Thanks again Bill your experiences are helping me make some choices.

After doing some research, I am seriously considering coating the rudder with CPES until it refuses to accept anymore, then creating a barrier coat on top of that with a thin coat of West System Epoxy. This should prevent (or at least slow down) water intrusion and stiffen the rudder a little. Structurally it might not make that much difference as it will only be resins no glass. I am going to remove the rudder this week so that I can take it indoors where it will dry out better. I have a little while before the temperatures reach epoxy heights so I'll sit on it a while longer and do more research.