New Imoca's

Tried to attatch a vid but dosnt want to do it. Google Imoca Charal if you are interested.

looks like the rudder and associated bits will take big hits !

I believe the noise inside is what causes the most stress and exhaustion.

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SandS said..
looks like the rudder and associated bits will take big hits !

I think I read that some boats are carrying spare foils this time. No idea how you'd change one in big seas. Last time Thomson broke one off (shipping container I think) and was fast on one tack and slow on the other without the foil. Amazing boats.

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2bish said..
120dB.... man! that's a chain saw at full tilt less than one meter away, I'd be wearing my noise cancelling headphones the whole time.

I slightly exaggerated. It varies between 90 and 120 dB: www.vendeeglobe.org/en/news/16517/ear-flaps

Still very unpleasant.

.

And if you ever needed justification for a three point tether with a short strop....
That toe rail looks awfully important all of a sudden!

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shaggybaxter said..
I often wonder if the Volvo boys look at the Imocas and grind their teeth for the Imoca's traits on protection from the elements. I get that you can't do this on a fully crewed boat, but man, I know which one I'd rather do the Southern Ocean in.

There was an interview with David Witt I saw. They asked him Volvo or Imoca. He said Imoca. Going around the world on a Volvo boat is like someone spraying you with a fire hose any time you go on deck.
The Corum boat is launched now and there are some great articles about it. It's very different again. Scow bow. The foils are quite high on the top sides too.

www.imoca.org/en/news/news/three-fighter-planes-and-some-breakage

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JakeNN said..



Does it get planing? Wouldn't it be nice to get planing, switch on the auto-pilot and enjoy the ride with a beer?

Probably a better question for ShaggyB!

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JakeNN said..

wongaga said..
I love my nice semi-full keel 55% ballast ratio, 14 SA/D old man boat!
Cheers, Graeme

Just keen to learn here ... What is a semi-full keep 55% ballast ratio, 24 SA/D?

Does it get planing? Wouldn't it be nice to get planing, switch on the auto-pilot and enjoy the ride with a beer?

Hi Jake,
The ballast ratio is a percentage of the ballast compared to the dry weight. The higher the number, the more ballast is carried compared to the overall weight, which means more resistance to heel. Graeme's 55% compared to my 36% means as the weather gets a bit fresh Graeme is enjoying a nice cup of tea with full sails up as I am scrambling to downsize sail area to keep the boat on her feet.
The SA/D is a comparison of your total sail area to your displacement. Upwind I run a SA/D of 34'ish, downwind it jumps to about 65. Graeme's SA/D of 14 means as the weather gets fresh he is now enjoying a nice nap after his cup of tea, still with full sails up, as I am hanging on grimly as the boat charges off like it's been possessed . We start planing at about 15kn TWS and as the wind comes behind about 80 deg TWA.

To answer your question, yes its the best feeling in the world to sit back when the boat is trimmed, on the plane and it' s effortlessly soaking up miles. For Fusion, the lower ballast ratio is offset by a wider beam which lends a lot of hull form resistance to heeling, so gusts tend to be soaked up by the hull shape rather than put you over on your ear. That sort of thing isn't reflected in your SA/D or Ballast ratio, which is why there is a bazillion other calcs naval architects use to typify a boats manners.
So while a higher SA/D is enormously rewarding, you can't be lazy. Speed is fun, but if the comfort level goes way down to achieve this it gets a bit naff pretty quickly.
To apply this to the real world... Graeme and I are headed for same harbour and its been a bit fresh. Graeme may get their a tad later but he'll be dry, comfy, sporting a big smile and a hairstyle like he stepped out of Vogue magazine. I might get there a bit quicker, but I'll be soaked, tired, counting bruises, sporting a HUGE smile and a hairstyle like I stepped out of Just Mechanics.
Cheers!
SB

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shaggybaxter said..

JakeNN said..

wongaga said..
I love my nice semi-full keel 55% ballast ratio, 14 SA/D old man boat!
Cheers, Graeme

Just keen to learn here ... What is a semi-full keep 55% ballast ratio, 24 SA/D?

Does it get planing? Wouldn't it be nice to get planing, switch on the auto-pilot and enjoy the ride with a beer?

Hi Jake,
The ballast ratio is a percentage of the ballast compared to the dry weight. The higher the number, the more ballast is carried compared to the overall weight, which means more resistance to heel. Graeme's 55% compared to my 36% means as the weather gets a bit fresh Graeme is enjoying a nice cup of tea with full sails up as I am scrambling to downsize sail area to keep the boat on her feet.
The SA/D is a comparison of your total sail area to your displacement. Upwind I run a SA/D of 34'ish, downwind it jumps to about 65. Graeme's SA/D of 14 means as the weather gets fresh he is now enjoying a nice nap after his cup of tea, still with full sails up, as I am hanging on grimly as the boat charges off like it's been possessed . We start planing at about 15kn TWS and as the wind comes behind about 80 deg TWA.

To answer your question, yes its the best feeling in the world to sit back when the boat is trimmed, on the plane and it' s effortlessly soaking up miles. For Fusion, the lower ballast ratio is offset by a wider beam which lends a lot of hull form resistance to heeling, so gusts tend to be soaked up by the hull shape rather than put you over on your ear. That sort of thing isn't reflected in your SA/D or Ballast ratio, which is why there is a bazillion other calcs naval architects use to typify a boats manners.
So while a higher SA/D is enormously rewarding, you can't be lazy. Speed is fun, but if the comfort level goes way down to achieve this it gets a bit naff pretty quickly.
To apply this to the real world... Graeme and I are headed for same harbour and its been a bit fresh. Graeme may get their a tad later but he'll be dry, comfy, sporting a big smile and a hairstyle like he stepped out of Vogue magazine. I might get there a bit quicker, but I'll be soaked, tired, counting bruises, sporting a HUGE smile and a hairstyle like I stepped out of Just Mechanics.
Cheers!
SB

Good writing SB - got a kick out of reading it