This is a simple way to rig a sail for a kayak and one that can be used in kayaks with no rudder. I hope the drawings help understand how the sail is made and rigged (you can always give me a call on (02) 9181 2468).
Note that the way the cloth is stapled to the timber rod creates a small slot into which the tip of the paddle is inserted. The paddle is held upright with one hand with the bottom blade held between the thighs (no, its not painful). Steering is achieved by tilting the paddle to the left or right.
I tried this sail on my big plastic chinook and worked well downwind and on a very broad reach. But the biggest surprise was to try this sail on a little Minnow. In less than 10 knots of wind, the Minnow sailed faster than when paddled and it was easy to steer around moored boats.