Looks like a Mac capsized in RI

[John McDonough]

We are all still guessing. The real Facts have not yet been reported. (yet)

My guess still remains.. Motoring with Empty ballast, Sails up, centerboard down. I think if he had Ballast tanks full, he would of self righted long before enough water entered the front hatch..

It is possible he was motoring attempting to drain the ballast, so when he capsized, the Drain Valve open let water back into the tank. If you check the photo, the Drain Valve is underwater.

It is possible he was motoring with the Ballast tank empty and the Drain Valve closed. After Capsizing the captain may have opened the Ballast Drain Valve hoping to fill the Ballast tank. It is also possible that as he attempted to fill the Ballast tank, once the water level reached the Vent hole it would now empty into the Cabin until the boat flloatation balanced out and water level equalized.

[John McDonough]

Its also possible that he may have experienced a large hole in the boat causing the cabin to flood, but One would think it would stlll be in the Upright position., unless the Ballast tank was empty which would of caused the boat to roll onto its side..

[Kelly Hanson East]

Water in the tank is not bouyant and contributes to righting exactly as the equivalent mass of lead located such as the total moment of inertia (MOI= sum of the massXdistance from the COG) is the same. Water on the 'outside' of the tank cant tell if the mass on the inside is water, lead, rubber ducks, or left over blue hull paint. When something tips the boat, the

If the tank is partially filled, all bets are off, as now the water and its MOI are changing - usually with bad effects. Again, this has nothing to do with buoyancy.

[MARK PASSMORE]

Thanks Admiral Kelly Hanson. That’s what I was trying to articulate. But hey, what do I know…I’m just an Engineer.

[Currie]

Steph/Mark,

welllll....(my butt is clinching a little bit on the subtle difference here).

We're talking about flooded/partially-submerged boats in this case. It comes down to density as Don/MD and I pointed out. Any water ballast caught below the water line in a capsized/flooded boat is right-moment-neutral. Only the water-ballast above the water line in "counted". Not true for lead. The 300 lbs of lead in an 26M is there for a reason, and it is definitely not the same as 300 lbs of water ballast if the boat is flooded and on its side.

IOW - I can take 5 lbs of water and 5 lbs of lead and put them on balance, and the balance is level. If I dip them in the water, the balance tips toward the lead side, because the water side is "weightless" in water. The lead side weighs about 90% of it's original. This phenomenon is occurring in a flooded boat.

(unless we're actually agreeing and I'm misreading what your saying )

~Bob

[Chinook]

If you have a canoe, it's easy to demonstrate the effects of "water ballast". I've been in my canoe on the river and taken in a large quantity of water by plowing into a standing wave. With 6 inches of water in the canoe, it behaves much differently than when empty. It sits much lower in the water, but since this water isn't contained, like the water in a Mac's ballast tanks, it's free to seek its own level when the canoe lists to one side or the other. It's possible to keep a partially swamped canoe upright only through an extreme act of balancing, and you're definitely going to roll over very soon. The canoe feels and behaves like a waterlogged log. It just wants to roll over. I suspect that if you managed to badly swamp an X, even a fully ballasted one, she would really want to roll over. Only that portion of the water ballast raised above the water line would have righting moment. At best, that would only be half of the ballast (700 lbs), and in practise, probably much less, since the boat would be sitting much lower in the water. When you consider the weight of mast, boom, sails, and other stuff which would be wanting to pull her over, it's pretty easy to picture the boat not righting herself.

[MARK PASSMORE]

Question: If a person took a five gallon bucket and filled it full of water and then sealed the bucket with a lid. Then sunk the bucket to the bottom of a pool. Then swam down to get the bucket off the bottom. Would the bucket be heavy? Now if the same person filled another five gallon bucket but didn’t seal it with a lid and repeated the process would that bucket be as heavy as the first bucket?

[Kelly Hanson East]

Mark has exposed the 'disagreement' above

Some of us are talking about the effect of ballast in the tank and some are talking about water stuck in the boat from flooding.

The important thing to grasp is that even though water in the tank is neutrally bouyant, the fact that you put it in the tank makes it useful to right the boat, regardless of its position relative to the waterline. If you put in a less dense than water material in, like gasoline, it would also act to right the boat...... briefly, until the ensuing fire turned the boat into FG chips.

Water in the cabin can work to either right or tip the boat as it sloshes around...complex behaviour. Its moment with respect to the centre of mass is constantly changing, so you cant make sweeping statements about how it will act.

[Russ]

Question: If a person took a five gallon bucket and filled it full of water and then sealed the bucket with a lid. Then sunk the bucket to the bottom of a pool. Then swam down to get the bucket off the bottom. Would the bucket be heavy? Now if the same person filled another five gallon bucket but didn’t seal it with a lid and repeated the process would that bucket be as heavy as the first bucket?

When you say "Would the bucket be heavy?" do you mean lifting it above water or off the bottom of the pool?
Because the bucket would be fairly neutral in both situations save for the weight of the bucket itself and the water resistance the bucket provided.

The canoe example above is excellent to understand how water sloshing around, either in the cabin or partially filled ballast can make a vessel unstable. Now if you could keep that water weight fixed as in the fixed ballast of the M or a properly filled ballast tank, it would have righting power. See "weebles wobble but they don't fall down". You can turn a weeble upside down and it will right itself. But weebles don't have water and gear sloshing around in their cabins either.

Another factor is the Mac isn't round like a weeble or the illustrations above. Once you get her on the side, the Mac has a new flat surface to act as the new "bottom". A typical rounded sailboat would be more likely to come back up with even a small amount of righting weight.

--Russ

[Currie]

Mark has exposed the 'disagreement' above
The important thing to grasp is that even though water in the tank is neutrally bouyant, the fact that you put it in the tank makes it useful to right the boat, regardless of its position relative to the waterline.

Total agreement here on that. If it's filled with air, that's really bad. I was responding to "water ballast is just like lead ballast". That's not true.

[Hamin' X]

To demonstrate what Steph is talking about, you need to do an experiment. Take a large diameter length of PVC pipe (4" is big enough) about a foot long, with end caps and draw a straight line down the length of it. Next, you need a length of one inch pipe with caps that will fit inside the big pipe, when all caps are on. Also, a small amount of lead, like wheel weights.

Weigh the empty small pipe and caps. Fill the small pipe with water and put the caps on (do not glue). Weigh the pipe with water in it, subtract the empty weight to obtain the weight of the water and cut an equivalent amount of wheel weight.

With caps on, place the empty large pipe in a tub of water and rotate it about the longitudinal axis. The line that you drew should show now preference as to where it stops.

Weigh out a quantity of water that equals the weight of the water filled small pipe and pour this into the large pipe and place the caps on. Float this pipe in a tub and rotate it about the longitudinal axis. It should rotate slightly slower, due to the friction of the water flowing inside, but still should not show a preference to which side stops in the up position.

Next, secure the small, water filled pipe inside the large pipe, with a small amount of silicone caulk, or similar. Repeat the experiment above and you should find that the water filled pipe always returns to the bottom.

Repeat above steps with the lead inside the small pipe, instead of water and the results should be similar to having the water filled pipe.

The results should change if you partially fill the large pipe with water and the water filled small pipe should lose effectiveness, as long as it remains below the waterline, while the lead will remain effective.

Obviously, the experiment could be expanded to include the masts and sails and you could measure the effort to heel the large pipe.

~Rich

[MARK PASSMORE]

I was trying this experiment tonight but my friend Mr. Miller keeps messing me up.

[MD Dunaway]

A simple experiment with the only things I could find in the kitchen that would work.

In the bottom image the film container is full of water. It acts as ballast and keeps the jar from rotating (unless I rotate it enough to make the film container roll).

In the top picture the lid was removed and the jar flooded. The film container is still full of water. The film container now floats with just the minimal amount of buoyancy that the plastic in the container itself provides.

The water is neutral but the plastic floats. What if it were even an eighth full of air? Is there any chance that something that floats will provide any ballast?

If the water were in a container that was more dense than water it would sink and provide just as much ballast as the weight of the container itself would provide and the water would contribute nothing.

[ROAD Soldier]

Hence the term when weather gets rough batten the hatches and put you companion way door in.

[curtis from carlsbad]

Seems easier just to go surfing than to try to figure out what the hull happened.But what do I know? I'm just a floating Great White sharkbait.I gotta lot to learn about this boat.I'm so green that on St. Patty's I don't even need to slap on a green shirt.So don't listen to me.I'm glad some of you with some brains on this site are figuring this thing out.My brain after 19 hours of cab driving isn't much better than my morning mush.So it's nice to just get home,click favorites onto this website,and let all of you do all the hard thinking.I'm just riding the coattails of your collective cosmonautical superprowess.You guys are just plain bitchen! Sincerely-Curtis Becker Ps:I still haven't figured out a tow vehicle yet but I did buy a (Gumba)(Good Fellows looking)Lincoln Towncar for my ramshackle,fledgling limo business.No penguin suit yet.I'm dressing like a cheap (Billy Mays wannabe)infomercial mop salesman but about 3 times better looking.Even better looking than Sham Wow Fitz-HONEST!I better go to sleep .See! this is what too much cab driving can do to a poor working stiff. But don't feel sorry-PICK YOUR RATE,PICK YOUR FATE.(I'M ACTUALLY HAPPIER THAN I'VE EVER BEEN IN MY LIFE) Okay guys I'll shut up and go to sleep.