This wave energy is generated by the frictional effect of winds moving over the ocean surface. The higher the wind speed and the longer the fetch , or distance of open water across which the wind blows and waves travel, the larger the waves and the more energy they therefore possess. It is important to realize that moving waves do not move the water itself forward, but rather the waves impart a circular motion to the individual molecules of water. If you have ever gone fishing in a boat on the ocean or a large lake you will have experienced this phenomenon. As a moving wave passes beneath you, the boat rises and falls but does not move any distance across the water body.
Waves posses several measurable characteristics including length and height.
Wavelength is defined as the horizontal distance from wave crest to wave crest, while wave height is the vertical difference between the wave's trough and crest . The time taken for successive crests to pass a point is called the wave period and remains almost constant despite other changes in the wave. They also have longer wave periods and this is how they are distinguished from the short sea waves on reaching the coast. Long swells which have traveled hundreds of kilometres may have wave periods of up to 20 seconds. Smaller sea waves have wave periods of 5 to 8 seconds.