On Mon, 20 Oct 2003 12:28:48 +0000, DSK wrote:

Lloyd Sumpter wrote:


OK...take your basic Merit/Olsen/Martin/Hotfoot/J and:

1. lose the $10K kevlar racing sails and put on dacron cruising sails

Why? If you've already got them, why not use them?


1. If you're buying new, you'd have to buy them, adding $10K to the
purchase price. Something cruisers don't do.
2. If they're used, the RACING concept would be to replace after a year to
two - again an expense most cruisers aren't will to accept.


2. put roller furling on the headsail and MAYBE a "cruising spinnaker"
(AKA "downwind floppy genoa")
3. Add 1500 lb or so of "cruising gear": 2 anchors, chain, etc. dishes,
water tank, holding tank, BBQ, crabtrap... (I had all this and more in my
Cal 25)
4. Add 6 mos accumulation of marine growth on the hull

Again, why? That's just plain neglectful and stupid. Especially on a small
boat that can be scrubbed with no great effort or time sunk.

How many times do you haul the boat?? If it's a racing boat, it often gets
hauled after every race, or at least many times in one year. Cruising
boats typically get hauled once a year. This is my point of "racing" vs
"cruising" mentality.



Now, sail it "cruising style": steer with your foot while you eat, tack
when you've finished lunch, leave the traveller centered, undercanvas so
you don't heel too much...

And you'll find these pocket rocketships don't go so fast. In fact, the
C25 may even beat it.

If the C25 was sailed under the same circumstances, not at all likely.


Hasn't been my experience. Many Martin 242's have been "converted" to
cruising boats, and they're not noticably faster than comparably-equipped
C25, C&C, US25, etc.


Why? The racers are designed to sail LIGHT and with
a lot of drive. For instance, they're not designed to sail downwind with a
genny. Many have very fine entries which work great when racing, but screw
up when there's 100lb of anchor gear in the bow.

Actually, the finer bow is likely to be slowed down less by weight forward.

I was referring to weight distribution. A lighter boat will suffer more
from "incorrect" weight placement than a heavier boat. Also, lack of
bouyance fwd WILL be more affected by weight fwd.

This kind of argument is common, but it's pure ignorance and wishful thinking.
FOr example, you know that Michael Jordan can jump higher than you, so that
suggests (by your logic) that you can therefore carry a heavier weight up a
hill.

Nope. My logic is more like "MJ can jump higher than an NFL lineman
because the lineman's way heavier. Make MJ the same weight as the lineman,
and I'll bet he couldn't jump as high as the lineman."

If a Catalina 25 is trialed against a Merit 25, with both of them light or
both of them loaded, the Merit is going to prove faster.


Totally "like for like"? Maybe. But noticably? In a race, 1/4 knot is VERY
significant, but cruising, 1/2 knot is nothing.



Now, I do notice that the C250 has one thing I HATE: "water ballast". Last
I checked, water is NOT heavier than water so IMHO does not constitute
"ballast" in a boat

Another example of ignorance.

Water is heavy. It doesn't have to be "heavier than water" to be ballast, it
just has to be below the boats center of gravity, or even below the boats
metacenter.

Tell me, is your boat's stability increased by filling a fuel tank down low in
the hull? Fuel is definitely lighter than water. How about a big cooler full
of ice & beer?


Compared to AIR, yes. Compared to lead, no. I'd show you the mathematics
if you feed me beer. In the meantime, try this experiment: fill a bottle
with water and see if it sinks.


Why not a full keel?

Too slow!

Lloyd Sumpter
"Far Cove" Catalina 36

Lloyd Sumpter wrote:


1. lose the $10K kevlar racing sails and put on dacron cruising sails

Why? If you've already got them, why not use them?


1. If you're buying new, you'd have to buy them, adding $10K to the
purchase price. Something cruisers don't do.

If you're going cruise, or race non-seriously, you can get 'normal' Dacron sails for
a Merit 25. The increased longevity of high tech sails usually makes them worth
having for somebody that sails a lot, though.... even cruising.....


2. If they're used, the RACING concept would be to replace after a year to
two - again an expense most cruisers aren't will to accept.

That doesn't make the Merit a slower boat than the Catalina 250... just that a Merit
with old sails is slower than a Merit 25 with new ones.



4. Add 6 mos accumulation of marine growth on the hull

Again, why? That's just plain neglectful and stupid. Especially on a small
boat that can be scrubbed with no great effort or time sunk.

How many times do you haul the boat?? If it's a racing boat, it often gets
hauled after every race, or at least many times in one year. Cruising
boats typically get hauled once a year. This is my point of "racing" vs
"cruising" mentality.

My point is that both are small boats. You can swim around them and scrub the bottom
two or three times a year and don't worry about hauling. Besides, if you're talking
about trailerables, then 'hauling' is a stupid thing to worry about.


And you'll find these pocket rocketships don't go so fast. In fact, the
C25 may even beat it.

If the C25 was sailed under the same circumstances, not at all likely.


Hasn't been my experience. Many Martin 242's have been "converted" to
cruising boats, and they're not noticably faster than comparably-equipped
C25, C&C, US25, etc.

In that case, I'd suspect that the boat has been more than just 'loaded to cruising
trim' and I'd also suspect that the skipper wasn't up to sailing fast anyway.




Why? The racers are designed to sail LIGHT and with
a lot of drive. For instance, they're not designed to sail downwind with a
genny. Many have very fine entries which work great when racing, but screw
up when there's 100lb of anchor gear in the bow.

Actually, the finer bow is likely to be slowed down less by weight forward.

I was referring to weight distribution. A lighter boat will suffer more
from "incorrect" weight placement than a heavier boat. Also, lack of
bouyance fwd WILL be more affected by weight fwd.

No it won't. The shape will still go through the water faster.

Basically, what you're trying to say is "This boat will beat that one under X
circumstances, so therefore the other boat will be faster under Y circumstances." As
though life were fair. It isn't. Just because Wayme Gretsky can beat you at hockey
doesn't mean you can automatically beat him at basketball.



.... My logic is more like "MJ can jump higher than an NFL lineman
because the lineman's way heavier. Make MJ the same weight as the lineman,
and I'll bet he couldn't jump as high as the lineman."

And you could still be wrong.



If a Catalina 25 is trialed against a Merit 25, with both of them light or
both of them loaded, the Merit is going to prove faster.


Totally "like for like"? Maybe. But noticably? In a race, 1/4 knot is VERY
significant, but cruising, 1/2 knot is nothing.

That depends on how far you're going. Each 1/2 knot is 4 miles further for every 8
hours sailing; which could mean getting to the same anchorage earlier or it could
mean getting to the next further anchorage. Besides, a boat with a more efficient
sail plan & underwater foils, such as the Merit or the Martin, is going to get to
windward at an increased margin over a 'cruising' boat.

Bottom line is, the Cat250 is roomier, but that doesn't automatically make it a
'better cruising' boat. And it darn sure doesn't make it faster with a load.


Tell me, is your boat's stability increased by filling a fuel tank down low in
the hull? Fuel is definitely lighter than water. How about a big cooler full
of ice & beer?


Compared to AIR, yes. Compared to lead, no. I'd show you the mathematics
if you feed me beer.

Math, huh? Do you do numbers any better than you do logic?

So... because lead ballast is better, as ballast, does that mean water cannot
function AT ALL as ballast?

No. Of course not.

So.... for a trailerable boat, where the weight of the ballast is a disadvantage at
specific and significant times, water is a pretty good choice for ballast.

Fresh Breezes- Doug King

On Mon, 20 Oct 2003 18:02:00 +0000, DSK wrote:

Lloyd Sumpter wrote:


Tell me, is your boat's stability increased by filling a fuel tank
down low in the hull? Fuel is definitely lighter than water. How
about a big cooler full of ice & beer?


Compared to AIR, yes. Compared to lead, no. I'd show you the
mathematics if you feed me beer.

Math, huh? Do you do numbers any better than you do logic?

So... because lead ballast is better, as ballast, does that mean water
cannot function AT ALL as ballast?

No. Of course not.



Yes, it does.

(actually, it's physics, not math, but you owe me a beer anyway)

Draw a diagram if you like. Now, the keel imparts a righting moment on the
boat because it exerts a downward force offset (in the x-dir) from the
center of rotation by the distance from the CofR (ie how deep the keel is)
and the angle of heel. Problem is, a water-filled keel does not sink and
therefore exerts NO downward force in water! (actually it does sink a bit
because the fibreglass the keel is made from sinks. You'd be better off
with a solid fibreglass keel...) Remember the water-filled bottle?

People think that because water is "heavy" in air means that it's also
"heavy" (ie exerts a significant downward force) in water. This is simply
not the case. Imagine this: get a boat with no keel and a mast. Put a rope
on the mast and pull on it, giving the boat heel. Now, put a boom out the
upward side with a bucket filled with water. As long as the bucket is in
air, it exerts a righting moment against the rope. But when it's in the
water, the only righting moment from the bucket is from the bucket itself
- the water exerts no righting moment whatsoever.

Now, having a water-filled keel that exerts virtually no downward force is
still preferable to an air-filled keel, which exerts an UPWARD force.
Also, water in the keel will help the boat's "stability" in that it
increases the overall mass (F=ma) so movement is dampened.

But "ballast"? No.

Lloyd Sumpter
"Far Cove" Catalina 36

I'm going to print this out and read it thoroughly, but, overall, I'm
going to disagree.
Filling a fuel tank or beer cooler, down low in the hull, will
DEFINITELY increase stability. It's a question of added weights to the hull.
Water Ballast, is a great way to add draft as well as stability, to a
hull (unless you leave the tank slack, in which case, the "free surface"
can outweigh the additional stability).

otn

Lloyd Sumpter wrote:

On Mon, 20 Oct 2003 18:02:00 +0000, DSK wrote:

Lloyd Sumpter wrote:



Tell me, is your boat's stability increased by filling a fuel tank
down low in the hull? Fuel is definitely lighter than water. How
about a big cooler full of ice & beer?



Compared to AIR, yes. Compared to lead, no. I'd show you the
mathematics if you feed me beer.

Math, huh? Do you do numbers any better than you do logic?

So... because lead ballast is better, as ballast, does that mean water
cannot function AT ALL as ballast?

No. Of course not.




Yes, it does.

(actually, it's physics, not math, but you owe me a beer anyway)

Draw a diagram if you like. Now, the keel imparts a righting moment on the
boat because it exerts a downward force offset (in the x-dir) from the
center of rotation by the distance from the CofR (ie how deep the keel is)
and the angle of heel. Problem is, a water-filled keel does not sink and
therefore exerts NO downward force in water! (actually it does sink a bit
because the fibreglass the keel is made from sinks. You'd be better off
with a solid fibreglass keel...) Remember the water-filled bottle?

People think that because water is "heavy" in air means that it's also
"heavy" (ie exerts a significant downward force) in water. This is simply
not the case. Imagine this: get a boat with no keel and a mast. Put a rope
on the mast and pull on it, giving the boat heel. Now, put a boom out the
upward side with a bucket filled with water. As long as the bucket is in
air, it exerts a righting moment against the rope. But when it's in the
water, the only righting moment from the bucket is from the bucket itself
- the water exerts no righting moment whatsoever.

Now, having a water-filled keel that exerts virtually no downward force is
still preferable to an air-filled keel, which exerts an UPWARD force.
Also, water in the keel will help the boat's "stability" in that it
increases the overall mass (F=ma) so movement is dampened.

But "ballast"? No.

Lloyd Sumpter
"Far Cove" Catalina 36

PS Add weight to the hull and you change stability. Add it high, you
lessen stability, add it low, and you increase stability. The
type/composition of the weight, is immaterial.

otn

otnmbrd wrote:
I'm going to print this out and read it thoroughly, but, overall, I'm
going to disagree.
Filling a fuel tank or beer cooler, down low in the hull, will
DEFINITELY increase stability. It's a question of added weights to the
hull.
Water Ballast, is a great way to add draft as well as stability, to a
hull (unless you leave the tank slack, in which case, the "free surface"
can outweigh the additional stability).

otn

Lloyd Sumpter wrote:

On Mon, 20 Oct 2003 18:02:00 +0000, DSK wrote:

Lloyd Sumpter wrote:



Tell me, is your boat's stability increased by filling a fuel tank
down low in the hull? Fuel is definitely lighter than water. How
about a big cooler full of ice & beer?



Compared to AIR, yes. Compared to lead, no. I'd show you the
mathematics if you feed me beer.


Math, huh? Do you do numbers any better than you do logic?

So... because lead ballast is better, as ballast, does that mean water
cannot function AT ALL as ballast?

No. Of course not.




Yes, it does.

(actually, it's physics, not math, but you owe me a beer anyway)

Draw a diagram if you like. Now, the keel imparts a righting moment on
the
boat because it exerts a downward force offset (in the x-dir) from the
center of rotation by the distance from the CofR (ie how deep the keel
is)
and the angle of heel. Problem is, a water-filled keel does not sink and
therefore exerts NO downward force in water! (actually it does sink a bit
because the fibreglass the keel is made from sinks. You'd be better off
with a solid fibreglass keel...) Remember the water-filled bottle?

People think that because water is "heavy" in air means that it's also
"heavy" (ie exerts a significant downward force) in water. This is simply
not the case. Imagine this: get a boat with no keel and a mast. Put a
rope
on the mast and pull on it, giving the boat heel. Now, put a boom out the
upward side with a bucket filled with water. As long as the bucket is in
air, it exerts a righting moment against the rope. But when it's in the
water, the only righting moment from the bucket is from the bucket itself
- the water exerts no righting moment whatsoever.

Now, having a water-filled keel that exerts virtually no downward
force is
still preferable to an air-filled keel, which exerts an UPWARD force.
Also, water in the keel will help the boat's "stability" in that it
increases the overall mass (F=ma) so movement is dampened.

But "ballast"? No.

Lloyd Sumpter
"Far Cove" Catalina 36

Lloyd Sumpter wrote:


People think that because water is "heavy" in air means that it's also
"heavy" (ie exerts a significant downward force) in water. This is simply
not the case.

True enough, but totally irrelevant. Which weighs more, a ton of feathers or a
ton of lead?

You are totally off base and your physics is wrong. Sorry to be so blunt. You
have no concept of what produces rightning moment; I suggest reading a good
simplified text on naval architecture, such as Robert Perry's book or Skene's
Elements of Yacht Design. Read the section on "metacentric height' two or
three times.

You point out that lead sinks and water does not. It seems to me that the
point is to increase stability of the boat, not to sink it. Wouldn't water
ballast be better, then?

If you like to paint imaginary scenarios illustrating how water functions as
ballast, then picture the following: a big ice chest full of cold beer. Take
it aboard your boat. The boat sinks a little deeper as the weight of the
cooler comes aboard, it's displacement has increased. In other words, the boat
is supporting the weight of that cooler & it's contents, wether those contents
are feathers or depleted uranium.

Now hoist that cooler to the top of the mast and try heeling the boat. Of
course, stability has been reduced, it will take less force to heel the boat
to any given angle. Now lower the cooler and place it as low as possible
against the bottom of the hull. Try heeling the boat again, of course you'll
find that stability has been improved. It will take more force to heel the
boat to any given angle.

Taa Daa!

A cooler full of ice & beer, which is absolutely lighter than water and does
not sink, has become ballast.

You're welcome.

Doug King

anony,

Everyone knows they are anti-flotation devices.

Regards, Ron

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On Mon, 20 Oct 2003 17:50:58 -0700,
Lloyd Sumpter wrote:
On Mon, 20 Oct 2003 18:02:00 +0000, DSK wrote:

Lloyd Sumpter wrote:


Tell me, is your boat's stability increased by filling a fuel tank
down low in the hull? Fuel is definitely lighter than water. How
about a big cooler full of ice & beer?


Compared to AIR, yes. Compared to lead, no. I'd show you the
mathematics if you feed me beer.

Math, huh? Do you do numbers any better than you do logic?

So... because lead ballast is better, as ballast, does that mean water
cannot function AT ALL as ballast?

No. Of course not.



Yes, it does.

(actually, it's physics, not math, but you owe me a beer anyway)

Draw a diagram if you like. Now, the keel imparts a righting moment on the
boat because it exerts a downward force offset (in the x-dir) from the
center of rotation by the distance from the CofR (ie how deep the keel is)
and the angle of heel. Problem is, a water-filled keel does not sink and
therefore exerts NO downward force in water! (actually it does sink a bit
because the fibreglass the keel is made from sinks. You'd be better off
with a solid fibreglass keel...) Remember the water-filled bottle?

People think that because water is "heavy" in air means that it's also
"heavy" (ie exerts a significant downward force) in water. This is simply
not the case. Imagine this: get a boat with no keel and a mast. Put a rope
on the mast and pull on it, giving the boat heel. Now, put a boom out the
upward side with a bucket filled with water. As long as the bucket is in
air, it exerts a righting moment against the rope. But when it's in the
water, the only righting moment from the bucket is from the bucket itself
- the water exerts no righting moment whatsoever.

Now, having a water-filled keel that exerts virtually no downward force is
still preferable to an air-filled keel, which exerts an UPWARD force.
Also, water in the keel will help the boat's "stability" in that it
increases the overall mass (F=ma) so movement is dampened.

But "ballast"? No.


How is that not ballast?


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