Provides step-by-step guidance on the stages of designing both power and sailing boats, whilst also explaining the reasons behind the process. Line diagrams and reproductions of working drawings are used to help understanding and demonstrate the typical plans from a wide range of vessels. The usual calculations employed in all boat design work, requiring only very basic arithmetical skills, are set out and typical examples worked through. In addition, speed / power tables are given for motor boats as well as a method for checking balance under sail.