This is the fourth Volume of the six Volume Open University set. Each Volume is used by students as a relevant part of the Open University course in the UK, but designed so that it can equally be used as an individual text book. This Volume describes waves, their measurement and characteristics, their behaviour in shallow water and unusual waves. It also considers mainly theoretical aspects of sediment movement and deposition of currents, wave estuaries, and the interaction of waves, tides and river flow in deltas. Concludes with a look at shelf-sea processes and their mineral resources. Each Volume in this set is well laid out and copiously illustrated with full colour photographs, graphs and graphics. Questions to help develop arguments and/or understanding can be found in the text and at the end of each chapter, with worked answers provided at the back of each Volume. Each chapter also concludes with a summary to help consolidate understanding before the next chapter is begun.