I had a cunning thought the other day... I reckon I can fit a 3mm stainless plate onto the rudder bracket in such a way that it sandwiches in and takes up the well known slop.
Now the cunning part of this is that they could remain fixed in the down position... so when the normal rudders are pulled up then the stumpies would stay in the water, going down not much mare than say 6" below the hull. Could give a real bonus when spinning around on engine only, and I don't think there's any danger at high speed either as they'd be well out of the way of the props Bernoulli current.
Pivot on the some bolt as the main rudder, maybe using the transit hole to lock it in place (Somehow cunningly.. can't quite see this ingenius contraption yet) while in use (another hole through main rudder not good as they won't kick up on grounding)
Perhaps the leading edge of the stumpy could do with a fold n weld to brace against flexing.
Would be curious to hear any thoughts on this.
Alternativly there is Masquerades approach, which is based on having a rudder blade fixed onto the engine. Pretty cunning too, but I forgot to ask how good it was, or maybe I just forgot the answer...