Although it is ideal that lines is decided theoretically to satisfy the requirements and to have the best performances, it is impossible. Accordingly we applied an electronic computer to make the offset of a new ship based on a practical method, doing necessary corrections against the offset of the type ship. On the other hand, as the method contains some points having no generality, we analized the points and tried to express them by the mathematical formulae. The corrections are as follows, (a) The offset of the type ship to be corrected to coincide with principal dimensions, figure of midship section and profile of the new ship, because those of the new ship to be individual to those of the type ship. (b) The offset corrected at (a) step, to be adjusted to coincide with the prismatic curve of the new ship, and the displacement and location of center of buoyancy so as to equal to required values.
