Sail on a kayak?

[shoupart]

Has anybody done this?

I've thought about it and seen a few kits out there. It seems like the major problem is adding a centerboard or keel, that is still handy enough to be raised and lowered

[cmburch]

CLC kayaks has some diagrams of a retractable skeg that may give you some ideas. Outrigers are also used.

http://www.clcboats.com/shoptips/fitting_out/

[keyone]

.

[OceanEd]

Look at what Hobie has for theirs.