I have brown water stains coming from the horizontal hull liner joint below the windows on the starboard side. The stanchions, windows, and deck hardware do not seem to be leaking. I wonder if the mast plate is the problem. Mast support post is solid no rot. But I wonder if the mast plate is leaking and the water is running down the wiring. Is there a wooden cross support between the plate and the post? Does the 240 have a wood core in the deck? Does any one have experience with this?