We fasten carbon and/or aluminum beams down to the hull mouldings using bolts tapped into inserts in the hull with the bolts fitting inside "compression" loaders through the beams similar to the way that Marstom fit their carbon beams to their carbon hulls, (I think you will find that this is the normal practice and not the exception) The Australian "Flyer" uses the same system with carbon. (I don't relly understand why the question??)