The primary purpose of writing this book is to support the learners and is prepared for case study projects. This book deals with the analytical formulation and finite element analysis of stiffened cylindrical hulls (different stiffener shapes) for minimizing the buckling pressure. The numerical design of isotropic hull is critical for submersibles such as Autonomous Underwater Vehicles (AUV), Remotely Operated Vehicles (ROV), submarines etc. Offshore drilling rings have led to an increasing demand for optimized structural design of pressure hull in Naval applications. An analytical model was developed for the prediction of the minimum buckling load with stiffened cylindrical hulls. The advent of this book is to prepare the analytical model of pressure hull along with stiffeners (both ring and T ) to withstand the buckling pressures and to reduce the failure. This book is evident from analytical and numerical methods that both the formulations are in close agreement with each other.