I had the same issue with my 77 OD25 causing a catastrophic failure while sailing. The chainplate pulled through the bulkhead and shot thru the deck causing the mast to go overboard and snapping the roller furler. Not a fun day...spent the summer replacing the bulkheads....just got her back in the water. My advice is don't sail her until you fix the issue. See my recent threads for info about the repair.I've recently discovered dry rot in my bulkhead, it is an oday 25, any suggestions on how to repair or replace?