I would look at the drain bail plug first. If loose, remove the base and then reinsert with 5200 caulking making sure you lightly scratch that surface. Also make sure the plug is tight first.
It has been a while so the only other areas are the rudder attachement and where the centerboard comes thru the hull. check for loose screws first.
Is water being detected after in the water for sailing or simply sitting on the trailer. The reason for this is to make sure if coming in from topsides or under the hull.
crazy dave condon