I don't own a Wildcat, but all F18's have some type of inward angle built into the tiller portion of the rudder to provide ackermann steering geometry. This creates a left and right rudder assembly. I'd guess most if not all other aspects of the rudder should be symmetrical.
With regard to ackermann, in simple terms, during a turn, the rudder on the inside of the turn is at a sharper angle than the one on outside of the turn. The benefit on a catamaran is to reduce drag during the turn.
https://en.wikipedia.org/wiki/Ackermann ... g_geometry