Rip currents play a big role in moving water and stuff like sand and pollution between the beach and the ocean. Scientists studied how waves and currents work on a beach with two sandbars. They found that when big waves break far out, it makes a swirling current in the water near the shore. This current can trap things in the water, making it hard for them to get out to sea. But when waves are smaller, things can flow out more easily. So, the size of the waves affects how stuff moves in the water near the beach.