Knock Down Anxiety - SailNet Community
 6Likes
Reply
 
LinkBack Thread Tools
post #1 of 44 Old 10-04-2011 Thread Starter
Senior Member
 
JedNeck's Avatar
 
Join Date: Sep 2011
Location: Seattle, WA
Posts: 152
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 4
 
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...
JedNeck is offline  
Quote Quick Reply Share with Facebook
Sponsored Links
Advertisement
 
post #2 of 44 Old 10-04-2011
Midwest Puddle Pirate
 
US27inKS's Avatar
 
Join Date: Feb 2005
Location: Gardner, KS
Posts: 2,160
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 12
   
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.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
John USYacht 27 "Cora Lee"
US27inKS is offline  
Quote Quick Reply Share with Facebook
post #3 of 44 Old 10-04-2011
Senior Member
 
paulk's Avatar
 
Join Date: Jun 2000
Location: CT/ Long Island Sound
Posts: 2,609
Thanks: 4
Thanked 26 Times in 25 Posts
Rep Power: 16
 
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.
Sublime likes this.
paulk is offline  
Quote Quick Reply Share with Facebook
post #4 of 44 Old 10-05-2011 Thread Starter
Senior Member
 
JedNeck's Avatar
 
Join Date: Sep 2011
Location: Seattle, WA
Posts: 152
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 4
 
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.
JedNeck is offline  
Quote Quick Reply Share with Facebook
post #5 of 44 Old 10-05-2011
Senior Member
 
L124C's Avatar
 
Join Date: Oct 2007
Posts: 1,435
Thanks: 58
Thanked 6 Times in 6 Posts
Rep Power: 8
 
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.
L124C is offline  
Quote Quick Reply Share with Facebook
post #6 of 44 Old 10-05-2011
Over Hill Sailing Club
 
smurphny's Avatar
 
Join Date: Feb 2009
Location: Adirondacks NY
Posts: 3,543
Thanks: 88
Thanked 104 Times in 101 Posts
Rep Power: 7
 
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.
cb32863 likes this.

Last edited by smurphny; 10-05-2011 at 09:16 AM.
smurphny is offline  
Quote Quick Reply Share with Facebook
post #7 of 44 Old 10-05-2011
Senior Member
 
emoney's Avatar
 
Join Date: Jun 2010
Posts: 545
Thanks: 0
Thanked 1 Time in 1 Post
Rep Power: 6
 
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.
emoney is offline  
Quote Quick Reply Share with Facebook
post #8 of 44 Old 10-05-2011
Broad Reachin'
 
kwaltersmi's Avatar
 
Join Date: Aug 2006
Location: Grand Rapids, Michigan
Posts: 1,936
Thanks: 1
Thanked 17 Times in 17 Posts
Rep Power: 10
 
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.

Catalina 34

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
kwaltersmi is offline  
Quote Quick Reply Share with Facebook
post #9 of 44 Old 10-05-2011
Senior Member
 
dhays's Avatar
 
Join Date: Jul 2010
Location: University Place, WA
Posts: 662
Thanks: 3
Thanked 2 Times in 2 Posts
Rep Power: 6
 
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.

47*20'11.7" N
122*35'20.8" W
S/V Legacy, Catalina 400 MkII, Hull #328
My Blog on
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
dhays is offline  
Quote Quick Reply Share with Facebook
post #10 of 44 Old 10-05-2011
Barquito
 
Barquito's Avatar
 
Join Date: Dec 2007
Location: Madison, WI
Posts: 2,266
Thanks: 0
Thanked 27 Times in 27 Posts
Rep Power: 8
 
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.
Barquito is offline  
Quote Quick Reply Share with Facebook
Reply

Quick Reply
Message:
Options

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now



In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.


User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Forum Replies Last Post
Open Water anxiety NewportNewbie Learning to Sail 32 10-09-2011 12:47 PM
Sailing Anxiety (confession time) MedSailor General Discussion (sailing related) 21 09-21-2010 12:57 PM
T.I.A. (thread initiation anxiety) StickFoster Introduce Yourself 6 07-28-2009 03:30 PM
Keel Anxiety! Spang Boat Review and Purchase Forum 8 06-19-2006 03:09 PM
anxiety in buying a boat casey1004 Boat Review and Purchase Forum 35 10-29-2003 06:09 AM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome