In the Ariel the heel was molded as part of the hull and foam was subsequently poured into the back of the hull to fill this deep narrow area. It was then glassed over to prevent water from getting at the foam and to allow for easier cleaning. If you think there is water down in the back of the keel, I would drill a hole at the bottom below the foamed area, drain it, reseal it, and then
redo the glass job on the interior over the foam.
Mike,
This is hull #24, maybe the whole glassing over the foam idea wasn't part of the process yet. Drilling is certainly in my future with the possibility of a garboard type plug to drain at haulout each year. The plug I think is a prudent idea seeing how the temps around here can get pretty low.