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FamilySailor
 
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Default Mac 26x for sailing speed

Maybe he doesn't know what apparent wind is. He could have been sailing
DDW,
thinking the wind was less than one knot, when it was actually 6 knots.

BB

We were beating into the wind. and the water was like glass. And you should
know that you could have a wind speed of 0.1 knots and it will move the boat
if there is no current opposing it. The speed of the boat is relative to the
speed of the wind. I guess most people would crank up the screaming
outboard, but we were there for a week of sailing and in no hurry. We had
all day to go from Echo bay to Center point. Most of the Macs cranked up
their engines and beat us there, but we sailed all the way. And sailing in
while others gave up, just makes you feel good about whole day. In the days
of old all they had were their sails. As far as the captain making too many
tacks, well, I gave my advice once and did not worry about it. I was not the
skipper and it did not really matter. I was there to get away and sail. The
Mac that passed us did point that out to the skipper later that evening
though.


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Jeff Morris
 
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Default Mac 26x for sailing speed


"FamilySailor" wrote in message ...
Maybe he doesn't know what apparent wind is. He could have been sailing

DDW,
thinking the wind was less than one knot, when it was actually 6 knots.

BB

We were beating into the wind. and the water was like glass. And you should
know that you could have a wind speed of 0.1 knots and it will move the boat
if there is no current opposing it.


No, I'll go out on a limb and claim that in a practical situation, 0.1 knots of
wind will not generate enough force to overcome the hull friction. At one knot,
the pressure on the sail is roughly a pound or two - but the force is
proportional to the square of the wind strength, so at 0.1 knots of wind we're
down to several grams of force.

Even if you could go at the wind speed (highly unlikely), that's only 600 feet
in an hour.

The speed of the boat is relative to the
speed of the wind. I guess most people would crank up the screaming
outboard, but we were there for a week of sailing and in no hurry.


I remember a regatta that was postponed due to lack of wind - we held "kinetic
races" using all the techniques strictly forbidden by the rules. Several
skippers were doing a few knots just by roll tacking viorously.

We had
all day to go from Echo bay to Center point. Most of the Macs cranked up
their engines and beat us there, but we sailed all the way. And sailing in
while others gave up, just makes you feel good about whole day. In the days
of old all they had were their sails.


And their oars.

As far as the captain making too many
tacks, well, I gave my advice once and did not worry about it. I was not the
skipper and it did not really matter. I was there to get away and sail. The
Mac that passed us did point that out to the skipper later that evening
though.




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SAIL LOCO
 
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Default Mac 26x for sailing speed

And you should
know that you could have a wind speed of 0.1 knots and it will move the boat
if there is no current opposing it.

Excuse me but if you had winds of .1 kts or anything less than 1 kt your sails
were probably hanging limp.
S/V Express 30 "Ringmaster"
"Trains are a winter sport"
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FamilySailor
 
Posts: n/a
Default Mac 26x for sailing speed

They were hanging limp alright. For quite a while. We would get an
immeasurable puff every now and then. I'm not too worried about convincing
you. I was there. You believing me or not changes nothing. What is, is what
is and what we did is what we did...
;-)
Winds were below 1 knot and we were making headway. I used the 0.1 knot just
as a number to post for my example. Oh, and the friction of the water
against the hull in nonexistant (zero), until the hull starts to move, then
you have friction. So as we moved along slowly the friction slowed us as it
always does with all boats. But, unless the water is moving against the
forward motion of the hull, or is frozen solid, it will not hold your boat
stationary. That was a good one! Fluid motionless water holding a sailboat
stationary.......


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Scout
 
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Default Mac 26x for sailing speed

maybe you were in hard water ; )
Scout

"FamilySailor" wrote in message
...
They were hanging limp alright. For quite a while. We would get an
immeasurable puff every now and then. I'm not too worried about convincing
you. I was there. You believing me or not changes nothing. What is, is

what
is and what we did is what we did...
;-)
Winds were below 1 knot and we were making headway. I used the 0.1 knot

just
as a number to post for my example. Oh, and the friction of the water
against the hull in nonexistant (zero), until the hull starts to move,

then
you have friction. So as we moved along slowly the friction slowed us as

it
always does with all boats. But, unless the water is moving against the
forward motion of the hull, or is frozen solid, it will not hold your boat
stationary. That was a good one! Fluid motionless water holding a sailboat
stationary.......






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Jeff Morris
 
Posts: n/a
Default Mac 26x for sailing speed

"FamilySailor" wrote in message ...
They were hanging limp alright. For quite a while. We would get an
immeasurable puff every now and then. I'm not too worried about convincing
you. I was there. You believing me or not changes nothing. What is, is what
is and what we did is what we did...
;-)


I certainly don't doubt that you were ... I've been there myself.


Winds were below 1 knot and we were making headway.


I'm curious, how do you measure that? The various annemometers I have stop
turning at speeds that low. Even smoke rising from a cigarette is close to
vertical when you go much below a knot.

I used the 0.1 knot just
as a number to post for my example. Oh, and the friction of the water
against the hull in nonexistant (zero), until the hull starts to move, then
you have friction.
So as we moved along slowly the friction slowed us as it
always does with all boats. But, unless the water is moving against the
forward motion of the hull, or is frozen solid, it will not hold your boat
stationary. That was a good one! Fluid motionless water holding a sailboat
stationary.......



I'm sure there is some component of friction that is not dependent on speed,
though it may be quite small. Its a little hard to find data for this, since it
has no commerical value.

However, I did say "in a practical situation," so it becomes fairly hard to show
that there's any motion on a 3 ton boat when there's only a few grams of force
(unless its in space). There are other problems - such as holding anything
like a proper sail shape, and leeway can be atrocious at very low speed. And
the rudder is effectively useless. Actually, if the wind was truely that low,
any rocking of the boat, or rudder motion would generate greater forces than the
wind.


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FamilySailor
 
Posts: n/a
Default Mac 26x for sailing speed

Winds were below 1 knot and we were making headway.

I'm curious, how do you measure that? The various annemometers I have

stop
turning at speeds that low. Even smoke rising from a cigarette is close

to
vertical when you go much below a knot.

Well, one could pee in the water and then watch the bubbles. I just watched
the water moving past the rudder and the sediment in the water moving from
the bow to the stern. How would you detect movement? We also had a GPS that
was leaving tracks. Another thing, we ended up at a different location, so I
believe that would indicate some movement was involved. You act like 1 knot
is almost stationary and smoke would go straight up, but think about it.
That is moving at a rate 5,280 in just one hour, or 1.47' per second. It is
easy to detect movement and using a GPS to measure distance and the amount
of time required to cover that distance. Anyway, I did not do all that, I
just made an observation and said the wind speed is about 1 knot or less, no
measuring device needed. Give me a break.


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SAIL LOCO
 
Posts: n/a
Default Mac 26x for sailing speed

We also had a GPS that was leaving tracks.

That only means you were moving over the bottom. Not thru the water. You were
probably drifting with the current.
S/V Express 30 "Ringmaster"
"Trains are a winter sport"
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Jeff Morris
 
Posts: n/a
Default Mac 26x for sailing speed

"FamilySailor" wrote in message ...
Winds were below 1 knot and we were making headway.


I'm curious, how do you measure that? The various annemometers I have

stop
turning at speeds that low. Even smoke rising from a cigarette is close

to
vertical when you go much below a knot.

Well, one could pee in the water and then watch the bubbles. I just watched
the water moving past the rudder and the sediment in the water moving from
the bow to the stern. How would you detect movement? We also had a GPS that
was leaving tracks. Another thing, we ended up at a different location, so I
believe that would indicate some movement was involved.


I wasn't questioning whether you were moving, though I doubt very much you were
going at wind speed in a drifter. In fact, the only reason I commented at all
is that I've never heard anyone talk about a windspeed of a tenth of a knot, and
I thought that was a curious concept to explore.

You act like 1 knot
is almost stationary and smoke would go straight up, but think about it.
That is moving at a rate 5,280 in just one hour, or 1.47' per second.


I did the same calculation (though I used the correct value for one knot, which
is 1.69 feet/second) before posting, which is why I said "much less than a
knot." The smoke from a cigarette rises pretty quickly. so you actually have
less than a second's worth to observe. In reality, in very light air like this
the wind can be virtually zero in the cockpit, but a knot or two, or more,
aloft.

It is
easy to detect movement and using a GPS to measure distance and the amount
of time required to cover that distance. Anyway, I did not do all that, I
just made an observation and said the wind speed is about 1 knot or less, no
measuring device needed. Give me a break.


Never! No nit can go unpicked!!! ;-}






 
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