Hydraulics is the study of fluids whether in motion or at rest. Hydrodynamics is the study of fluids in motion, and hydrostatics considers the properties of fluids in static equilibrium. In physics and engineering, fluid dynamics is a subdiscipline of fluid mechanics that describes the flow of fluids-liquids and gases. It has several subdisciplines, including aerodynamics (the study of air and other gases in motion) and hydrodynamics.
Oceans cover 71% of Earth’s surface and contain 97% of Earth’s water. Largest ocean is the Pacific ocean and covers about 30% of Earth’s surface. In order to explore and exploit the resources, a knowledge on the ocean environment is essential. To have a knowledge on the physics of waves ,tides and currents, the subject of wave hydrodynamics will be important.