I have recently inspected a HUNTER 410 (2000 model) and have noted a slight damage on the trailing edge of the vertical keel plate. This appears to be a detachment between the lower and upper parts of the keel. No other structural damage was noted in the area. A photo is attached. Any ideas how this keel is built up and what the damage may signify ? My first reaction is that it is caused by impact damage when going astern, but cannot confirm this. The keel bolts are intact and tight and no water anywhere inside. The boat is in overall very good condition. A sketch of the construction of this keel would be useful to advise a repair solution.