How do waves form and break?

Wind is responsible for waves. As wind rushes up along the water, the friction causes ripples. Wind continues to push against these ripples in a snowball effect that eventually creates a large wave. Essentially, this action is a transfer of energy from the sun to the wind to the waves. As a swell approaches the coastline and comes into contact with the sea floor the waves will start to slow down. Some of the waves' energy is lost through contact with the sea floor. The shallower the water becomes the slower they move. As they slow down they have to squash together. This process is called shoaling and results in increasing wave height. The steeper the sea floor gradient the more pronounced the wave height will increase. The increase in wave height begins to occur at depths of around one half of the wavelength.