About a year after purchasing our 380, we had “dribbles” from the V-berth hatch, when raining.  I fooled around with this for multiple times, silicon greased the seal, no fix, etc.  It ended up that the problem was at one of the two hinge mounts.  There is one or two screws there that hold the top and bottom together, pinching the lens in between.  I put some silicone sealant on the top side, and ran sealant into the screw holes.  Problem fixed and has stayed fixed for the past 18 months.  You might try to isolate your leak, if possible.  Since ours was dripping at the hinge, that sort of got me pointed in the right direction.

Dr. Sam Balsley
Barca a Vela, C380, #322
Sausalito, CA