Dinghy Rudder Change on Kite Dinghy

[BobBill]

So not to hijack a thread on rudder problem, wherein I failed to figure out ratios of rudder area to hull.

Two rudders here, one original barn door and Laser II kick-up rudder. One atop the other. The pic has the blades in about same operating position to each other.

I figure to add the fore/aft section to the Laser to come forward of the stern a bit, while going deeper or wider or a combination to achieve balance and so on where the barn door's lateral planes extend.

I understand the dynamics of the forward edge, but wonder if I really need to match surface for surface. I was going to hang it and try it, but seems the surface differences hints the results.

This is more an experiment to gain kick-up without destroying original rudder, Old rudder is sound.

[gggGuest]

I'd just put it on there mate: plenty of classes have far bigger variations of rudder shape and size without it making any important difference to the balance or handling.