New Rudder above, Old Rudder below
I put the Hobie Adventure Island Sailing rudder on my Cobra Expedition. This is the boat's fourth rudder. Two were the standard rudder that Cobra provides. Both of those broke in the surf so I made my own from a piece of plastic cutting board. This flat plate rudder was very strong but I could hear it gurgle every time I pushed it into a hard turn. When you hear a flat plate rudder gurgling it is acting more as a brake than as a rudder. The Hobie Sailing Rudder has a nice foiled shape, so it should not stall as easily. I may not turn better, but at least it will slow me down as much.
In years gone by, I got an expensive foiled rudder for my Hunter 235 sailboat in a size for a 26 foot Hunter. It made the boat turn much better, and also allowed me to sail closer to the wind. At first the local racing authority let it slide. The thought was, a bigger rudder would be more drag and a disadvantage. Over time they realized it did give me an advantage and adjusted my rating a bit.
I hope to have the same experience with this rudder upgrade.