Waves are created by wind blowing across the ocean surface, transferring energy to the water. The stronger and longer the wind blows, the larger the waves become.

Ocean waves travel in groups called wave trains, moving across vast distances while the water itself moves very little. A wave's height, length, and speed depend on wind speed, duration, and the distance over which it blows.

The deepest ocean trenches can reach depths of over 36,000 feet, yet waves at the surface are driven by winds in the atmosphere above. Waves can travel thousands of miles across open ocean before reaching shore.

When waves approach shallow water near the coast, friction with the seafloor slows the wave base while the top continues forward, causing the wave to rise and eventually break. This is what creates the crashing waves we see on beaches.