Jake and I cracked one at the Tradewinds on the DLW in 2004. we sailed in, cut 2 inches off and sailed the rest of the regatta. My 5.2 had multiple cracked arms, and Ive seen a few more on various NACRA's, but mostly it comes from abuse of the crossbar(falling on it, pushing on it.etc...) easy fix with a few rivets and some new aluminum. Jake and I also broke the adjustment screw eye on the rudder casting on day 1 of the 2004 Tybee. Apprently that 1/4 inch steel screw can suffer some pressure. Good thing it was on the starboard rudder, as we were able to remove the whole rudder and I steered with the crossbar which was loose on the starboard side. No trapezing that day, but we still made good time. My advise if youre gonna do this type of race...check EVERYTHING, replace what you can afford to, and bring extras of everything else. we even had a pocket sewn into the tramp for extra rudder, but since that wasnt what broke, it didnt help us.