GS44MC Cored Hull?

[GMB]

Has anyone cut through-hull openings on a Gulfstar 44MC? If so, where on the hull and what materials and thicknesses did you find? I'm looking at a survey for a 1980 44MC model and in regard to hull material is says:

"...fully balsa cored molded fiberglass gelcoat cosmetic finish"

I suspect the keel area must be solid FRP but would like to hear from those with first hand knowledge.

[boatpoker]

The keel is solid glass but chopped mat and very thin, I've seen two keels crushed due to inadequate blocking. The blocks MUST be wider than the keel and a minimum of four.