I don't have a valid opinion on the size of the rudders on the catamaran since the only cat I've ever sailed is a Hobie 16. Looking at the picture in colmj's earlier post I think the shafts look puny. Coupled with the fact that Doan reported one rudder appearangly bent under what were sporty but otherwise sailable conditions tells me the shaft was too small. There is another photo in this string showing the repair they attempted with the free-wheeling rudder using an allen wrench to replace the missing or sheared pin. I've spend a working career around all sorts of equipment where we mount levers on shafts for everything from huge combustion control air dampers to log and panel turners. If one of my designers came to me with that method of mounting and keying I would give him one more chance before sending him down the road. A pin instead of a key is a horrible method for high torque situations. Unless the pin and shaft are set for what we call an "Interference Fit" it will not hold solid and will eventually fail. I expect there was some rotation between the rudder and shaft from the very beginning. An interference fit is obtained by either chilling the pin with dry ice and driving it in place (quickly, mind you) or being drawn in from a slightly smaller diameter guide section. The application for the pinned joint would be rare and only done for some special circumstance. The whole arrangement of the rudder shaft mount looks like it was designed primarily from a cost standpoint. The builder saved a few bucks so the new owner could lose his pride and joy on the maiden voyage. Luckily nobody was hurt or killed. Based on the reports, both rudders failed under what appear to be 2 different modes. In my humble opinion (like I ever had a humble one ;o) the builder should be liable for the loss.