the maximum breadth of the vessel, measured amidships to the moulded line of the frame in a vessel with a metal shell and to the outer surface of the hull in a vessel with a shell of any other material, the breadth over the frames of a ship, ie heel of frame to heel of frame. It is the breadth termed B by Lloyd's Register, and it is the line fairest in the moulding loft. Measured at the widest part of the hull.