Secchi Disk

Real World Example

Imagine trying to read a book in a dimly lit room where the words become difficult to decipher due to the lack of light. Similarly, a Secchi disk is used to gauge how "lit" or clear water is, by measuring how far down into the water you can still see the disk before it disappears from view. Just like needing enough light to read a book clearly, the Secchi disk helps determine how "readable" or transparent the water is by assessing how deep light can penetrate, indicating water clarity or turbidity.