How does a wave break on a beach?

There are two main factors that affect the break of a certain wave. They are -

1. The depth of the wave where it is breaking. Every waves breaks on a spot of the sand where the depth (the bottom of the wave to the sand) of the wave is half as deep as the wave is tall. For example.: if the wave is depth is 1 meter deep, then the height of the wave will be 2 metres.

2. The speed of the wave. If the wave is travelling at a high speed, then the barrel of the wave will shape like a lying-down almond. Reduce the speed of the wave and the barrel will be shaped like a circle. Decrease the speed even more, and you will observe that the barrel is more like a standing-up almond. Lessen the speed even more and the foam (white, rough part of the wave) will slide down the face of the wave. This is the slowest breaking wave form you can get.

Waves come in sets, which are effected by gravitational forces which are controlled by the moon. Each set includes roughly 6-8 waves, with the waves getting bigger throughout the set.

Unbroken waves, which usually occur in high tide, is where the wave is too small to break, forcing it to remain unbroken. But there are some beaches where no waves. This is probably because the bottom is too shallow, the beach doesn't get affected by the moon, or there are large rocks underneath the water, causing the surface water to remain calm.

Yet, tsunamis and rogue waves are a totally different story. They are usually triggered by underwater earthquakes or volcanoes, or even small meteorites.