Had a similar problem with the rudder on my 34-2. There was a bulge in one side and the trailing edge had separated. After draining the water I dropped the rudder, cut out the bulge and let the rudder dry out over the winter in my basement.
Once the rudder was dry I filled the cut out area with epoxy thickened with micro balloons and re skinned the rudder with a layer of 1708 cloth. At he point where the post enters the rudder I used a dremel tool to cut a groove around the post and fitted the post with an O ring and sealed it with 5200.
Its been four years since I did the repair and am happy to report that the rudder is still bone dry.