Re-glass it
Last spring, the skin on the rudder on my '89 H30 completely detached. At first, it looked like a thin crack down the leading edge, but when the crack was ground to prepare it for repair, the whole skin fell off. Since the foam core was in good condition, this was an easy repair. I hired a local fiberglass guy who re-glassed and gel coated the rudder without removing it from the boat. Boat was ready in time for spring launch. Price was very reasonable compared to replacing the rudder. It still looks good after fall haul out. I never did figure out if the delamination was caused by freezing or heating by the sun. But I'm going to cover the rudder this year before the weather starts to warm up. Many people advise this, especially with dark colored anti-fouling paint.
