DSK wrote:

In other words, the boat is ballasted with a lot of mass far forward,
as Jeff was contending earlier.



JimC wrote:

I never stated that the ballast mass is "far forward", DSK, and I
don't think Jeff did either.


If Jeff didn't, then why were you arguing with him over that exact point?

Jeff had said that the ballast extended the entire length of the boat.
It doesn't, and the ballast tank itself extends about the same distance
forwardly and rearwardly from slightly forward of amidships. You need
to remember that the ballast tank is tapered (both vertically and
laterally) as it approaches the bow. Thus, their is very little mass
near the bow, and the largest volume (and greatest mass) of ballast is
concentrated forward of amidships.


... As to the moment of inertia during pitching, the motor, after all,
is about the same weight as a crew member


A very very large & well-fed crew member.


By way of perspective, there may be several crew members and/or guests
in the cockpit, weighing far more than the motor. Though the motor is
slightly to the rear of the cockpit, the weight of the
crew/skipper/guests (when guests/crew are onboard) is by far the
greatest weight factor. And the boat is designed to be balanced and sail
well with such a load.


... and though its slightly aft of the cockpit


In other words, it is as far aft as it can be, and still be part of the
boat.



.... its weight (mass) is not a great factor, as some of your buddies
claim. (As previously stated: "I doubt seriously that the weight of
the motor is a major factor.")


Whoever stated that is an idiot.
It's 200+ pounds at the farthest aft extremity of the boat. You want to
claim this doesn't affect pitching moment "very much" whereas
knowledgable sailors know that weight in the far ends of the boat is bad
for steering & worse for pitching. Not a "major factor?"



Sure thing DSK. - Whatever you say. The motor is about a foot behind
the skipper's seat, so I'm sure that must create lots and lots of
problems. In fact, the Mac is built with a wide (but not "huge", flat
bottomed") hull, extending from amidships to the stern. - It's not a
canoe hull, and it doesn't taper toward the stern as in the case of some
boats. Pitching isn't a problem, Ganz.





Between the ballast far forward and the engine wieght far aft, it's
hard to imagine a worse set-up for good sailing performance.


Actually, of course, the ballast is centered slightly forward of
amidships, as already discussed. Additionally, there is several hundred pounds of fixed ballast amidships.
In a boat such as the 26M with wide hull, 250 lb., is of little consequence.


Yeah, I bet you can carry it with one hand.

"Of little consequence" except for the boat's poor steering & worse
pitching.

Really? And what's your experience sailing the 26M? How many hours? It's
always interesting to me that those who are the most adamant in their
condemnation of the boat are the very ones who have never sailed one.


Does the weight of the keel affect pointing? Funny, I always thought
that had to do with the basic rig design... aspect ratio, sheeting
base, etc etc... keel foil configuration plays into it somewhat I'm
sure, but how does the wind know (and why would it care) about the
weight of the keel?

A conventional boat with deep, heavily weighted keel can stand up to
more wind than the Mac before reefing, and since more sail can be let
out proportionally to the size of the boat, the conventional boat has a
greater forward force vector than mine. Thus, the conventional boat can
generally carry more sail, proportionally, and sail faster upwind. Also,
since the conventional boat can stand up (more vertically) to the wind,
the keel serves more efficiently to minimize lateral movement of the
boat, keeping it on a straight, upwind course.



As you probably know, a weighted keel positioned five or six feet
below the hull entails more leverage


Which does *what* exactly, for POINTING?
Please explain.


A boat with heavy weighted keel remains relatively upright even with
lots of sail out, it can therefore be sailed faster upwind. Without the
weighted keel,the boat tends to heel to a greater extent, requiring
reefing in earlier and to a greater extent, thus lessening it's forward
speed while pointing. I'm not saying that the Mac doesn't sail well
upwind, but it doesn't sail as well upwind as larger, heavier boats. In
a boat without sufficient ballast, the boat heels and develops weather
helm, forcing it into the wind. It can't sail upwind very well if
pointing directly into the wind.


.... provides a more efficient righting moment than the same weight of
ballast,particularly water ballast, positioned within the hull.


Why "particularly" water ballast? Does gravity care if a ton of ballast
is water or lead or feathers?

Yes, actually it cares a lot, DSK. - Because if the ballast is a ton of
lead, which of course is substantially denser than water, the necessary
ballast will be substantially smaller than water ballast of the same
mass. Therefore, it can be positioned lower in the hull, making it more
efficient, in that the center of mass is lower (and the "lever arm" is
longer). Or, if desired, more lead ballast can be used within a given
space, for providing still more stability.


.... For its size, it a deep, weighted keel is more efficient in
keeping the boat in a nearly upright position as winds increase,
permitting more efficient translation of the force of the wind into
forwardly directioned forces.


That may help it's speed, but how will it affect the boat's pointing?

As previously discussed, if the boat heels excessively because of
insufficient ballast, it would tend to round up into the wind and loose
speed. Boats with deep, heavy keels are less susceptible to the problem.
(Incidentally, DSK, it seems to me that, instead of making me prove in
infinite detail why the Macs don't point as well, you ought to jump on
this as a negative factor in the Mac that I have acknowledged. - Whose
side are you on anyway?)


... The aspect ration of the keel is, of course, also a factor in
preventing lateral "sliding" of the boat,


No it isn't. The aspect ratio is a factor in the expected lift/drag
ratio of the foil.

The total amount of lift generated by the foil determines the leeway or
lateral sliding of the boat.


I'll agree with you on that one. The narrow keel provides greater
maneuverability, but not more lift.


.... and the Mac 26M has a retractable dagger board that is quite narrow.


Meaning what?

It helps the boat maneuver more efficiently.

You started out to explain pointing, and so far you've fumbled around in
the dark in left field.

You *almost* mentioned something that might be
related to pointing, but you got it worng anyway.


Sorry to disapoint you DSK. But the boat is still lots of fun to sail.


... To compensate for the relative inefficiency of the water ballast
as compared with a heavy,weighted keel, the Mac has a total ballast
sufficiently large to keep the boat upright. After years of mods and
improvements, the current model, with appropriate reefing, sails
well in pretty heavy weather. (For example, mine was heeling at
only 20 degrees Saturday in 15 knot winds, with the first reef taken in.)


And what was your VMG to windward?

I'm assuming you talking about velocity over ground? - Around 6 knots or
so with the main and jib reefed. - I was sailing solo, and didn't want
to let it heel more than around 25 degrees.

Best speed on a reach? If the wind is
strong enough to reef, then you should be able to plane.

You say the boat sails rather well, my observation (many times over) is
that they sail poorly. Almost any decent sailboat will beat them
downwind and a potting shed will beat them upwind.

Once again, DSK, I didn't buy the Mac because I wanted to race it. - I
bought it to enjoy sailing, cruising, etc. How many times do I have to
repeat that? If all you are interested in is "beating" other boats, you
have a ****-poor understanding of the joys of sailing IMHO.


Are you tacitly admitting that Mac-26Ms don't sail to windward very
well? We already know that's true of the M26X.



No I'm not tacitly admitting anything. I'm stating opently (once again)
that they don't sail to windward as well as conventional sailboats
with weighted keels. It's one of the compromises of the design.


So... we can agree it sucks at sailing to windward.

Nope. It doesn't suck sailing to windward. But it doesn't do as well as
some others.

Do you think perhaps the weight of the motor... and the huge flat aft
sections necessary to float it... have anything to do with that?


I've had mine two years, DSK, and so far I haven't seen any "huge, flat
aft section," Where exactly is it?



Actually, if you're reefing & heeling & all that stuff, it must be
almost the same as sailing.You mean, the experience of sitting on a boat
with sails up? Pity you need that huge motor to actually go anywhere.

Cute DSK. But rather childish. - And, you have sailed the 26M how many
times?


BTW many sailboats will go faster than 13 knots.

I'm aware of some that will, but most don't do it very often. Or were
you talking about going down off a wave?

... Rather, it's the compromises relating to the internal ballast,
trailerable hull, and lack of weighted keel. (The metactric effect.)


Please explain. I know about metacentric height, but have never heard
of "the metacentric effect."


The metacentric height is considered the distance between the center
of gravity and the metacenter. By "metacentric effect", I was
referring to the fact that the righting force is proportional to the
metacentric height times the sine of the angle of heel. Thus, a
conventional boat, with weighted keel low in the water, would have a
lower center of gravity than the Mac and would therefor tend to be
less tender.


Good, but not quite right. The metacenter is figured as height above the
waterline. A lower center of gravity doesn't affect the metacenter at
all, it is strictly a function of hull shape.

Actually, I think you may be wrong there. I'll try to get the materials
I was quoting.

Shall I explain curves of righting moment? It's a key to understanding
how different boats sail differently... nah, maybe some other time. For
now, let's just say that there are effectively 2 forces producing
righting moment, one is the hull shape which produces initial
stability... how tender the boat feels when you step onto the gun'l from
the dock, for example... and the other is reserve stability, which is
affected by how low & heavy the ballast is, and produces righting moment
at high angles of heel.


... Again, the Mac 26M does entail compromises, but after a number of
years of development and modifications, it does the job. (If it
didn't, I would have capsized Saturday in the 15-knot winds instead of
sailing along with a 20 degree heel.- Right?


The fact that the boat doesn't fall over helplessly in 15 knot winds is
good, agreed.



No, the 2M isn't flat aft.


I guess it depends on what you call "flat."
http://www.improb.com/airchives/pape...i3/kansas.html

The hull of the 26M has a sharp V contour extending forwardly from the
stern, substantially greater than that of the 26X. Perhaps you were
confusing it with the older model.



... In contrast with your statement, it does plane easily and smoothly.


Then why won't it plane under sail?
Lots and lots and lots of boats plane under sail. It has been known how
to design sailboat hulls & rigs to plane since 1928. How the heck modern
can the Mac 26 M be if it doesn't incorporate this concept?

Lots of boats plane under sail? - Does that include lots of family
cruisers with standing headroom, queen-sized berth, high freeboard,
capable of being stored on a trailer, etc.? - I once had a Lido that
would plane. It didn't have a cabin, or a head, or a galley, however.



And just where did I say that the Mac 26M is a "sooper-dooper hot
performing sailing machine", or anything of the kind?


Well, lately, you've been admitting that it's slow. But hey, that's of
no consequence, just like the increased hobby-horsing due to the weight
of the engine on the transom.

And you have sailed the 26M how many times?



... I've said that the Mac 26M is fun to sail, but I have consistently
stated that it doesn't sail or point as well as a large displacement
boat.


Or a small one.

... Instead of saying the Mac is a great sailing machine, I've said
that it has limitations and disadvantages when compared with
conventional vessels.


It's all about compromises.


Do you consider lying about what I said, as you just did, a necessary
evil acceptable when convenient, DSK?


I haven't lied at all. You however have not only lied but also
contradicted yourself a number of times.

You didn't lie, DSK? That in itself is another lie. - I have never said
that the 26M was a "sooper-dooper sailing machine." I have consistently
admitted that it entails compromises.

- Incidentally, could you please cite ten incidences in which I have
lied? Or if you can't find ten, how about five? Two?

Why is that necessary to defend
your boat?

Because discussions of the Macs on this ng have been too one-sided and
need a little balance. There is also the matter of the possible damage
to the reputation of the MacGregor company, one of the great
manufacturers of modern sailing craft caused by comments from people
who, for the most part, have never sailed one and don't know what they
are talking about. Also, quite frankly, I get a lot of enjoyment seeing
some of the Mac-Bashers becoming increasingly frustrated and embarrassed
at not being able to put me down.

Those condemning the Macs on this ng in the past have been ridiculously
ill-informed. (And, once more, it's nearly always those who have never
sailed a 26M who are the most critical and the most dogmatic in their
opinions.) So I intend to continue providing some balance to the
discussions from time to time, as my schedule permits.



... Do you have no self-respect whatsoever, DSK?


Of course. I also have a lot of fun sailing, only not on a Mac 26 M or X.

I am glad you enjoy sailing your boat. That's what it should be all about.

I also enjoy sailing other boats, DSK.

Jim