Gareth,
Intersting concept.
Obviously it would need some work to refine.
Got me thinking could even replace the line with thin flat rod down the centre of the rudder.
When building the rudder a slot could be made down the centre to accomodate the rod.
Now if you can control the rod from the top you would also have the ability to adjust the angle of the
T foil while sailing.

Regards,
Phill

I know that the voices in my head aint real,
but they have some pretty good ideas.
There is no such thing as a quick fix and I've never had free lunch!