A breaking wave can adopt one of three shapes: surging, overflowing, or plummeting. Raging waves This sort of wave surges up the beach rather than breaking as it comes in from relatively deep ocean. These waves are usually very large and may be either peak or trough waves. Surging waves are the most powerful but also the least consistent wave type. They tend to occur when there is a strong onshore wind or other force driving water onto an open beach. The wave will continue to surge even after it breaks because more waves are arriving to add their energy to the first one. The only time you will not see any more waves after a surging wave has retreated far enough back from the shore is if it was completely absorbed into the sand or another body of water. Overflowing waves As the name suggests, these waves rise over the top of the sea wall or cliff and then fall back down again. They can be quite large and have a wide variety of shapes depending on the underlying cause. Plunge pools are a common form of overflowing wave. They occur when there is heavy rain falling close to the coast, which washes away some of the soil under the surface of the water. This creates a pool of water that rushes towards the land with the help of the incoming tide. The wave reaches the edge of the cliff or sea wall and then falls back down the far side, creating a splash as it goes over the top.