Cat in 10-15' seas with around 3-4 second period

[Dockhead]

Originally Posted by Kenomac

It's been explained many times on this forum how the Beaufort scale can't be applied to seas such as the Mediterranean and Baltic or even the Great Lakes. We certainly get the high winds, but the corresponding sea state is different from the Beaufort scale, instead we get steep high waves with a short period between them.

Ken is right -- the sea states described in the Beaufort scale are for fully developed ocean waves, blowing across thousands of miles of fetch for long periods of time.

You get very different sea states in smaller bodies of water like Med or Baltic, much less wave height, but shorter periods.

Up to the point where the ocean waves start to break, I think they are actually easier to deal with than the Med/Baltic ones, even though the ocean waves can be much higher for a given wind strength. I actually had part of my rail broken off my boat in a F8 crossing between Sweden and Finland this year, on a reach no less, not bashing into the waves. They were so steep that they were smashing violently onto the deck, but they were not high at all, I would say 3 meters or so, 4 at most. Never get that in an F8 in the Atlantic.


Also a given wind speed, whatever the body of water, won't produce fully developed wave trains instantly -- it takes some time. It it only blows for an hour or two, it won't get enough energy transferred into the water to get the sea up.

[Kenomac]

Originally Posted by Snowpetrel

^^ utter rubbish

Sent from my SM-G930F using Cruisers Sailing Forum mobile app

Here in this video is 6-8ft steep choppy waves formed by 35 knot winds from a building mistral. If and when the wind increases to 40-45 knots, you would see the 10-12ft steep choppy waves in the catamaran video with the same 4-5 second intervals. Maybe only 200 miles of fetch off the French coastline. If you like, I can show you a second video of us heading the opposite direction the next day with 40 knots behind us with the waves having built up to 10-12ft.

If you don't believe me, come over to the Med and see for yourself. 10-15ft steep waves with short intervals in 40-45 knot winds is not uncommon. Or just look anywhere along the Mediterranean coastline and you'll see all the vegetation and soil washed clean off the rocky coastline for the first 30-40ft of elevation off the water.

https://m.youtube.com/watch?v=_f4Wf0qDdbs

[rognvald]

Originally Posted by Kenomac

It's been explained many times on this forum how the Beaufort scale can't be applied to seas such as the Mediterranean and Baltic or even the Great Lakes. We certainly get the high winds, but the corresponding sea state is different from the Beaufort scale, instead we get steep high waves with a short period between them.

Ken,
I won't argue with your above statement, but the sea state pictured in the above video of the Aegean does not even come close to a 10-15 foot wave train. And, the sea state appears to be closer to a 30K blow . . . but not 50K. As far as the Great Lakes, a 30-35K continuous wind(one day) blowing up/down or across the lakes during the Spring/Summer/Fall will produce seas of 10-15 feet with a short fetch and nasty breaking conditions. During the Winter with 30-50K, 18-22 foot seas are common and would not be survivable by a small boat sailor. I believe many sailors tend to exaggerate winds and sea state and ,in all fairness, they are difficult to judge when you're in the soup. Good luck and safe sailing.

[Dockhead]

Originally Posted by rognvald

. . . As far as the Great Lakes, a 30-35K continuous wind(one day) blowing up/down or across the lakes during the Spring/Summer/Fall will produce seas of 10-15 feet with a short fetch and nasty breaking conditions. During the Winter with 30-50K, 18-22 foot seas are common and would not be survivable by a small boat sailor. I believe many sailors tend to exaggerate winds and sea state and ,in all fairness, they are difficult to judge when you're in the soup. .

I've heard this before about the Great Lakes. I've sailed extensively in Med and Baltic, but never in the Great Lakes. I wonder why it would be so different? Because of fresh water? Bottom contour? Perhaps the temperature also plays a role -- cold air is denser.

I've never seen 6 meter seas in Med or Baltic, and I've been out in some way nasty weather in both.

[Kenomac]

Originally Posted by rognvald

Ken,
I won't argue with your above statement, but the sea state pictured in the above video of the Aegean does not even come close to a 10-15 foot wave train. And, the sea state appears to be closer to a 30K blow . . . but not 50K. As far as the Great Lakes, a 30-35K continuous wind(one day) blowing up/down or across the lakes during the Spring/Summer/Fall will produce seas of 10-15 feet with a short fetch and nasty breaking conditions. During the Winter with 30-50K, 18-22 foot seas are common and would not be survivable by a small boat sailor. I believe many sailors tend to exaggerate winds and sea state and ,in all fairness, they are difficult to judge when you're in the soup. Good luck and safe sailing.

It appears we agree on most everything. I also don't see much wind driven spray in the Aegean video, they may have been referring to wind gusting to 50k. There might be some misunderstanding as I was referring instead to the original catamaran video posted by the OP. Not the sea state in the Aegean video.

[CbroTheDude]

Originally Posted by 44'cruisingcat

That's basically what this forum consists of. A very few sailors posting their experience, and an awful lot of keyboard sailors (the kind of people who don't say what boat they own, because they don't own one) criticising everything they do.

Rich people can be sailors or at least have a boat which doesn't make them anymore clever than people sailing but who can't own their boat...
Stupid harsh stereotypical comment, and you look more like what you call a "keyboard sailor" than anyone with such unjustified intolerance

[downunder]

Originally Posted by CbroTheDude

Rich people can be sailors or at least have a boat which doesn't make them anymore clever than people sailing but who can't own their boat...
Stupid harsh stereotypical comment, and you look more like what you call a "keyboard sailor" than anyone with such unjustified intolerance

Now thats an interesting observation of someone who built their own vessel (catamaran) including their mast and living aboard full time for 12 mths a year for years now.

You could not be more wrong in this case Dude.

[rallyman1122]

Originally Posted by CbroTheDude

Rich people can be sailors or at least have a boat which doesn't make them anymore clever than people sailing but who can't own their boat...
Stupid harsh stereotypical comment, and you look more like what you call a "keyboard sailor" than anyone with such unjustified intolerance

I think you ought to do a bit of research there, my friend. The person you are so quick to be critical of is one of the more respected members here.

44C has been there and done that and speaks from experience. Something you appear to not yet have aquired

[moepitman]

Originally Posted by Dockhead

Ken is right -- the sea states described in the Beaufort scale are for fully developed ocean waves, blowing across thousands of miles of fetch for long periods of time.

You get very different sea states in smaller bodies of water like Med or Baltic, much less wave height, but shorter periods.

Up to the point where the ocean waves start to break, I think they are actually easier to deal with than the Med/Baltic ones, even though the ocean waves can be much higher for a given wind strength. I actually had part of my rail broken off my boat in a F8 crossing between Sweden and Finland this year, on a reach no less, not bashing into the waves. They were so steep that they were smashing violently onto the deck, but they were not high at all, I would say 3 meters or so, 4 at most. Never get that in an F8 in the Atlantic.


Also a given wind speed, whatever the body of water, won't produce fully developed wave trains instantly -- it takes some time. It it only blows for an hour or two, it won't get enough energy transferred into the water to get the sea up.

I've seen the same in the Gulf of Mexico, though the water isn't as pretty. 10 to 12 feet in well under 40 knots, with a nasty, short period.

[Littlechay]

LOL.. yea I think these guys have their meters calibrated in kilometers per hour

As for the comments on Beaufort sea states. With new winds the seas can be completely flat and as others have said the waves build over time. The seas can only reach their full height with sufficient fetch. However the description of the surface of the water; blown streaks, spray, etc.. hold true at any point of the blow's development.

People often quote the highest gust they see as the wind speed .. it aint!

Their anemometers are invariably not calibrated for the height of the sensor on the mast.

Then there is just pissing contests.

Whatever the wind that cat is is nasty sea. Looks like there is sea reflected off the harbour wall mixed up in that too. Wouldn't fancy doing a pick up off a pilot ladder in that.

[Jim Cate]

I wonder if the reported 3-4 second period takes into account that the boat is moving towards the wave motion, and at a significant fraction of the wave train velocity? The resulting Doppler effect will shorten the apparent period considerably; this could help explain some of the conflicting thoughts above.

Jim

[CbroTheDude]

Originally Posted by downunder

Now thats an interesting observation of someone who built their own vessel (catamaran) including their mast and living aboard full time for 12 mths a year for years now.



You could not be more wrong in this case Dude.

I was only following your description of CF members, in which your primitive close-minded criticising speech puts you more in the keyboard-sailors category, so maybe you're wrong ;-)

[Littlechay]

Originally Posted by Snowpetrel

^^ utter rubbish

Quite!

[SVNeko]

Originally Posted by CbroTheDude

Rich people can be sailors or at least have a boat which doesn't make them anymore clever than people sailing but who can't own their boat...
Stupid harsh stereotypical comment, and you look more like what you call a "keyboard sailor" than anyone with such unjustified intolerance

You're making friends here everywhere you go.

[Suijin]

Originally Posted by Jim Cate

I wonder if the reported 3-4 second period takes into account that the boat is moving towards the wave motion, and at a significant fraction of the wave train velocity? The resulting Doppler effect will shorten the apparent period considerably; this could help explain some of the conflicting thoughts above.

Jim

Indeed, that boat seems to be making consistent headway, so the actual wave period could be substantially longer.

Looking at the video there are a couple of things that are immediately obvious. First, it's a big boat. Second, some of the swells are indeed 10'-15', with the cabin top vanishing as the boat slips into the trough (and the vantage point of the video is elevated. And the general wave period is pretty short, even if the larger swells are spaced further apart.

This was probably filmed in the Med, since the poster is Greek and has posted a number of other boat videos of generally similar conditions shot locally.