Center-Board Finesse

[Sailing-Randy]

With limited experience in sailing, I am coming for ideas. I noticed yesterday that putting the board down only about half way, 45 degrees came me much better response. Is that common? Is something awry? Am I on the wrong board?
Randy

[Todd Bradshaw]

You may well find that various amounts of board work best in certain conditions or on certain points of sail. Lowering the board only part way can, in some cases, reduce drag (even by the fact that the angled board plugs more of the hole in the bottom of the case). It also moves the Center of Lateral Plane aft, giving the sailplan more lead and affecting the balance of the helm.

I've owned boats where the best performance was achieved by watching the boat's track and lowering the board just enough to prevent side-slipping. If the helm gets heavy, you give it a little more board until control returns. If you're trying to point as high as possible or getting ready to tack, the boat may do better with the board lowered all the way.

Since the wind, water conditions, sail trim and heel angle are constantly changing, the formula used by the designer to place the centerboard for best performance may be more accurate in certain conditions than in others and centerboard adjustment becomes one more tuning tool. If the controls that raise and lower the board are readily available and well designed to work smoothly - even under the kind of side-loading that the board gets while you sail, you might as well use it.

[dasboat]

Having zero sailing experience,I must say that these sailboat q & a's are facinating.
Thanks for the great explanations youse guys.
Lurking and learning on sail posts.
Darryl

[John R Smith]

Experimentation like this is obviously a lot easier to do on a little boat, say a 12 foot dinghy. With big 'uns like Norm's Prairie Islander, the actual effort involved in mucking around with the board tends to put you off a bit. Lulu's heavy iron centreplate has just a simple tackle, which makes raising and lowering quite quick, but also hard work.

John

[BrianCunningham]

Parker talks about board use in his book.

I like the part about using it as a "parking brake" while waiting for drawbridges to open!

He mentions running with the board up while traveling down wind.

As far as coming about, it depends on your particular boat. Since they board directly effects the center of lateral resistance. Sailing canoes & kayaks experiment with leeboard placement all the time, since they are readily moved.

[Todd Bradshaw]

Some small boats have a tendency to "trip" over their centerboards and broach when running downwind with the board down, especially faster boats (been there- done that - the T-shirt got wet). Since the more downwind your course, the less lateral resistance you need, pulling the board up also eliminates drag on a run.

Once you get into REALLY fast boats, like Aussie 18' skiffs they just leave the board down all the time. They don't have enough time to monkey around with the board and even downwind, the aparent wind is shifted so far forward that they are essentially still sailing upwind! Now that's a fast boat.

[This message has been edited by Todd Bradshaw (edited 10-02-2001).]

[Tim B]

Randy,

Dito to all that's been said already. You will notice different responses depending on wind strength as well. A little trick that i've learned for determining side slip is to look at the wake behind the boat. Does it trail off at the same angle on both sides? It's a good way to tell if your slipping or turning. You can experiment by centering the rudder and then adjusting the board up or down to sail a straight course. Sail trim also affects it. In small boat racing it is a crime to have the rudder not straight.

tim

[Ed Harrow]

And when those about you are hiking for all they're worth, shortening sail, and otherwise panicing, it's kinda fun to ease your board up a bit and carry on. Sure you'll make more leeway, but you'll have more fun.

[David Tabor (sailordave)]

And if you really wanna have some fun, lash the tiller amidships and sail using the sail trim, crew weight and centerboard/daggerboard trim to tack and change course!!!

[Sailing-Randy]

Thanks Guys for the helpful info! I am learning allot, my learning curve is still seems to be standing on end!You have given me much to consider, and I will continue to experiment.
Thank you!
Randy