Rudder Vibes
Pat, I'll assume that the rudder groans or vibrates at speed. It would also help to know what kind a boat you have. Rudder vibes can be caused by turbulence created by the squared off trailing edge of the rudder. In theory, the rudder trailing edge should be a knife edge. Structual concerns dictate that the trailing edge be 1/4" to 1/8" thick. Racing sailors have discovered that shaping the trailing edges of underwater foils into a chisel shape will eliminate most of the vibration. A small angle on the trailing edge will suffice. Rodney Kidd C-38 #297, Flying Bear
