Rogue Waves

[John Stone]

Interesting article on rogue waves. Not something I like to think about....

https://getpocket.com/explore/item/the- ... ket-newtab

[Jim Walsh]

On 7/1/15 I was caught in a full gale 200 NM southeast of Noank when returning from Bermuda. It didn’t take long for the seas to increase dramatically. I estimated, conservatively 18 to 20 feet, but every once in a while throughout the duration the rigging would hum and I could hear the low roar of a big one approaching. A few times I looked out the ports and it was like being in a aquarium with green water flowing off the deck after a wave top broke beside me. I was very happy to have a cutter rig with 11 stays to keep the rig intact and the build quality of out boats to depend upon.
My self steering vane paid for itself that day. I was able to tend ship, adjust sail, and keep safe below with regular visits topside to check on things till the storm blew out. In 22 hours I managed to cover over 90 NM with 30 sq. ft. of the yankee only. This gale blew out of the southwest and I had the Gulf Stream in my favor.

[ghockaday]

That's an impressive wave Jim!

[tartansailor]

"Heavy Weather Sailing" by K. Adlard Coles is a white knuckle read on the subject.
In the end he gives advice on dealing with the worst possible conditions, and still survive.
Dick

[John Stone]

That’s a great book Dennis.

The rogue wave theory is real. We are not talking about every seventh wave or every third or fifth set being bigger than the average wave height. Nine of my 26 years in the Marines were spent in reconnaissance units. Hydrographic surveys and surf reports for amphibious landings are part of the mission requirement. So I spent some time learning about wave theory and watching and recording wave heights etc. While such experience has been very beneficial to me when making surf passages in dinghies that’s not what this is about. Rogue wave theory is about substantially larger waves that occur when waves, often from slightly different directions, briefly align and gain sudden and significant height for a very short period of time. Maybe just seconds. These can’t be predicted. I have read that submerged mountain ranges and even small single peaks many thousands of feet below the surface can also influence the height of waves passing overhead. Hal Roth and Larry Pardey wrote about this and always made a point of paying attention to hydrography when developing course lines so as to avoid passing over these dangerous features offshore, especially in bad weather.

Small boats can be literally swallowed and vanish without a trace if they are hit by a large rogue wave. On the other hand I think these really huge waves don’t last long. And you have to be in exactly the wrong place at the wrong time to experience one. At least that’s what I tell myself when I am laying in my bunk at night offshore in a rising wind and building sea....

A big part of offshore sailing is fear management.

I attached a photo I took running down wind maybe 100 miles on the east side of the Gulf Steam in a gale in early Dec 2018. All I had up was a double reefed stays’l. It was scary. I estimated this wave as close to 18’-20’ high. It’s so hard to tell though. Like Jim’s picture, photos just don’t capture the size of waves. I can’t imagine seeing 40’+ waves.

[fmueller]

Never sailed in anything like that ... 6' maybe in Jerezana south of Newport ... 10' in my Dads Hinkley (42') many years ago at night south of Monhegan island headed for Cape Cod and the islands. Oddly my boat is so small (and heavy) that crest to crest distance in a freshening breeze build well past boat length quickly and the pounding stops ... I sometimes think its a smoother ride than my Dads boat was on a lively day ...

I envy you guys with cutter rigs ...

Went deep sea fishing once out of Barbuda north of Antigua ... 6 meter seas from three days of 25 knot trades from the east ... 40 ft sport fisher ... in the troughs could not see over the crests from the fly bridge blew my cookies after about three hours. It was miserable and stupid to have gone out.

[Steve Laume]

It's not so much how big the waves are as it is their steepness. Huge rolling waves are never a problem. Steep sharp waves that have reached their breaking point are what you need to be concerned about.

I feel much more discomfort than fear when sailing in rough conditions, wherever they may occur, Steve.

[John Stone]

It's not so much how big the waves are as it is their steepness. Huge rolling waves are never a problem. Steep sharp waves that have reached their breaking point are what you need to be concerned about.

I feel much more discomfort than fear when sailing in rough conditions, wherever they may occur, Steve.

I agree Steve. I think that’s generally true. Breaking waves are a whole other animal. But I have read several studies that suggest monohull boats can be rolled in wave heights just 1.5 times a boat’s beam width. That would suggest 16’ waves on the beam could in theory roll a CD 36. There may be other parameters that play into such a result but I am careful in big beam seas. Even if not rolled you can certainly get knocked down.

Obviously point of sail makes a big difference. In Dec 2015 I sailed for about four days in reinforced trades from 26°N to 19°N with gust to 35 kts mostly on a beam reach. We had some big waves. Some I am certain reached 20’. I never felt worried but I was very attentive. I felt mostly tired. As we approached the BVI and I could foot off to a broad reach the change in ride was astonishing. I have some great video of those beam seas I’ve been meaning to put together and post on our channel.

Obviously point of sail makes a big difference. Running down wind in these conditions, at least for the FR and me, is quite comfortable. Never got pooped. Deck mostly dry.

Still, an unseen serious rogue wave...I shutter to think of the havoc that could befall a small boat offshore.

[Steve Laume]

The worst experiences I have ever had with waves, have mostly been within sight of land.

I have had extended periods of beating into waves while off shore. I also had one wave knock me over pretty far while I was down below, in my bunk. I have feeling it broke, right up against the side of Raven from the sound it made and what it did to us. I got pooped, twice, in succession, when in a tidal race. The stern wave just piled up and come right over the stern to fill the cockpit. I have also buried the bow on one occasion. It is still the really steep waves that make life most miserable. I have been in huge seas that look scary but the boat always rises up and over them.

Rouge waves may be more common than once thought but they are still extremely rare.

Carl seems to have known what he was doing, Steve.