HMS Otago in Southern Ocean

[wheels 543]

Dec Last year. Apparently 80knts of wind and 15m seas.
https://assets.stuff.co.nz/video/production/1464583328106-Southern%20Ocean%20Storm.mp4
 

[Island Time 1,239]

Rough seas, for sure. But does not look like 80 knots to me - not enough spume. Although the perspective is different from a ship, it seemed to me in those wind speeds the breaking white water is blown away, and the sea surface looks white and smoking.

[Black Panther 1,592]

Wonder what the height of the bow is?? Those were a couple of BIG waves.

[ex TL systems 63]

good to see when you are getting a boat ready for offshore, you can do a lot or miles and never see that, those breaking waves are where you would want your sea anchor to be strong if you choose to deploy one and your boat to be solid, or if its the right direction you may choose to go with it and tow whatever you have to control the surfing, that may get to be hard work though either way better to be somewhere else.

[Freedom GBE 27]

 be somewhere else.

Predictwind and fast boat might be my preference to a steel grader with a large sea anchor. I am sure Vodafone wouldn't fear too well in a waves like that but then she can out run a storm.

[erice 732]

hmmm.......

 

didn't she have to hang around, taking a battering

 

off sydney a few years ago

 

because there was no where else to run to?

 

edit

 

A complex low pressure system over the Tasman Sea last night produced 50-knot winds and four-metre swells off the coast of Sydney, forcing the crew of the 60-foot trimaran to endure a rough night at sea waiting for the storm to pass.

 

http://www.sailsmagazine.com.au/j/index.php/livenews/136-TeamVodafoneSailing-battling-the-storm

[SthnJeff 18]

Looks like a sail across Wellington Harbour in moderate winds. 

[wheels 543]

I agree that the Vid is not showing 80kts of wind. Either that, or we were in over 80kt, because the water simply whipped into white misty spray for us. It also isn't 15m seas. I have been in 10m on the Ferry and the crests of those things were above us. When in that wave height in our own boat, I remember motoring up the face and looking down behind us and thinking the Crest was still to come, we are 14m and the trough was way below, how the hell big are these things.
But that is not to say the Otago did not experience that kind of storm. I just don't think it is in that Vid.

[B00B00 310]

That is plain terfying... Any yacht caught in that wave would be in big trouble.

[Island Time 1,239]

Ok guys, here is a question for you. What size do you think the breaking part of the crest of that big breaker is? Remember that the ship has dipped her bow into it - sort of scooped it up...

[wheels 543]

Well from deck to top of flared spray deflector around the bow is about shoulder height, so at a guess about 1.5m. That wave crest had to be 2.5m above that spray deflector. That puts the cresting part at 2.5 to 3m depending on where you want to measure. I would say the entire wave was about 8 to10m. The Bow must have buried itself to about anchor height up from normal waterline. I guess the bow peak would be 7 to maybe 8m above waterline.

[Island Time 1,239]

Interesting, and it is known it is very hard to estimate waves just by looking. I would have said a bit more than that myself. I thought about 4m or so of breaking crest.

Research has shown a 4m breaker can roll a 40ft 12m vessel....

Good to avoid!

[ex TL systems 63]

seems that it broke right in front of them, and maybe 3 or 4 m when it broke but looking at the rest of the waves it seems that it would have dissipated fairly quick, hanging on a sea anchor would not allow you to avoid those breakers , just hope the boat will r go over the white water or survive going through it. Reading some books would suggest an oilbag out in front of you maybe on the sea anchor rode may help to stop waves breaking by making a slick on the surface?

[Island Time 1,239]

In my experience on a parachute in seas like that, the waves break over the parachute, or just past it, and the force is mostly dissipated before it gets to the boat. If not, the parachute should pull the boat through the crest, bow first, or a bit of an angle if on a bridle.

Looking astern, down the waves from the crests, I was happy not to be trying to sail down wind ????

[Black Panther 1,592]

Running with a drogue something similar happens, I was astounded at not being hit, just backing quietly through the wave.

[wheels 543]

 

Interesting, and it is known it is very hard to estimate waves just by looking.

Yes I agree. And wave height doesn't tell the whole story either (as you experienced guys already know). . Those waves seem to be close together. That would be nasty in a smaller vessel.

      I doubt the Otago would have been steaming full on into that stuff, but she seemed to be getting through the sets quickly. So the waves can't have had a lot of distance between each peak, which also tells me they are not as high as the report says. The cresting wave was what is called a "freak"wave. Hence it's shape, height and short duration. You can see how it forms in the Vid. The wave immediately before it collapses it's energy. Hard to see, but you notice the water around that area goes all weird and flat and the spume on the water surface ( which is showing the water movement) actually runs opposite direction toward the cresting one. I watched that part  several times and then suddenly noticed all the bits of ice in the water. Did anyone notice that?

By the way, as as Ships go, Otago is not large. She is only 96m long and 14m wide. If you use the width of 14m as a bit of a guide, once again, that ells me those seas are not the height reported. I would say that this was the early stages of a building storm. If it was afterwards and the Sea had been at 18m and this was as the Wave height was dropping again, the Wave period would be much much longer. Well, that the way I see it anyway.

[rigger 47]

Picture and video can be deceptive.

 

Looking at the image below take a guess what the wave height that was recorded that day both avg and max at the time.

 

 

 

[wheels 543]

Perspective, if I am using the right word, or where you are on the Boat can make a big difference too. If I am down in the Pilot house, the waves can look big and intimidating. But if I get out on the rear deck steering position, I am 1.5m up higher than down in the Pilot hose and thus looking from a different perspective and suddenly the waves don't seem as big and you fell much happier being in stuff.