[willy]

I don't think that is your boat, and a cored hull is when there is an inside laminate (fiberglass) and an outside laminate(fiberglass) and in between the two is another material, usually some type of foam (hard).
It is the way some boats are manufactured, some are cored only above the water line. Some, like certain year Luhr's were even cored below the water line. As we used to say when I was stationed in Vicenza "no f*ckin buono" below the water line.
The lines of your boat are very similar to the Scarab hull from Wellcraft, the big difference is the stern. But manufacturers used to put a plug in their molds in the rear to change the stern or to shorten the length of the hull.
The big issue for me is the front of your boat, looking at it from the front looks very much like the older Formula 233.