A current meter is a device used to measure the flow of water in rivers, lakes, and oceans. It typically consists of a rotating element, like a propeller or turbine, that spins as water flows past it. The speed of the rotation is directly related to the velocity of the water, allowing for accurate measurements of current flow. Current meters are essential tools in fields such as hydrology and oceanography, helping scientists understand water movement and its effects on ecosystems. They can be deployed in various environments, from small streams to large bodies of water, providing valuable data for research and environmental monitoring.