I agree with the dagger comes straight out from the top, center board swivels down from with in. The theory that a centerboard is one that is in the center of the hull does not seperate itself from a daggerboard, which is in the center on the I20, my 18SX, my Laser, and my old sunfish.

Why is it called a "centerboard" if it can be located any where on the vessel. I'll agree that a centerboard pivots, but if it can be located anywhere on the vessel why isn't it called a "swing board" or "pivot board"???

Ex: the mast on a catamaran is located where??? On the centerline of the vessel. The boards on an I20 maybe on the cenerline of the hulls but that is different then the "centerline" of the vessel. My P19 has pivoting/swinging boards but they are not on the center-line of the "vessel". I remember a definition from "Power Squadron" classes that a centerboard trunk was located on the "keel-line" of the traditional monohull sailboat.

Maybe the issue is that when "centerboard" was origonally defined nobody thought of a Catamaran.

HarryMurphey
H18mag/#9458, Fleet54/Div11
P19mx w/spin /#86, CRAC

I would be inclined to think centerline of hull(s) not vessel.

I agree that daggerboards go in a slot and centerboards pivot, but there are always exceptions and inconsistencies. Many scow classes have bilge boards. Since the boats are designed to be sailed heeled they put a board on each side of the boat that will be the lowest point when heeled at the optimum angle and the board is vertical in the water at that heel angle. In addition the board has toe in to reduce leeway. All the classes I'm familiar with use pivoting boards.

http://144.92.9.188/hoofers/sailing//Manuals/The%20Scow%20Manual.htm

There are also leeboards. Most of the examples of these that I've seen or read about are pivoting. I believe that I've seen lee daggerboards on smaller boats where you would just have one blade that you move from one side of the boat to the other.

http://en.wikipedia.org/wiki/Leeboard

John

Thanks John,

Maybe I should call the "boards" on my P19 Bilge boards as that seems to be the closest definition that fits as Wikipedia defines a ceterboard as being on the boat's/vessel's symetric axis. which sounds like somewhere in the middle of the tramp to me.

HarryMurphey
H18mag/#9458, Fleet54/Div11
P19mx w/spin /#86, CRAC

The wikipedia definitions for both centerboard and daggerboard were obviously written by a monohull person. <img src="http://www.catsailor.com/forums/images/graemlins/smirk.gif" alt="" />