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Is a Mac Knock Down fact or Fiction?
Posted: Wed Sep 28, 2005 8:26 pm
by richandlori
This question is always being brought up, the "possibility" of a knock down. The question I have is simple: has anyone here ever had a Mac knock down?
First I guess we should define the term. I would define a knock down or the event of a knock down as such:
The boat heals more that 45%, which results in a loss of boat control which the captain deems to be a truly dangerous situation. (It should be noted that I am assuming that the ballast is full, as Mac warns that it should be while under sail)
For all the "worry", I wonder how often it happens?
Rich
Posted: Wed Sep 28, 2005 8:53 pm
by jetta01
Rich, you might want to clarify the question more by saying a heel of > 45 with the water ballast full. We ended up with the engine out of the water, so much more than 45 degrees, but I think it was our fault for not having the proper amount of ballast. So to be fair to the Mac, the question should be qualified.
Posted: Wed Sep 28, 2005 9:54 pm
by richandlori
Yikes, Rick and you were able to Molly back on the boat? We should meet in Oxnard, let the girls hang out on one of our boats in the Harbor and we sail the other one out to Anacapa! That could make all of us happy.
Rich
(did you ever move your boat to Oxnard?)
Posted: Thu Sep 29, 2005 3:55 am
by Catigale
Never been close to this point. Worst I ever got into was about a 45 degree heel when I came onto a beam reach from a run in about 20 mph wind with full main and 150 genny...Catigale just rounded up with a big WOOSH...
kids held on for dear life
Posted: Thu Sep 29, 2005 4:17 am
by craiglaforce
Yes, been knocked flat about 2 times. Very sharp wind fronts hit in front of storms and the boat goes straight over. Not sure what the wind speeds were, but they were very high.
It is a very good idea to have everything secured below, or it will go crashing across the cabin. If you see the front coming, get those sails down and motor home, or at least let the front pass, before trying any sail again.
Posted: Thu Sep 29, 2005 5:39 am
by Mark Prouty
With that high freeboard, in a high enough wind, she'll heel 45 degrees without sails.

Posted: Thu Sep 29, 2005 5:43 am
by Dan B
Happened to me just once. Bright sunny day, blue skies, stead winds around 10 knots. All of a sudden, a strong burst came along from over the tree tops and pinned the boat down with water up over the windows for a few seconds. Ballast was in, as always.
Posted: Thu Sep 29, 2005 6:48 am
by Rich Smith
I've approached a knockdown quite a few times but every time the boat gets to about 42 degrees, rounds up into the wind, flattens out, and stops... I must say that I'm glad for this feature although I sometimes wish it wouldn't heel quite so easily...the solution: reef early, reef often!
Posted: Thu Sep 29, 2005 7:35 am
by RandyMoon
I got nailed one time. Wind was fairly strong and I stalled while changing direction. I didn't see the inclinometer because I was clinging to the pedestal with hands and legs. The boat leaned port and hung there for what seemed like a long time (4 or 5 seconds). It really freaked the Admiral out. Me too.
Next few trips out, I kept the mainsheet in my hand with lots of adrenaline in my bloodstream. The Admiral stayed freaked out the next several times out.
That is why my next project will be a single line reefing system so I can reef quickly. And I would be interested in some additional keel weight to make the Mac less tender in the wind.
That is why people are foolish for sailing without a life jacket. You never know what will happen.
Posted: Thu Sep 29, 2005 7:50 am
by ALX357
not in a monohull, but i have been knocked down twice on a Hobie 16, not much of a problem normally, but it turtled. Quite an eye-opener when you are sideways, gravity coming from the wrong place.
With the Mac, i think the large hull against the wind would aggravate the problem, in a microburst.
Posted: Thu Sep 29, 2005 8:41 am
by McSkipper
I tend to err on the side of caution. I understand that is no guarantee but it has kept our

from going over more than 45 degrees. We have had the rail close to the water in a race in Long Beach. I'm not sure whether we were going faster forward or sideways at that time.

Posted: Thu Sep 29, 2005 8:42 am
by Dan B
I sail fairly conservatively otherwise the crew (family) won't go. I reef early, keep the motor down whenever near a shore, assume other boats don't know rules of the road (assuming the larger boat always has the right of way), and let the Admiral keep the mainsheet in her hand to give her a sense of control. I mus say, though, after about 3 years, the kids have gone from screaming "their is water in the windows" to "wheee!" and not being bothered a bit.
Posted: Sat Oct 01, 2005 5:13 pm
by Idle Time
I've had it over to 45 degrees. Jim had just gone below to clean up all the stuff I slid off the table on the previous heel. He was eyeball to the level. I released the main and it popped right back up and kept on sailing..great Day on the water!! What a way to get your cardiovascular exercise.
Posted: Sat Oct 01, 2005 5:16 pm
by Idle Time
in my previous post I meant I "eased" the main. When I am in that kind of wind I have the mainsheet in hand and ease it in and out as needed. I kept it on a pretty good heel for quit awhile. I was having such a good time I didnt want to stop long enough to reef. Jim is getting pretty good at cleaning up after me. I wonder why he hasnt caught on to why I like to be at the wheel while under sail and he can be when we power. LOL
Posted: Sat Oct 01, 2005 5:44 pm
by Scott
I like sailing in heavy winds, my wife doesnt. I've laid mine over a bunch by myself, never with the wife but were working up to it.
As far as knockdown is 45 deg the official point of knocking down?? They tend to round up before then. My lean-o-meter is broke so dont quote me. They dont hold an edge as well as a full keel boat, the twin rudders towards the chine tend to make up for some of that.
P.S. its not really too hairy if the wind is consistant and you work up to it in stages. Just go out in increasingly strong winds and keep it sheeted. The ones that are hairy is a puff that you dont notice comeing and it puts you over really fast. Makes you spill your wine. Knocks the Caviar off of the table. Sullies the Croisants.
Afterthought I've never actually had the windows in the water and I've never put water over the combing in a Mac. I cannot say the same for near every other monohull I've owned or sailed.
Thought after the afterthoughtThe only sail that I've dragged in the water on a Mac is the Asymetrical. Cant say the same for the other mono's, we would usually drag the end of a boom a couple times a season.