The scientists studied how sand moves along a beach with waves and currents. They used traps to measure the sand in the water and created a model to estimate how much sand moves along the shore. The model's predictions matched well with the actual data. Sometimes, the sand distribution had two peaks due to waves breaking over underwater bars. Comparing their results with existing formulas, they found that sand transport in the surf zone is similar to other flow conditions. This study adds new information about how sand moves on a beach with waves and currents.