Ship design is a complex iterative procedure and is comprised of several phases during which the design is developed in increasing degrees of details. Now a day, it seems that with the aid of modern technologies, ship design has become easier and convenient for the Naval Architects (N A) . However, expertise knowledge of various design software can not alone ensure a high degree of proficiency in ship design process. To become an expert designer it is very important for a N A to know the basic logic, theories, hypotheses, thumb rules of ship design based on which the software are developed. A clear understanding of these background knowledge will help the designer to operate and modify the software more effectively. Based on these ideas, the aim of this book is to provide a complete, fundamental understanding of the ship design procedure through the systematic explanation of each major step of an oil tanker design . This chronological description of the entire preliminary design phase should be especially useful to young naval architects (or any ship designer who comes from a different expertise field) to build up an insight understanding of the entire process of ship design.