Kayak Skeg and Rudder

I purchased a Sail for my kayak and it works great unless you want to tack. I was wondering if there are formulas for size of skegs or rudders.

In thinking about the problem I was considering making a bow skeg made out of plexi-glass that could be rotated in the down position when using the kayak for sailing and rotated up when not in use and a stern rudder similar.

I didn't know whether these ideas go against marine design theory or not so I thought I would ask...

Thanks...

Fair Winds and Following Seas.....

 

Do you have a centerboard or leeboard?
You have to have something to keep you from going sideways when tacking, coincidentally that also acts as a pivot point for your rudder.
Rudders have to be bigger for sailing instead of kayaking, unless you have the sail and leeboard perfectly matched up.

A good place to go to see quite a few of those discussions would be at this web site: (ignore the fact they are sailing the wrong boats, it works the same)
http://www.songofthepaddle.co.uk/forum/forumdisplay.php?135-Canoe-Sailing-and-Sailing-Canoes

 

do not use a bow rudder or skeg, it will be destablizing and difficult to control. there is a reasaon those are not used.

for small sail boats the standard starting place is a lee or center board about 5 percent of the sail area, and the rudder about half of that.

The centerboard centroid should about line up with the centroid of the sail are when looking at a profile of the hull and sail plan.

There are various complex reasons that these simple ratios are changed but for small boats it usually works good enough to leave it. keep in mind that both the rudder and lee/centerboard will be taking large side loads from the sail and should be strong enough to not twist off their mounts.

keep the aspect ratio (length to width ratio) fairly low to resist stalling the surfaces and it should work out fine.

Also realize in a high cross wind you will need to counter blance the heeling caused by the wind on the sail, a short low sail would help, but you will have to put your weight off center to stay upright if you are not using your kayak with an outrigger or similar way to make like a tri-maran.

good luck.

 

You can also keep it simple and jibe instead of tacking.

 

oooh yuck ! In rough water you have to cross more wave troughs, in light winds you lose a boatlength or more in light airs, making windward progress really painful.

Leeboards will work ok, but most kayaks have long fairly long straight keels for directional stability, making sailing a bit less maneuverable.

 

What we used to do as kids in canoes was to use a paddle as a leeboard. If you are steering with foot pedals, stick one blade in the leward side and it should let you tack easier.