Secchi Disk

A Secchi Disk is a simple tool used to measure water clarity or transparency in lakes, rivers, and oceans. It is a black-and-white patterned disk attached to a rope or line. To use it, the observer lowers the disk into the water until it can no longer be seen, then records that depth. Removing the disk slightly and noting the depth again gives an estimate of how clear the water is. Clearer water allows the disk to be seen at greater depths, indicating lower levels of suspended particles and algae. It's a straightforward way to monitor water quality and aquatic health.