Hi Sam

Sorry about the really dum questions but they eliminate some obvious things.
So we can look into the other possibilities.

-----Original Message-----
From: corsair_136 [mailto:samc@...]
Sent: Wednesday, 28 January 2004 3:22 PM
To: CorsairAustralia@...
Subject: [CorsairAustralia] Re: pointing up wind


Thanks for your great reply Ken,

> Are you new to sailing?
I've never owned a boat, until now, but have spent many summers on
Sabots, windsurfers and the corsair I now own... so I am familiar
with some of the concepts, but very little of the lingo.

[Ken Webster] Good, you know what you are doing.

> Was there a strong current and little wind?
there was a fairly strong current... the water tends to race out just
off Sorrento in Port Phillip Bay.

[Ken Webster] The boat may have been performing OK but this can only be measured
relative
to the water. If the water is moving as well, the boat goes with it. If you
were fighting a strong
current, that explains your lack of progress. Current tends to be slower on the
inside of bends
and in shallows so you can use these areas to assist your progress. Shallows
are a last resort
though because apart from the annoying tendency to ground the centreboard, they
increase
drag on the hull. You can also use slack water behind headlands and points to
assist progress
against current.

> Were there large wind shifts?
I guess there were.

[Ken Webster] You don't sound sure, but as I said in the previous post, wind
shifts can make a
big difference. Any shift that is disadvantageous on one tack is an advantage
on the other. It's
up to you, which it will be, That could be a factor also.

> Does the main and jib both luff at the same instant?
no, the jib was doing most of the luffing

[Ken Webster] That suggests, the jib is not pulled in enough. You will probably
need to adjust
the jib sheet block more inboard until both main and jib work together, luff at
the same time.
This is really important to get the boat to point up into wind properly. The jib
accelerates the
wind through the slot between main and jib. That increases the efficiency of
the main.
You want to get the slot as narrow as possible without back winding on the main.
This is often
done by putting several turns of chord between the sheet block and whatever it
is shackled to,
then adjust the length of the chord until you get it right.

> Does the boat swing upwind or down wind or load the helm
> in gusts?
upwind

[Ken Webster]
That is weather helm, most boats are initially set up that way for safety, as a
gust hits, the boat
luffs up and spills wind. However this causes induced drag on the rudder so is
no good for racing.
It is your call if you want to reduce it or not. Raking the mast forward to
increase sail area forward
of the centre board will reduce weather helm. This can be done by lengthening
the side stays and
retightening the fore stay. Some boats have adjustable plates on the stays for
this. You can do
some tests in medium wind conditions by replacing the side stay shackles with
loops of
VERY STRONG chord. That way you can adjust mast rake to get an idea of the
final adjustment
needed. Then use adjustable plates or add extra shackles for the permanent rig.

Note: Wether helm when well healed over is normal, we are only concerned here
if this tendency
persists at normal trim.


Regards,
Ken



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