Why Underwater Visibility Decreases with Depth

Light attenuates rapidly underwater due to four combined factors:

1. Water absorption: Water molecules absorb red/orange wavelengths first; blue/green penetrate deepest.
2. Scattering: Molecules scatter shorter (blue) wavelengths more, creating the blue-green cast.
3. Dissolved Organic Matter (DOM): Decaying material absorbs visible light.
4. Particles & Plankton: Suspended sediments and organisms scatter and absorb light.

Result: darkness increases exponentially; artificial lights are essential for deep exploration.