rudder steering for rowboat

I periodically hunt motor-less lakes and have noticed that angling into or with the wind causes me to row almost exclusively from one side of the boat. I'd like to be using both oars almost all the time and thought there must be a way to rig up some foot-controlled rudder that can clamp on the transom. Most of the year if I fish or hunt waters that allow it, I use a 3 hp evinrude but have to take it off for the motor-less lakes.

Does anyone have any suggestions on how to build something like this?
Or is there an aftermarket gadget that can just clamp on the back of the boat?

Drawings would be helpful. If anyone has any ideas, I'd greatly appreciate it.

-Thanks
Eric

This is an aluminium, stationary rudder from one of our sponsors...Fish on fabricators I think? (correct me if I'm wrong) They will build to your specifications.

That's neat and all, but how does a stationary rudder help me steer the boat?

I don't think a rudder will help. Wind will still push the bow of the boat around because you are going too slow to create sufficient forces for the rudder to overcome the wind. If you're going .5 mph and the wind is blowing 5mph...the wind will win every time.. A keel helps a boat track in the wind.