Low-lying countries, such as the Netherlands, are strongly dependent on good and safe sea defences. In the past, the design of dikes and revetments was mostly based on vague experience, rather than on general valid calculation methods. The demand for reliable design methods for protective structures has, in the Netherlands, resulted in increased research in this field. These contributions have been prepared by Dutch experts participating in the study groups of the Technical Advisory Committee on Water Defences. The book opens with an outline of general strategy and methodology on sea defences, illustrated in the following chapters by technical information on specific items and Dutch experience, and it ends with more general aspects such as probabilistic approach, integral (multifunctional) design, management & safety assessment. Together, these chapters provide an almost complete technical overview of the items needed for the design and maintenance of dikes and revetments. The enclosed CRESS-program allows for an initial estimation of hydraulic loads and preliminary design.