I have a question regarding the mast crutch mounting hardware on a `94 23.5. Where the mast crutch bottom meets the lip of the hull/deck seam at the back of the boat is a circular foot that the crutch sits over. Directly beneath this is a hole on the bottom of the hull that can be seen when looking up at the bottom of the boat. Through this hole you can see a nut which I assume holds this circular foot for the mast crutch. Does anyone know, should there be a sealed plug (or cover) on this hole ? thanks