Deck plates
Sounds like the cover on the deck plate is tired and needs to be replaced. Beckson (beckson.com) makes them as well as others. West, Defender, etc. should all have them. Water leaking through the cover down to the rudder post shouldn't be a big problem. It'll get to the steering quadrant and then leak into the bilge or continue on down into the ocean. If the frame around the cover is shot then it could well leak water into the core of the deck as the deck was most likely not sealed at that point and that can be big trouble. I'd remove the screws from the deck plate flange and pull it (or break it) out. Dig out any wet core, clean and dry the whole thing and fill in the void with epoxy filler to seal the deck core. Then install a new deck plate. The joys of owning a used boat!!
