, can not develop from benign conditions: they are created during stormy conditions where already large waves meet, in locations where they are constrained or modified by some factor, and become even bigger.

Cheers

Conor (PhD, Marine Physics, University of Miami)

Matt

Conor, I’ve read a few of the papers you’re talking about, and now I need to go track them down again. Good reading, for a physicist.

I’m reasonably confident in saying that:
1. “Rogue” waves (i.e. waves that do not nicely obey the usual 2nd-order partial differential equations, but instead invoke more complex nonlinear behaviours such as exchanging energy between interfering systems so as to become phase-locked for some time) do exist, they have been observed in the wild, and they have been numerically & empirically simulated in labs.
And
2. The waves sailors are talking about when they say “it was all fine until the rogue wave hit and everything went to hell” are, in virtually all cases, *NOT* those waves. Rather, they are (as John described) the extreme tail of a statistical distribution describing perfectly ordinary waves and their constructive/destructive interactions, and are therefore a normal, expected thing that you will encounter in gale-force or worse conditions.

Bottom line, I think John’s right that fretting about (or blaming) the “rogue” wave is unproductive in this context. Understanding what “significant wave height” means, with respect to the probability of encountering larger or smaller stuff, is important. Understanding the conditions that make it appropriate to switch strategies, and recognizing when that point is approaching before you actually cross it, is important.

Conor

Hey John/Matt

Yes, I think the article is pretty justified in saying that it is better to prepare for waves that are bigger than the waves one is currently experiencing. If it was me, I would probably not say “There are no rogue waves”, but I get the point that likely there are many stories of people who incorrectly claim a freak wave him them, instead of saying a large, expected wave him them. As usual, another great AAC article!
cheers
Conor

Conor

Forgot to link this:
It is an article by a captain that I did an atlantic crossing with that describes a rollover in a westsail 32 south of Australia.
http://www.westsail.org/Resources/Documents/Articles/Mike%20JohnsDismasting.pdf

and a 2nd-cup-of-coffee reading on rogue waves:
https://www.dropbox.com/sh/rp51j080dy0kxz9/AACaag6iCuZebTCTpN3CPx88a?dl=0

Stein Varjord

Hi John. I can’t add anything here, but I can give my view on a couple of issues. You say “As a card carrying coward with a well-developed fear of storms at sea…”. This is partly humour, of course. It’s also a simple and interesting topic. Someone who is about to jump out of a plane should be to some extent frightened, no matter how many times it has been repeated. Some degree of fear sharpens our awareness and gives us the ability to make it a lot safer. The fact is that jumping out of a plane will always be lethally dangerous. We still do it because we accept the statistical risk of death, and more importantly, because we have the illusion that our personal skills and attentiveness is so good that our personal risk is way lower. The latter part is silly, but more important: Not being frightened isn’t brave, it’s stupid. When cruising the oceans, the risk of lethal danger is extremely much lower than when jumping out of a plane, and the most probable lethal danger isn’t storms but falling overboard in normal weather, even close to shore. Still, a sailor who has experienced extreme weather will always fear it deeply. Again, any other attitude is just stupid. About the “rogue wave” topic, I’ve often thought that it sounds like a bad excuse for lacking awareness or just accepting a risk. A digression to illustrate a different type of attitude: My friend Are Wiig who recently retired from third place the Golden Globe Race after being rolled over in the roaring forties and loosing his mast says nothing about “rogue wave”. He just said that he’d been having really bad weather for three days and that it had calmed down a lot to just 40ish knots, so he found it worth a try to stop to repair his wind steering, again, as he was exhausted after so long time hand steering with no sleep. While working on it an “especially big wave” lifted the boat, turned it upside down and dropped it free falling many meters. He knew that these waves were around, but had to hope it didn’t hit. It still did. He didn’t have a JSD…. he didn’t complain and he didn’t ask for help, but closed the holes and cracks in the boat, tended to his wounds (he cracked the main hatch with his head), rigged a jury rig and sailed to Cape Town. He also wants to participate next time… Especially big waves, predictable or not, hurricanes, and similar should be seen as dangers similar to ground getting closer at an alarming speed. If we know we are falling, we can’t pretend that it doesn’t matter so much because the ground might miss us. If we’re at sea, those dangers do mostly miss us, but when they don’t, they have the same effect. As mentioned in other contexts, when the consequences are not acceptable, like death, our risk tolerance must move way… Read more »

db

Hello
an interesting article, but you allude to your preparation strategies without spelling out how you prepare. I think many readers would like hear your take on specific anti-capsize preparation.
thanks>
DB//

Brent

Jordan gives a good account of people in capsizes believing everything is O.K. until it happened and the resulting belief in a “rogue wave”. He says pretty much the same thing you state. The waves are steep enough that a boat can’t sail down them but rather falls off them generating huge forces that can roll or flatten the boat (from a fall on its side). The only solution is to cause the boat to slow down and best to use a mechanism that spans a few wave lengths so it can’t get pulled out of the water and can continue to act as a break – hence his design for the Jordan Series Drogue (JSD).

Having spent a nail biting watch helming a 53′ 18 ton boat accelerating from 9 to 14 knots in seconds surfing down 20′ waves in a Force 8 gale, I have an appreciation for how one of these could do significant damage if the boat were to turn or dig in its nose. In this instance, we were going down the east coast parallel to the Gulf Stream but in a southbound eddy with the winds on our tail and under bare poles except for about 2 square metres of unfurled Genoa to keep the boat tracking downwind (and on course). We were moving (perpendicularly) through a shipping lane at the time or we’d have heaved to or deployed the JSD (which we would have if it got any worse (winds were forecast to moderate back down to force 6 in the am)). The boat handled it beautifully and tracked in full control but it was clear that we all felt a hell of a lot better knowing we could deploy the JSD if things got any worse.

Jeremy Percy

Interesting thoughts and thanks for them. Having spent many years at sea as skipper on trawlers and tugs, it was “easy” enough to ride out bad weather by ‘dodge and lay’, not least as we always had a great big diesel engine to keep us straight into the waves, ahead or astern [less so in the latter]. Having moved to sailing, I would appreciate your view on the multitude of opinions on drogues v streaming warps. In a recent online piece related to the Golden Globe, RKJ was adamantly in favour of streaming warps rather than a drogue, not least due to the difficulties, dangers and time needed to retrieve one. I wasn’t sure whether he was advocating streaming heavy warps with anything attached as singles or in a loop?? Many thanks. Jeremy

Richard Dykiel

Another excellent article, breaking down hundreds of years of sailors lore into a rational approach.

David B. Zaharik

Wow, great article and great comments!

As a new to off-shore sailor, I need to hear this. It sounds like my reefing strategy. If I think I should put in a reef, (or my wife does), put it in before things get stupid. So putting in a 3rd reef around 30 kts should be a clue to drop a JSD! More to learn from Colin in the spring!

Mark Bodnar

I have a question – you reference the wave height as a percentage of the boats length (as does the article you referenced) – but the article also points out that the risk of end-over pitch poling is much less and the risk is mostly associated with being hit beam on.
My question is then why is the boat length relevant? Why not beam width? Is it because the average length to beam ratios are relatively similar?
It certainly makes much more sense thinking width rather than length. The idea that my 30ft boat could be rolled by a 10ft wave, and most certainly rolled by a 20ft breaking wave seems more intuitive given she’s only 12ft wide.

Bill Koppe

In 2002 I was returning from Hobart to Sydney and after a stop at Eden , headed north with a forecast of 25 knts. Around 12 we were getting 35 and it looked like getting worse, so we avoided the foul ground between Montague Island and the coast by going further out to sea.
This put us into a 5 knot adverse current and the Southerly built into an East Cost low which stayed over the 50 knots the B&G max. I was steering my 45 ft 20 t steel cruising yacht
Delta Wing which was an excellent sea boat.
By now the seas were extremely steep and I worried about falling off a wave.
Suddenly a wave came at right angle to the wave train and it picked up the yacht and threw it about 20 ft.
As it landed the pressure on my hands on the wheel became so painful I had to let go the wheel and she slewed to port as the next wave in the normal train picked her up sideways and I looked down around 30 ft and it was almost straight down.ie the wave was close to dumping. Having studied the excellent books on the 98 Hobart I headed back towards shore and once out of the current they were merely very large swells.
Had I stayed out in the current I would have either fallen off a wave or it would have dumped on the deck.
I would not have liked to be sitting there with a drogue .
The Hobart books show conclusively that the best tactic for the yachts was to continue sailing into the storm. This meant that they were out of the storm earlier whereas the yachts that ran with it stayed in the storm longer, as it worsened.

Eric Klem

Hi John,

You make a very good point that almost all of these incidents are likely not due to rogue waves and simply waves that should be expected with any real length of exposure. To me, this lines up reasonably well with casual observation too. When you are out on a sporty day where it is still fun, you get the bigger waves where you are glad that isn’t the norm but you also get an occasional one which makes you go yikes. Another eye-opening experience is to deal with the wind over tide at a bar crossing where in 100′, you can go from scary breaking waves to a pleasant day by simply ducking in and out of the current, it really shows just how important it is which I often don’t appreciate offshore.

I am also a wimp and enjoy reading about different accounts of survival and disaster. Most of my offshore work was done when I was an invincible age but I increasingly look at the incredible spread of conditions where boats have gotten in trouble and think yikes. Some of it is clearly the boat, some the crew, some probability but also there is definitely an element of windspeed and less-so wave height being poor indicators of actually how bad conditions are. Thankfully I don’t have the experience of ever being in a situation where survival was a real question but the occasional worse wave, helming mistake or similar has made me realize how much closer we were than I realized.

It also seems to me that our use of terms like gale has become problematic in some places. For example, tonight’s forecast where I am is 15-20 gusts to 35 knots (cold front coming through) and there is a gale warning up with the synopsis stating that there will be a period of “pre-frontal gale force winds”. To me, that either suggests that the forecast should be higher or that the definition of sustained winds versus gusts has changed.

Eric

Steve B

Hi John, I think of the readers/contributors of AAC to be in three categories: 1) Experienced sailors who can speak from VAST experience, 2) Sailors who know exactly what you are talking about but haven’t had their lives flash before their eyes, and, 3), me.

I am for intents and purposes, someone who has not been out of the mouth of the mighty Columbia River, but is someone who has not only dreams, but has a mind and strength of will to fulfill his dream to become the sailor who fits 1) aforementioned above.

With the disclaimer that my experience is limited to reading books and AAC, I want to pose the simple question: Does the Pardey bridle system make all of this a potentially non-issue as the slick will, in theory of course, eliminate the breaking waves (and thus the configuration of the wave becomes irrelevant)?

I have timidly brought up the Pardey bridle/slick in prior posts and would really, really love to hear the voice of experience resound again. Please advise, you sailors of the seven seas.

Steve Broom

Nelms Graham

The underling issue is today’s fixed keel sailboats and their propensity to trip over their own keels. I sail a one hundred year old design by Ralph Middleton Munroe, his Presto 36, a true centerboarder, with no stub keel. With its board raised she simply doesn’t have a problem with knockdown from breaking waves, Even with the board partially raised, a side strike from a breaking wave simply pushes her sideways, like the surf dories of old.

Dick Stevenson

Hi John,
There is the overall safety which you emphasize, but I would imagine (and I feel lucky to just imagine) that there is something to be said for the comfort level a JSD might achieve. It seems likely that a boat without much of a keel, would slip and slide around in a manner which could be quite fatiguing over time, perhaps even a danger to those inside the vessel.
My best, Dick Stevenson, s/v Alchemy

Marcus

I would have believed the no rogue wave idea except that during Hurricane Florence I was watching the live stream from the camera at the Frying Pan Shoals and twice in less than an hour I very clearly saw waves much larger than the current wave train moving at right angles to it. Do the people who say there are no rogue waves just lack observational data?

Michael Bowe

In regards to heavy weather sailing it seems to me that what we have is this: what we’ve read, what we’ve heard and what we’ve experienced regarding anything in life and heavy weather sailing. My experience with Huge seas took place in May of 2016 sailing from New Zealand to Fiji. I had found a Belgian girl to crew who was not a sailor but could cook, and didn’t get seasick! It was a difficult and tiresome 8day sail as we were on a beam reach almost the whole way. On the 7th day the wind and waves kept building. It was a mostly clear and sunny day and since we were getting close to Fiji the water and air temperatures were warming. I was sailing with a double reefed main only on my Rhumb line at about 60 degrees to wind and waves, in about 25-35knts of wind. The autopilot had quit several days before and the boat was being steered flawlessly by my backup Hydrovane which works best in high winds. It is called a Crush or Crunch Zone. The waves continued to get bigger and having sailed up and over these waves I sensed tha I needed more speed so I turned on my Yanmar diesel and was motor sailing at 6.5 Knots up and over these waves which keep getting bigger and bigger, finally reaching 10-12 meters. As an aside, I decided at this time that instead of panicking, I thought these waves were beautiful! Magnificent slow moving and mostly well behaved monsters! It was my incredible luck that my 60 degree angle to the waves was PERFECT! My Catalina 42 would work its way up a wave and I could look over the Lee side into a canyon! I realized that by moving forward at 6.5 knots, the momentum carried me up and over and prevented me from rolling down these waves! At the top, I could see for miles and noticed several “Rogue” waves in the distance, which I am convinced are waves within the statistical variation of the waves I was experiencing. Two of these waves that I sailed up and over had breaking heads, which I would say felt and looked like a four foot wave at the beach. One of them broke over my Bimini and cascaded through the cockpit. My reaction was to lay down flat and allow the wave to roll through. These waves lasted about 2-3 hours before diminishing, my Belgian crewmate slept through the whole ordeal! We reached Suva the next day. My take aways: ORIENTATION TO THE WAVES IS CRITICAL!!! Sailing down wind during these huge seas may have resulted in broaching (loss of control of steering) or pitchpoling! Which seems to lead to most calamities! Sailing on the beam is asking for a knockdown regardless of boat speed! Sailing or motoring directly into the waves is equally foolish as the possibility of falling back down a huge wave is unimaginable! SAILING OR MOTORING AT AN… Read more »

Rikki

The chunk of water that can pick you up and drop you down is not a rogue wave but a freak incident caused by counter acting forces in that specific location in a certain timeframe.
For those of us who have been in the situation where we look around us in awe and comment, “whew, glad we weren’t over there”, active avoidance comes into play.
If the conditions have rendered the crew incapable of active, alert sailing I would chose to set the boat up to sheer off the wind in the direction of diminishing pressure and rest in the cockpit with half an ear open. Most often there is a forewarning.
Rogue waves are not bad luck, getting caught by one is…
“Don’t tie me down.”

Following the condensed action in the GGR has brought to light some interesting reflections concerning the multiple dismastings. Looking forward to hearing the skippers renditions.

Robert

There is a new study (Dec 2018) publish in Journal of Fluid Mechanic’s, sharing the results of their study to replicate the Draupner Wave. This wave was laser measured at 25.6M in a 12M significant wave height conditions from an oil rig in the North Sea. At 2.13x SWH, it is on the upper edge of the maximum expected wave size. But as I understand it, what was really unique about this wave was not the height, but how steep the face was. Traditional thinking would have predicted a wave that steep could not exist, it would have broken and collapsed at a much lower height. Using a specialized wave tank they were able to replicate the wave for the first time by varying crossing angles (they recreated it at 120 degree cross). A summary of their conclusions from the abstract is:

“Using this capability, we recreate a wave of equal and greater steepness to the Draupner event with an equivalent surface elevation time series and demonstrate the directional conditions necessary for it to exist. In doing so, we also show that the breaking mechanism can be fundamentally altered in crossing seas: breaking no longer acts to limit amplitude in the same way, but results in upward, jet-like behaviour. We thus propose an additional fundamental process to be taken into account when seeking explanation of rogue waves in highly directional seas such as at Draupner: directional breaking for crossing seas.”

Link to the abstract and a free download of full paper can be found here:

https://www.cambridge.org/core/journals/journal-of-fluid-mechanics/article/laboratory-recreation-of-the-draupner-wave-and-the-role-of-breaking-in-crossing-seas/65EA3294DAFD97A50C8046140B45F759

The paper is quite technical. I don’t have a solid enough understanding of wave science to understand all the details, but find it interesting none the less, and thought others may as well.

Doesn’t change your overall conclusions of prepare early, but it is a new quantitative data set, accurately measured from a real world “rogue wave”, with laboratory confirmation of those measurements, and conclusions around the mechanic’s that lead to the formation, all conducted by expert wave scientists in a controlled environment. It provides a new perspective on what might be happening out there at any given moment of time that you aren’t expecting, and in fact was previously believed to be impossible. All the more reason to prepare early.

Stein Varjord

Hi Robert.
Interesting text. I’m also not competent enough to interpret the scientific language properly, but I already knew about the wave incidence since it was observed and measured from a Norwegian oil platform 24 years ago. Marintech at the university of technology in Trondheim did a much discussed study on it, without finding anything that could be used to understand it, but crossing wave trains were mentioned.

Some issues I find interesting in this report:
– The “wave-averaged free surface” goes down under a wave train, while with a crossing wave train, it goes up, increasing the measured wave top elevation, making it able to reach higher relative to a fixed installation like an oil platform, but not so with a boat.
– “The structural loads on the Draupner platform were much smaller than would be expected for such a large (non-crossing) wave.” This tells me that the wave itself probably didn’t move fast or far but was rather the momentary manifestation of wave interference/collision.
– “Breaking no longer acts to limit amplitude in the same way, but results in upward, jet-like behaviour.“ This confirms the impression of the previous point. This isn’t really a wave but a localised happening.
– “ A combination of a large winter depression and short duration ‘Arctic bomb’.” The arctic Atlantic (Southern Norway, but in the winter definitely arctic) has weather that is close to impossible most places on the planet. (As a side note: Very cold air is much heavier, thus contains accordingly much more energy. That makes a gale into an entirely (!) different beast. Yes, I’ve been shaken, and stirred. 🙂 Not recommendable…)

My not competent evaluations would be:
This wave seems to fit exactly what I observed in much smaller scale, wading and swimming at the north tip of Denmark 45ish years ago. (Described in a long post further up here.) These mini “Freak waves” seemed 3 or 4 times the height of the normal waves, but were not going anywhere. They just jumped straight up and disappeared. Apparently no power. I see it as the collision between two energy pulses. They cancel each other into not much energy, but some of it isn’t aligned and makes a splash, kinda like throwing a water balloon on a wall…

A 26 meter version of this type of wave would probably not be a nice thing to encounter, but its destructive force might be way less than it seems. More importantly, its seems very unlikely that normal long distance cruisers sail in conditions where a this type of wave on this scale is likely to appear.

So, my conclusion: I can’t see that I need to prepare for or fear this type of wave. I will, however, hope not to encounter one in real life….

Mark Bodnar
P D Squire

The sea is getting wilder, which gives import to this discussion.
“Extreme ocean winds and wave heights are increasing around the globe”*

Is it length or displacement that effects capsize resistance?
E.g. do you think that two 36 footers of 9 and 12 tonnes (loaded cruising weight) would be equally susceptible to capsize?

Would both be improved by stretching to 42′ (with commensurately reduced beam and hull-draft)? Thus stretched, would the heavier boat have the advantage?

*https://www.sciencedaily.com/releases/2019/04/190425143540.htm

Stein Varjord

Hi PD, I agree with Johns thoughts, but since I’m a nerdy nit pick, I have a couple of additional detail notions: As I understand your post, I would like to split your questions up a bit into these: 1. Will a boat be less vulnerable to capsize if it is lengthened while keeping all other proportions unchanged. Thus, a longer but relatively narrower boat, that is probably a bit heavier, but relative to its length, is lighter and floats higher. 2. Will a given boat be less vulnerable to capsize if its weight was increased without changing any other parameter? I can’t answer these questions with indisputable facts, but my strong conviction is that question 1 must be answered by a clear “Yes!” If the boat was not only lengthened, but evenly scaled up to a bigger boat, with the weight also scaled up, the improvement would most likely be even greater. For question 2, I need to split it into two scenarios, to give an answer I think is true: If the boat just gets heavier in a uniform manner, so it floats deeper but the stability is the same, the answer must be “NO!” Such a change would in my opinion make the boat clearly more vulnerable to capsize. If all the weight increase was in the keel, thus increasing the boat stability, the answer is probably “yes”, it would have a bit more resistance to capsize by waves, but perhaps not always and not with any level of weight increase. A certain boat design fits a certain weight. Some designs are fairly tolerant to weight changes, others quickly get major problems. Designers put a lot of attention to where the waterline is. The hull is shaped with that line as one of the most important factors. In general, changing a boat in its fundamental properties, like weight, is not a straight forward issue. However, improving stability by removing weight aloft, like changing to a carbon mast and getting rid of rubbish in the rigging, has far superior effect compared to adding weight to the keel. When I say “rubbish in the rigging”, that’s harsh words to get the attention towards all the stuff we put up there and how much it influences our boats’ properties. Just weigh one of the halyards you have. Do you really use all of them? That stainless steel antenna platform at the mast head, have you checked what it does to your stability? I can promise that if you get a qualified engineer to look at it, you won’t like the answers. An example: In the eighties, the Norwegian King was making a serious effort for the IOR One Ton World Championship, which at the time was only second to The Americas Cup in competitive big boat racing. They were looking at every little detail of every aspect. Two of the crew were people I sailed with often, so I got much interesting knowledge there. One detail that caught public attention… Read more »

Stein Varjord

Hi John,
Again, I agree with every word.
My post above was initially meant to address an idea I’ve frequently heard, that a heavier boat is safer, just as a function of its weight, which I feel is usually quite the opposite.

I then went on to discuss details of the issues in a way that might indicate that I believe in optimising the boat to avoid big wave capsize. I don’t. I really think most boats can be improved quite dramatically by looking at the right details. That’s fascinating and can be great for everyday boating life, but those improvements are almost irrelevant to avoiding capsize by waves. Sorry for the distraction. My theoretical detail focus does indeed risk removing the attention from the real issue:

Any boat, no matter how well designed, prepared and handled, can be capsized by the right circumstances. We all need a strategy suited for the boat, crew and situation to overcome that problem. For any realistic long distance cruiser scenario, the core of that strategy should be a JSD.

Colin Palmer

Looks like the waves are getting bigger with time:

https://tinyurl.com/yyjqnfl8

“Their study found that the largest rises have occurred in the Southern Ocean and also that the magnitude of extreme wind and wave events (those in the 90th percentile) have increased significantly.” and

“Extreme wind and waves
Their work reveals that these waves, and the winds that generate them, are increasing in magnitude and have been doing so for the last 30 years on a global scale. Furthermore, the study shows that extreme wave conditions are increasing even more rapidly – with the largest increases occurring in the Southern Ocean. Indeed, extreme winds in the Southern Ocean have increased by approximately 5.4 km/h or 8% over the past 30 years. Extreme waves in this region have increased in height by 30 cm or 5%. In general, the study found that winds are increasing at a faster rate than wave height.”

Marc Dacey

Very interesting. Some people are surprised when I comment that my high school math and physics course have found application in sailing, and math and physics continue to contribute to our knowledge of the sea.

Whitall Stokes

Hi John,

Terrific analysis. I recall reading something that discussed the treachery of cross-seas causing enormous unexpected energies. Cross seas causing potential for highly irregular and large seas that must be planned for and accommodated. I would guess these are experienced in the High Latitudes as the low pressure systems rotate around. This would make the backside of low pressure systems particularly dangerous, just when skipper and crew are tired, of course? I wonder if it makes sense to weave this concept into the chapter somehow?

Whitall

Wilson Fitt

Hi John

I just returned this week from a passage from Nova Scotia to Portugal aboard a well-found 56 ft boat, following a great circle route that took us up near Newfoundland, across the southeast corner of the Grand Banks and well north of the Azores. All went well due in large measure to good weather information from Predict Wind. About half way between Newfoundland and the Azores, well out in very deep waters, we had more than a day’s worth of east setting current running as much as two knots with patches of chattering little waves, small whitecaps and very distinct transition lines just like you see in inshore tidal currents. This was no doubt a far reaching branch of the Gulf Stream. The wind was light and the favourable lift was welcome, but a moderate easterly gale against that current would have set up a fearsome sea with “rogue waves” a distinct possibility. This reinforces your message that potentially dangerous wind against current situations can be encountered in unexpected times and places, not just in the Gulf Stream and similar well known risk areas. Be prepared for surprises!