IACC Boat speed at 30 degrees heel?
 

Nav wrote
I guess you would not have overtaken the race leader -look at this:


http://www.sevenoceans.com/SoloAroun...Leg1/Day30.htm

Great pics. But again.. a special case. Those boats are more like scows.
Besides, for publicity shots they like to heel the boats 'way over. And
the boat in the top pic is certainly not heeling at any great angle. I
guess you have to be *very* selective in choosing examples that support
your contention?

Fresh Breezes- Doug King

IACC Boat speed at 30 degrees heel?
 

Nav wrote:
Wrong again. Look at the references.

OK, I bow to your greater experience with googling and bookshelf
sailing. Heel your boat to 30 degrees all you want, it's fun. Who am I
to try and convince you to look around in the real world?

DSK

IACC Boat speed at 30 degrees heel?
 

DSK wrote:

Nav wrote

I guess you would not have overtaken the race leader -look at this:


http://www.sevenoceans.com/SoloAroun...Leg1/Day30.htm



Great pics. But again.. a special case. Those boats are more like scows.
Besides, for publicity shots they like to heel the boats 'way over.
And the boat in the top pic is certainly not heeling at any great
angle. I
guess you have to be *very* selective in choosing examples that support
your contention?


No, these boats are faster at 30 degrees of heel when beating as I keep
saying. Are your seriously suggesting you are a better racer than
Thiercelin who talk about being at a permanent 40 degree heel?

You are dead wrong on this one -admit it.

Cheers

IACC Boat speed at 30 degrees heel?
 

Nav wrote:
Bluster all you like but 30 degrres for max boat speed is still quite
usual.

So far, you seem to be talking about IACC boats and 'Round-the-world
racers.... now you're generalizing to all boats? These are pretty
specialized designs.

Find a quote from a racing skipper who says specifically, "Yes, we won
because we kept the boat at 30 degrees heel and more." Then maybe you'll
have something. If you are a member of a sailing club you can ask
around... oh wait, that's in the real world...

For the following quote, I'll give you 2 points (although Bart is the
official scorekeeper, he'll have to verify it) it still proves nothing
about the way 'most boats' sail IMHO.



....While a canting keel increases stability (or righting moment)
dramatically under

typical sailing conditions (say 30 degrees of heel),

its offset CG actually works against a self-righting tendency at large,
knockdown heel angles.

True because the canting keel will have similar CG geometry to a dinghy
with a hiked out crew... oops wait...

.... Accordingly, Volvo 70 Rule developers have
closely examined limitations on hull displacement and beam that affect
form stability, with additional limitations on keel weight and keel
swing angles. Each yacht shall have a designer-calculated limit of
positive stability greater than 115 degrees, with appendages positioned
in a worst-case scenario. In addition, each boat must successfully
self-right from a 180-degree inversion using only manual power to
articulate the keel."

This is rather ironic, Navvie, they are talking about LPOS not max
speed. Another oops?


http://www.perrottidesign.com/new_Volvo_Open70.html

Anyway thanks for the link. Cool pictures, I am looking forward to
seeing more forward-foil boats sailing.

Fresh Breezes- Doug King

IACC Boat speed at 30 degrees heel?
 

Nav wrote:


DSK wrote:

Nav wrote:

Have you done any big boat sailing or been in a race in windy
conditions?



Why, of COURSE not, Navvie. Never!


Well it's good to know my suspicions were correct.

Just as correct as most of your other assertions.



So you're saying that you base your judgement solely on what you've
read in books?


It was you that was seeking references wasn't it? Don't you like
definitive references that support my views? How strange. Perhaps you
are the sophist Jax suggested?

Because I show that you are wrong, does that make me evil or sick in
your opinion? Besies, if I am as stupid as you say, then I could not
have the intelligence & subtlety to be a sophist.

DSK

IACC Boat speed at 30 degrees heel?
 

Nav wrote:
No, these boats are faster at 30 degrees of heel when beating as I keep
saying. Are your seriously suggesting you are a better racer than
Thiercelin who talk about being at a permanent 40 degree heel?

Key- 'these boats'

You keep picking expamles of extreme type and saying this is how normal
boats sail.


You are dead wrong on this one -admit it.

Nope, so far you have provided some interesting pictures and some
exceptional examples, but for most boats that is far too much heel for
best performance. The fact that you *think* you are proving something is
really kind of amusing.

Fresh Breezes- Doug King

IACC Boat speed at 30 degrees heel?
 

DSK wrote:

Nav wrote:

Wrong again. Look at the references.


OK, I bow to your greater experience with googling and bookshelf
sailing. Heel your boat to 30 degrees all you want, it's fun. Who am I
to try and convince you to look around in the real world?


Don't you get it Doug? 30 degrees heel is quite normal (and often very
fast upwind) for most big keel boats! For proof look at the refs I've cited!
They also contain real tests of real boats by experts. The funny thing
is that the boats really are faster at the sort of angle I've quoted
than at 12 degrees. I guess you'd say they must all be wrong too? What
would Herreschof say?

Cheers.

IACC Boat speed at 30 degrees heel?
 

Nav wrote:
Don't you get it Doug? 30 degrees heel is quite normal (and often very
fast upwind) for most big keel boats! For proof look at the refs I've
cited!

You hve cited some pics and references to some very UNusual,
far-outside-the-normal specialized boats. But you don't even realize
that, do you?

They also contain real tests of real boats by experts. The funny thing
is that the boats really are faster at the sort of angle I've quoted
than at 12 degrees. I guess you'd say they must all be wrong too? What
would Herreschof say?

Any of the Herreshoffs would probably say, "Don't argue with an idiot,
Doug, people might not be able to tell the difference. And besides, let
Navvie heel his boat 'way 'way over if it makes him feel all manly."

The only reason I have kept in this discussion is to counterbalance your
whacky suggestions that might be taken seriously by novice sailors. But
I think the time for that is passed.

Fresh Breezes- Doug King

IACC Boat speed at 30 degrees heel?
 

DSK wrote:



You are dead wrong on this one -admit it.


Nope, so far you have provided some interesting pictures and some
exceptional examples, but for most boats that is far too much heel for
best performance. The fact that you *think* you are proving something is
really kind of amusing.


So according to you the books I quoted on naval architecture are wrong?
Oh boy.

Cheers

IACC Boat speed at 30 degrees heel?
 

I wonder why Hood talk about sail design for Italy on the basis of an
IACC 30 degree heel? They must be wron according to Doug too! But,
didn't Prada win the LV?

http://www.hoodsailmakers.it/eng/reg..._aero/aero.htm


You are sooooooooo busted.

Cheers

IACC Boat speed at 30 degrees heel?
 

DSK wrote:



They also contain real tests of real boats by experts. The funny thing
is that the boats really are faster at the sort of angle I've quoted
than at 12 degrees. I guess you'd say they must all be wrong too? What
would Herreschof say?


Any of the Herreshoffs would probably say, "Don't argue with an idiot,
Doug, people might not be able to tell the difference. And besides, let
Navvie heel his boat 'way 'way over if it makes him feel all manly."

Good lord. Have you seen any pictures of Hereshoff racing? When he's
powered up he's got lots more than 12 degrees heel! No, wait, he can't
know anything 'cos Doug says 12 degrees is optimum. Hahahahhahaha What
did I post about the Gimcrack? hahhahahahaha Oh boy you are a class unto
yourself!


The only reason I have kept in this discussion is to counterbalance your
whacky suggestions that might be taken seriously by novice sailors. But
I think the time for that is passed.


Well as long as you keep giving your advice to American sailors, the
world won't have to worry about the USA winning any keelboat
competitions. 12 degrees heel is fastest for keelboats? I guess that's
why designers use 30 degrees?

Bwhahahahhahahaha

Cheers

IACC Boat speed at 30 degrees heel?
 

"Nav" wrote in message
...


DSK wrote:

Anyway, long narrow boats like the IACC class and the old 12s too
tend to sail at higher angles of heel than more normally proportioned
boats. I still think 30 degrees is a bit of an overstatement.




Nav wrote:
Wot only a 'bit' now is it? Just yesterday you rubbished it! Doug,
lots of boats are only fully powered up at 30 (or more) degrees heel.


OK, I am still not sure what you mean by "powered up." It sounds to me
like you are relishing the feeling of heeling too much. It's fun, but
it's really not fast.

.... Of course as a dingly sailor you wouldn't know that but it's
really true.


Spoken like one whose experience in racing class dinghies is limited to
embarassing capsizes within 100 yards of the club dock.


Let me paint a typical picture for you: At that 30 degrees heel the
boat is alive and really punching through waves to windward.


At 30 degrees heel, the boat is heeling too much. It is "punching"
through waves because the hull presenting a set of awkward angles. Other
boats have depowered a little and are going faster.

Have you done any big boat sailing or been in a race in windy
conditions? Why not read the book whose URL I posted and then come back
on it. Better yet go back to the classic literature and look at the
tests of the Gimcrack. She was fastest at 30 degrees and was no faster
at 35 degrees. That's still a correct rule of thumb for most fast
cruiser racers today.

Perhaps Donal would like to post the figs. for his boat -if he's got them?

I'm waaay out of my depth here. However, Doug's words are making more sense
to me.


I've done the Round the Island (~65 miles) several times, with an
experienced, and competent helmsman. As you can imagine, my confidence has
increased each year. The first year, I was as culeless as Bobsprit.


My helmsman was a great sailor, but he had two faults. He always had
everything (halyards, sheets, etc) too tight, -- and he always sailed as if
he was in match racing.


Our third race was the best. I wasn't confident enough to take the tiller,
but I *was* confident enough to do the start, and control the sail plan
during the race.

The following year, I also did the helm - and we did crap. So, I'm an
average tactician, and a lousy helm. I *do* feel that my boat will perform
much better if she is reefed a bit earlier.


PS. I'm incredibly lucky with my crew. One of them has crossed the
Atlantic 3 times, one has done the Fastnet twice. I'm lucky that we get on
so well together.


Regards


Donal
--

IACC Boat speed at 30 degrees heel?
 

Nav wrote:
Good lord. Have you seen any pictures of Hereshoff racing?


Which Herreshoff? One of the designers or one of the designs? Do you
even know how many designers are/were in the Herreshoff family?

... When he's
powered up he's got lots more than 12 degrees heel! No, wait, he can't
know anything 'cos Doug says 12 degrees is optimum.

You don't know what I said, do you? Do you bother to read any posts but
your own?

DSK

IACC Boat speed at 30 degrees heel?
 

DSK wrote:

Nav wrote:

Good lord. Have you seen any pictures of Hereshoff racing?



Which Herreshoff? One of the designers or one of the designs? Do you
even know how many designers are/were in the Herreshoff family?

Nat.


... When he's powered up he's got lots more than 12 degrees heel! No,
wait, he can't know anything 'cos Doug says 12 degrees is optimum.


You don't know what I said, do you? Do you bother to read any posts but
your own?


Whoa! Talk about the pot calling the kettle... Do _you_ even read what
_you_ post. OK here's what you posted: "Most boats like about 12 degrees
of heel."

Since you were rubbishing the 30 degree heel for IACC boats, the
GIMCRACK data I posted and the common design criteria of 30 degrees heel
it is clear isn't it?

Cheers


DSK

IACC Boat speed at 30 degrees heel?
 

Nav,

Really!! You're not being fair calling those "Solo around the world"
boats mono's. Their beams are so wide and their draft so shallow that
they are Cats built in one piece and designed to sail with more than
half the hull flying.

They were just about as bad as the Kiwi POS used for the cup defense.

Their failure rate in that last so called race wound up being for
survival and not for speed!

Ole Thom

IACC Boat speed at 30 degrees heel?
 

Which Herreshoff?

Nav wrote:
Nat.

Well, that's one question answered. Are you going to answer the second (
I know you'd prefer to ignore the third)?

Read and learn
http://www.employees.org/~b299/herreshoff.html

One of the designers or one of the designs?

I'd assume you mean one of Nat Herreshoff's designs, since his renown
was not as a skipper.

http://www.herreshoff.org/
Unfortunately not too many photos available here, but the one on the
cover page is Reliance (1903) heeling what appears to be about 20
degrees (Oz will be pleased to note that her rail is just clear of the
water).

.....OK here's what you posted: "Most boats like about 12 degrees
of heel."

And so, you take that one remark out of context and based on that alone,
post 100 attacks on me?

When are you going to post the results of your emails which were going
to *prove* that I'm a liar?

DSK

Herreshoff Pic... & more heel
 

http://www.herreshoff.org/frames/mmphotojboat6big.htm

This is the America's Cup winner of 1930, an N.G. Herreshoff design and the
last AmCup racer with a centerboard. The wind looks fairly light (although
remember that this boat is 120+' LOA, which distorts the scale) and the boat
is heeling 12 ~ 15 degrees... but look at the wake. Obviously the boat is
moving well. But is it "powered up"?

BTW the rest of the series os pretty nice too.

I suspect that Navvie (and a lot of others) consistently overestimate heel
angle. When you're on the boat, the constant motion makes it seem like the
boat is heeling a lot more than it really is. I've had people tell me we
were heeling 45 degrees when in fact it was only 20 on the fun-meter. When
looking at pics, the angle of the leach always exaggerates the heel too.

Fresh Breezes- Doug King

Herreshoff Pic... & more heel
 

Nice photo's. I looked at all of them
starting here.

http://www.herreshoff.org/frames/mmphotoframe.htm


DSK wrote

http://www.herreshoff.org/frames/mmphotojboat6big.htm

This is the America's Cup winner of 1930, an N.G. Herreshoff design and the
last AmCup racer with a centerboard. The wind looks fairly light (although
remember that this boat is 120+' LOA, which distorts the scale) and the boat
is heeling 12 ~ 15 degrees... but look at the wake. Obviously the boat is
moving well. But is it "powered up"?

BTW the rest of the series os pretty nice too.

I suspect that Navvie (and a lot of others) consistently overestimate heel
angle. When you're on the boat, the constant motion makes it seem like the
boat is heeling a lot more than it really is. I've had people tell me we
were heeling 45 degrees when in fact it was only 20 on the fun-meter. When
looking at pics, the angle of the leach always exaggerates the heel too.

Fresh Breezes- Doug King

IACC Boat speed at 30 degrees heel?
 

Nav,

If you go back and read the opening paragraph on Hood's design goal of
sails, you have "BUSTED YOURSELF!"

They state the goal of design is to; "mininmize drag and heel"

My friend, I do believe you are beating yourself to death trying to get
at Doug. Give it up.

OT

Herreshoff Pic... & more heel
 

DSK wrote:
http://www.herreshoff.org/frames/mmphotojboat6big.htm

This is the America's Cup winner of 1930, an N.G. Herreshoff design and the
last AmCup racer with a centerboard. The wind looks fairly light (although
remember that this boat is 120+' LOA, which distorts the scale) and the boat
is heeling 12 ~ 15 degrees... but look at the wake. Obviously the boat is
moving well. But is it "powered up"?

No it isn't. She's not near her hull speed (look at the stern) and the
wind is light. I'll be she'd be closer to hull speed when heeld to 25-30.

Cheers

Herreshoff Pic... & more heel
 

http://www.herreshoff.org/frames/mmphotojboat6big.htm
.... But is it "powered up"?


Nav wrote:
No it isn't. She's not near her hull speed (look at the stern) and the
wind is light. I'll be she'd be closer to hull speed when heeld to 25-30.

And I bet she's going appreciably faster, and a much higher percentage
of her hull speed, than you think.

As for light wind, this is a boat of approx 130' LOA. What looks like
ripples on the water around her is a substantial chop.

Secondly, when I look at the stern and just aft of the stern, I see a
substantial wave train. With a 90 foot waterline, she could be moving at
10+ knots making such waves.

BTW this boat is one of those type specifically designed to increase the
waterline when heeled. But not as extreme a type as this one

http://boatdesign.net/gallery/showph...cat/all/page/1

http://www.boatdesign.net/gallery/sh.../cat/501/page/

BTW this second pic has the grand daddy heavyweight champ of all stern
waves... boat is heeled a good bit... about time to take in that topsail
I'd think ;)

Fresh Breezes- Doug King

Herreshoff Pic... & more heel
 

DSK wrote:



http://www.boatdesign.net/gallery/sh.../cat/501/page/


BTW this second pic has the grand daddy heavyweight champ of all stern
waves... boat is heeled a good bit... about time to take in that topsail
I'd think ;)


What would you estimate the angle of heel to be?

Cheers

Herreshoff Pic... & more heel
 

Now this _is_ too much

http://www.boatdesign.net/gallery/sh.../cat/501/page/

Cheers

DSK wrote:

http://www.herreshoff.org/frames/mmphotojboat6big.htm
.... But is it "powered up"?



Nav wrote:
No it isn't. She's not near her hull speed (look at the stern) and the
wind is light. I'll be she'd be closer to hull speed when heeld to 25-30.


And I bet she's going appreciably faster, and a much higher percentage
of her hull speed, than you think.

As for light wind, this is a boat of approx 130' LOA. What looks like
ripples on the water around her is a substantial chop.

Secondly, when I look at the stern and just aft of the stern, I see a
substantial wave train. With a 90 foot waterline, she could be moving at
10+ knots making such waves.

BTW this boat is one of those type specifically designed to increase the
waterline when heeled. But not as extreme a type as this one

Now this _is_ too much

http://www.boatdesign.net/gallery/sh.../cat/501/page/

Cheers

Herreshoff Pic... & more heel
 

Nav wrote:
Now this _is_ too much

http://www.boatdesign.net/gallery/sh.../cat/501/page/

How about this

http://www.boatdesign.net/gallery/sh...php/photo/334/

What do you estimate the heel angle of these two to be? Hint- is is
pretty close to the range you were claiming is "powered up" earlier.

BTW you never did clarify what you meant by 'powered up' with regard to
VMG or speed relative to true wind velocity or what.

DSK

Herreshoff Pic... & more heel
 

DSK wrote:

Nav wrote:

Now this _is_ too much

http://www.boatdesign.net/gallery/sh.../cat/501/page/



How about this

http://www.boatdesign.net/gallery/sh...php/photo/334/

What do you estimate the heel angle of these two to be? Hint- is is
pretty close to the range you were claiming is "powered up" earlier.


You really think that boat (?668) is beating to windward? Is 45 close to
30 when discussing trim and heeling?


Cheers

IACC Boat speed at 30 degrees heel?
 

he he, I still chuckle at the picture of them bailing out the boat with
their cedar bucket.
;)

Scotty


"Thom Stewart" wrote in message
...
Nav,

Really!! You're not being fair calling those "Solo around the world"
boats mono's. Their beams are so wide and their draft so shallow that
they are Cats built in one piece and designed to sail with more than
half the hull flying.

They were just about as bad as the Kiwi POS used for the cup defense.

Their failure rate in that last so called race wound up being for
survival and not for speed!

Ole Thom

IACC Boat speed at 30 degrees heel?
 

It was very sad indeed. To have banked their defense so heavily on
lighter winds was not a good call.

Cheers

Scott Vernon wrote:

he he, I still chuckle at the picture of them bailing out the boat with
their cedar bucket.
;)

Scotty


"Thom Stewart" wrote in message
...

Nav,

Really!! You're not being fair calling those "Solo around the world"
boats mono's. Their beams are so wide and their draft so shallow that
they are Cats built in one piece and designed to sail with more than
half the hull flying.

They were just about as bad as the Kiwi POS used for the cup defense.

Their failure rate in that last so called race wound up being for
survival and not for speed!

Ole Thom

IACC Boat speed at 30 degrees heel?
 

sad? I thought it was funny.

SV

"Nav" wrote in message
...
It was very sad indeed. To have banked their defense so heavily on
lighter winds was not a good call.

Cheers

Scott Vernon wrote:

he he, I still chuckle at the picture of them bailing out the boat with
their cedar bucket.
;)

Scotty


"Thom Stewart" wrote in message
...

Nav,

Really!! You're not being fair calling those "Solo around the world"
boats mono's. Their beams are so wide and their draft so shallow that
they are Cats built in one piece and designed to sail with more than
half the hull flying.

They were just about as bad as the Kiwi POS used for the cup defense.

Their failure rate in that last so called race wound up being for
survival and not for speed!

Ole Thom

IACC Boat speed at 30 degrees heel?
 

I see. I expected more from you.

Cheers

Scott Vernon wrote:

sad? I thought it was funny.

SV

"Nav" wrote in message
...

It was very sad indeed. To have banked their defense so heavily on
lighter winds was not a good call.

Cheers

Scott Vernon wrote:


he he, I still chuckle at the picture of them bailing out the boat with
their cedar bucket.
;)

Scotty


"Thom Stewart" wrote in message
...


Nav,

Really!! You're not being fair calling those "Solo around the world"
boats mono's. Their beams are so wide and their draft so shallow that
they are Cats built in one piece and designed to sail with more than
half the hull flying.

They were just about as bad as the Kiwi POS used for the cup defense.

Their failure rate in that last so called race wound up being for
survival and not for speed!

Ole Thom

IACC Boat speed at 30 degrees heel?
 

You didn't see the humour in a multi million dollar boat, with a multi
million dollar crew backed by a multi million dollar syndicate being bailed
with a plastic bucket?

SV


"Nav" wrote in message
...
I see. I expected more from you.

Cheers

Scott Vernon wrote:

sad? I thought it was funny.

SV

"Nav" wrote in message
...

It was very sad indeed. To have banked their defense so heavily on
lighter winds was not a good call.

Cheers

Scott Vernon wrote:


he he, I still chuckle at the picture of them bailing out the boat with
their cedar bucket.
;)

Scotty


"Thom Stewart" wrote in message
...


Nav,

Really!! You're not being fair calling those "Solo around the world"
boats mono's. Their beams are so wide and their draft so shallow that
they are Cats built in one piece and designed to sail with more than
half the hull flying.

They were just about as bad as the Kiwi POS used for the cup defense.

Their failure rate in that last so called race wound up being for
survival and not for speed!

Ole Thom

IACC Boat speed at 30 degrees heel?
 

What did you expect them to do, switch on a pump or something?

Cheers

Scott Vernon wrote:

You didn't see the humour in a multi million dollar boat, with a multi
million dollar crew backed by a multi million dollar syndicate being bailed
with a plastic bucket?

SV


"Nav" wrote in message
...

I see. I expected more from you.

Cheers

Scott Vernon wrote:


sad? I thought it was funny.

SV

"Nav" wrote in message
...


It was very sad indeed. To have banked their defense so heavily on
lighter winds was not a good call.

Cheers

Scott Vernon wrote:



he he, I still chuckle at the picture of them bailing out the boat with
their cedar bucket.
;)

Scotty


"Thom Stewart" wrote in message
...



Nav,

Really!! You're not being fair calling those "Solo around the world"
boats mono's. Their beams are so wide and their draft so shallow that
they are Cats built in one piece and designed to sail with more than
half the hull flying.

They were just about as bad as the Kiwi POS used for the cup defense.

Their failure rate in that last so called race wound up being for
survival and not for speed!

Ole Thom

IACC Boat speed at 30 degrees heel?
 

design a decent boat.

"Nav" wrote ...
What did you expect them to do?

IACC Boat speed at 30 degrees heel?
 

Nav
scribbled thusly:
It was very sad indeed. To have banked their defense so heavily on
lighter winds was not a good call.



Oz wrote:
Actually I think it was a case of lack of testing.

Well, Team NZ said all along in the build-up to the match, that they had
invested more heavily in design and did not have the resources to spend
on on-water tuning. If they had increased their actual sailing time by
maybe 50% they would have had much more chance. It was a question of
having priorities in the wrong place.

BTW I wonder what figure is, dollars per hour, for sailing one of these
boats... not including initial design & building costs. I'm sure that in
heavier winds it gets more expensive, too.

FWIW I don't think Jochen Schumann got nearly enough credit for managing
Alinghi to their win. He is one of the greatest sailor of this
generation IMHO

Fresh Breezes- Doug King

Herreshoff Pic... & more heel
 

Nav wrote:
You really think that boat (?668) is beating to windward?

It looks like they are attempting to. Do you think they are heeled too
much for best VMG?


... Is 45 close to
30 when discussing trim and heeling?

IIRC at one point you said "30 to 40 degrees of heel" in relation to
being 'powered up' which you never could define.

In any event, 45 is a lot closer to 30 than it is to 20

DSK

Herreshoff Pic... & more heel
 

DSK wrote:

Nav wrote:

You really think that boat (?668) is beating to windward?


It looks like they are attempting to. Do you think they are heeled too
much for best VMG?



Please tell us about your sailing ideas where a spinnaker is carried as
a beating sail.


... Is 45 close to 30 when discussing trim and heeling?


IIRC at one point you said "30 to 40 degrees of heel" in relation to
being 'powered up' which you never could define.

No, I never said 30 to 40 degrees. It's your exaggeration coming in
again. I said IACC are powered up at 30.



In any event, 45 is a lot closer to 30 than it is to 20


Now you've gone from 30 to 40 to 45! Anyway you are wrong again. Wind
pressure (and therefore potential power extractionon) on the sail must
proprotional to the sine of the heel while leeway will rise roughly with
the cosine. OK?

The consequence of this is that keel boat speed will rise as wind
pressure on the sail rises but VMG will not continue to rise so fast and
will eventually fall due to leeway taking away from the windward
progress. Due to the shape of sines and cosines (I hope you know this)
the sine initailly rises more quickly than the cosine falls. Thus VMG
goes up monotonically with heel until sine and cosine functions have
opposite effects on VMG. At this point, the boat is sailing fast and
fastest to windward and to use my parlance it is fully powered up. A bit
more heel may well give more speed but VMG falls -and falls
progressively faster with more heel. That's why we have accurate VMG
instruments on board (but dinghy sailors have to guess their VMG which
is hard). From that design angle, VMG falls more and more quickly. The
designer picks a point to work on (typically 30 degrees as I said) to
decide freeboard. Thus at 45 dgrees heel VMG is probably well down and
the rails are going under (drag). This is not the same as when going
from 20 to 30 degrees heel. At ~30 the VMG for an IACC is highest, as I
said and this was also true for the classic 6m type Gimcrack whose very
accurate figures I gave you. Perhaps you should try to read Dr. Curry's
book 'Yacht Racing' (if you can find a copy) for qualitative discourse
on the effects of heel on real yachts? Now, It is possible to shape a
hull to have even more power at 30 degrees heel but the reason why this
is not done is that 30 degrees is also considered to be a human limit
for working comfort. If you had sailed offshore you would know that
heeling beyond 30 for any period is very hard on the body. I suggest the
current Beneteaus were designed to have lower human design angles for
the market they are aimed at -the charter/fun boat market. Mure purist
cruiser/racers (like Ella) take higher heel to reach peak VMG and also
carry full sail to higher windspeeds. Don't forget Ella was designed for
the roaring 40's -not the Med.

OK?

Cheers

IACC Boat speed at 30 degrees heel?
 

DSK wrote:



FWIW I don't think Jochen Schumann got nearly enough credit for managing
Alinghi to their win. He is one of the greatest sailor of this
generation IMHO


Can you explain why he wasn't helming -if he's that good?

Cheers

Herreshoff Pic... & more heel
 

Nav wrote:

Please tell us about your sailing ideas where a spinnaker is carried as
a beating sail.

I thought you were talking about the Valsheda pic.


In any event, 45 is a lot closer to 30 than it is to 20


..... Wind
pressure (and therefore potential power extractionon) on the sail must
proprotional to the sine of the heel while leeway will rise roughly with
the cosine. OK?

It seems to me that before you start to yabble about trig & calculus, you
should learn some basic math. 45 is definitely a lot closer to 30 than it is
to 20. Look it up.

In any event, your posts have become a morass of insults and double talk.
There is no basic fact so obvious that you won't deny it to try and "prove"
that I am wrong. It's predictable and boring. If you are going to be a
caricature, you should at least try & be funny!

DSK

Herreshoff Pic... & more heel
 

DSK wrote:

Nav wrote:


Please tell us about your sailing ideas where a spinnaker is carried as
a beating sail.


I thought you were talking about the Valsheda pic.


Well I even gave the sail number to make sure we were talking about the
same pic! Was that too hard for you to read?

In any event, 45 is a lot closer to 30 than it is to 20


..... Wind
pressure (and therefore potential power extractionon) on the sail must
proprotional to the sine of the heel while leeway will rise roughly with
the cosine. OK?


It seems to me that before you start to yabble about trig & calculus, you
should learn some basic math. 45 is definitely a lot closer to 30 than it is
to 20. Look it up.

Oh, now I can see the level of your maths ability. So you are not
interested in the behaviour of the boat but just want to say that 15 is
less than 25? If you had told me I was going to be talking to someone
with the maths ability of an 8 year old I would not have bothered
posting a detailed discussion on the basis of the relationship between
heel and VMG. If this is the case, then I apologise for posting
something so far above your education level that you think it double talk.


In any event, your posts have become a morass of insults and double talk.

Maths is is not double talk. It's precise and accurate and as for
insults, it's you that always starts it e.g. your last post.

There is no basic fact so obvious that you won't deny it to try and "prove"
that I am wrong. It's predictable and boring. If you are going to be a
caricature, you should at least try & be funny!


I though you claimed to be interesting in learning about sailing. I can
only surmise that this a lie because when I try to clarify your
misconceptions you become insulting and simply ignore what is said. Even
worse you then change what was said to suit your peculiar form of troll.
Why not try to engange your brain and think about what I wrote? I'd
enhjoy an intelligent conversation with you. Here, I'll post it again.
Read it. Is it wrong? Come to that, why did you bring up the number 45
anyway -was it only to make the irrelvant point that 45-30 30-20?
What could be the point of that in the context of discussing keel boat
_performance_?

Cheers

Herreshoff Pic... & more heel
 

Nav wrote:
Maths is is not double talk.

Your attempts are.


....when I try to clarify your
misconceptions

LOL

That's better Navvie.

DSK

Herreshoff Pic... & more heel
 

DSK wrote:
Nav wrote:

Maths is is not double talk.


Your attempts are.


....when I try to clarify your misconceptions


LOL

That's better Navvie.


Do you still think boats use spinnakers for beating to windward?

Cheers