Check the "windshield refinishing" and the threads, they all leak sooner or later, and silicone is the worst thing to use. Instead I only use Sikaflex, and clean-up with acetone.
Watch out if you intend to take it apart for rebedding, I did the whole job on my 31 Commander Express, because it leaked like a sieve. And if you have a flybridge, do not forget the windshield holds the front of the bridge.