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  #1  
Old 10-04-2011
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Knock Down Anxiety

Is there an...
(X sail area + Y windspeed) -Z ballast = 1 knockdown
...formula???

I have had my Cal21 heeled over pretty good, 45+ degrees...but the wind around here seems "gusty". I have had to dump the wind on a few occasions where I was heeled to my comfort level and then some and got hit with a gust.

I sail a small lake and I seem to get pulled over more and more the closer I get to shore.

Ease a new sailors mind...
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Old 10-04-2011
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Not much beyond 45 degrees and the boat will just round up. A real knockdown is hard to do without the help of a spinnaker.

Labor day weekend fun. I'm on the bow.
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Old 10-04-2011
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There's a formula, but it involves about ten more variables than you've mentioned so far. The easiest thing to do is what you've done: dump the wind. It also helps to keep an eye out on the water for dark areas that indicate puffs, and luff up into them. Lake sailing is likely to be gusty because of the downdrafts that slide down surrounding hills. Keeps you on your toes. Being aware of where the gusts are stronger is "local knowledge" to use when you're racing.
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Old 10-05-2011
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So with wind only the boat will round up before it goes over? Regardless of the amount of sail up? Even with the full main and the 160 genoa?
The Cal21 is a "swing keel". It pins down and weighs 360lbs. The boat weighs 1100#. It has 196ft of sail.
The lake doesn't get any wave action to speak of. Maybe 1' white caps in the worst of storms. The wind will whip up to 30+ at times though.
I just don't want go for a swim or hurt someone or break her...I her she won't forgive me for a while.
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Old 10-05-2011
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A 160?

Quote:
Originally Posted by JedNeck View Post
So with wind only the boat will round up before it goes over? Regardless of the amount of sail up? Even with the full main and the 160 genoa?
The Cal21 is a "swing keel". It pins down and weighs 360lbs. The boat weighs 1100#. It has 196ft of sail.
The lake doesn't get any wave action to speak of. Maybe 1' white caps in the worst of storms. The wind will whip up to 30+ at times though.
I just don't want go for a swim or hurt someone or break her...I her she won't forgive me for a while.
If you are in winds where you are concerned about getting knocked down, why would you have a 160 up? That almost IS a kite! Your sail size should be determined by conditions, and a 160 is for light air. Don't know the boat, but I would guess the 160 should come down as wind speeds go above 10 knots, certainly before you see white caps. Not only is it dangerous to be flying too much sail, it's hard on you, the boat and the sail. Until you know the boat, and what you are doing, I would err on the side of caution, and trim for the gusts. Go with smaller headsails and reef early. The goal is to keep the helm in balance. Then...if the boat isn't moving fast enough, shake out the reef, and/or put up a bigger headsail.
As others have said, learn to read the water. You can see gusts coming, and blow the main, or point the boat up to depower the sails. Then... fall off (back on course) when the gust passes. Lastly, realize that as the boat heels in a gust, the sails depower (and the keel has more righting effect), as less sail is presented to the wind. This, combined with the fact that the boat should head up due to weather helm, provides two safety factors (unless you have a 160 up in 30 knots)! You can also depower your main (thereby, making it more efficient in higher winds) by making adjustments prior to reefing. A great little book I highly recommend is "Sail & Rig Tuning" by Ivan Dedekam

Last edited by L124C; 10-05-2011 at 06:31 AM.
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Old 10-05-2011
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From the perspective of a single-hander, would never want to think that the wind could NOT knock me down with ANY sail set. The wind can do all kinds of unpredictable things, especially in lakes or amongst any high profile shore topography. Time of day, developing weather, land cooling/heating effects...all can add up to higher-than-expected wind. The key, as mentioned here, is to keep your eyes open, know what the boat does as the wind increases, and make it s.o.p. to reduce sail early. It's nice to see that 160 up but it can get you in trouble pronto. I have now decided my 100 working jib is always the sail to start with. It works best in almost all conditions. My 160 goes up only if I am really sure the winds will be light. The large headsail not only increases the danger level, it will also almost immediately create too much weather helm once the wind gets >10 knots, does not roll very well, and creates significant wind surface when furled. I have decided that for cruising, less is more.
Remember once your boat is heeled over enough to limit your ability to ease the mainsheet to dump wind, your only diminished option is to head up. At the rudder angle in that position, this may be impossible, especially with a small, modern spade rudder.
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Last edited by smurphny; 10-05-2011 at 09:16 AM.
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Old 10-05-2011
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I think, like others, that it seems like you're flying too much canvas for the wind. On a side note, I remember when I was younger in my sailing career and it seemed like I was heeled almost perpendicular to the water, when I was more likely no more than 30 degrees. The more I trusted the boat, the "safer" I felt. Lakes can be gusty, especially when they're surrounded by hills, so less sail, reef sooner than you think you should and have a great time. Good luck and be safe.
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Old 10-05-2011
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If you're not seeking thrills, try reducing sail area (sail change, reef, etc.) if you feel a knock down is a possibility. A knockdown in a dinghy or other small open boat (Laser, Sunfish, etc.) is one thing, but getting knocked down in a keel boat or 1000+ lbs swinger like yours can be scary and dangerous.
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Old 10-05-2011
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In many ways, a Cal 21 is much like a dinghy. In the type of wind that we get here in the PNW, you just always need to be prepared to dump the main or anticipate the gusts and come up into the wind a bit to reduce the effect. There is nothing wrong with releasing the traveler or the Mainsheet to spill wind.

I agree with the others that such a large headsail in those conditions is a bit of overkill. You will just be working a lot harder than you need to, and you will actually sail slower than if you had a smaller headsail up. Now, I'm guessing you don't have a smaller headsail, but that is something to think about for the future.
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Old 10-05-2011
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I had a Catalina 22 that, in my opinion, sailed like a keel boat in light and moderate conditions, and sailed like a dinghy in a good breeze. And, yes, you certainly can be knocked down. After I sold my C22, the new owner had a knock down, and sank the boat (open hatches probably).

"When in doubt, let it out." Applies to mainsheet trim and most interpersonal situations.
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