The purpose of this Bulletin is to document naval architectural practices and conventions used in the estimation and determination of the weight, centers of gravity and weight moments of inertia for surface ships, and to reference sources of weight estimating data for ships and their components for use at various stages of design. Conventions and practices for offshore drill rigs, high speed craft and submarines are mentioned in some instances to demonstrate alternative methodologies, but are documented only by references. Military practices and conventions are summarized and referenced but not fully documented.