John,
I just can't fathom why you see yourself climbing over the stern of your boat. Wet reentries are generally made over the side. A stern mounted rudder is ideally positioned to be out of the way of a soggy paddler climbing back into his boat. Also, kayaks draw very little water and can be taken into very shallow areas which means that the rudder must be capable of being lifted so as not to be broken. Again a stern mount gives lots of room for the rudder to pivot upward without hitting anything.
A bit of personal lore. I had a 17 ft. Folbot that mounterd a 2.5 HP Johnson outboard. The only place to hang the motor was near the rear of the cockpit which was about 36-40 in. from the stern. Steering was a bit awkward because the boat wanted to go sideways while it turned. The only way to make the boat manueverable was to lock the motor straight ahead and hang a rudder on the stern.
Good luck.
Charlie

: Hi all,
: I'm in the process of designing an internal rudder. (I don't fancy climbing
: over one of those rear end things). I've just about got it worked out, and
: will post a picture of it when ready. There is one thing I'm mystified
: about and can't seem to find info on yet.
: What would be the best placement of the rudder? Would the same position as a
: skeg be the best, the last 18"-30" section, or is there a
: science attached to it?
: At what point would it exert the most turning force?
: Where would it be most effective?
: I think these two questions are distinct, but my physics knowledge went out
: of the brain years ago. Does anyone have an answer? Thanks in advance.
: John