When I bought my first cruising sailboat, I falsely assumed the rudder was watertight. I later learned otherwise when I began seeing rust streaks at the seams. The staff at my boatyard informed me that water can get into the rudder around the rudderstock where it meets the fiberglass. To reduce fiberglass delamination, internal rusting of the rudder’s armature and the possibility of blisters forming, they recommended I drill a small hole near the bottom of the rudder whenever I haul my boat for storage in the fall.
Now every year when I drill a hole in my rudder, I am amazed at the trickle of water that comes running out. I leave the hole open through the winter to allow the rudder to drain completely. In the spring before bottom painting I patch the hole with a little Marine-Tex.
Photo by Bill Bleyer