Understanding of the behavior of light underwater

Please register or login

Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.

Benefits of registering include

  • Ability to post and comment on topics and discussions.
  • A Free photo gallery to share your dive photos with the world.
  • You can make this box go away

Joining is quick and easy. Log in or Register now!


Reaction score
# of dives
I'm a Fish!
To know how the light propagates through water helps divers make informed lighting choices. Let’s view more info below.

*Behavior of light underwater
Light travels only relatively short distances through water, and the great part of the oceans is almost dark. When light propagates through water, its intensity decreases exponentially with distance from the source. The exponential loss of intensity is called attenuation and it is caused by absorption and scattering. Underwater visibility depends on contrast, which is a function partly of object brightness or reflectivity and partly of attenuation with distance.

Besides, direct illumination losses are primarily caused by the absorption of light in the water volume between the source and subject. Absorption of light in pure water is generally dominated by the interaction of photons with water molecules. As a photon contacts a water molecule, it’s absorbed and converted to heat energy. This interaction has a strong dependence on wavelength, with light in the red and violet ends of the spectrum being strongly attenuated while blue-green region of the visible spectrum has minimal attenuation. This is why seawater appears blue.

*Advantages of choosing LEDs for underwater lighting
Understanding how to evaluate a light for the mission requirements and how lighting parameters change underwater is important. With lighting technology developing, LEDs prove to be highly efficient and extremely flexible solutions, comparing with incandescent, fluorescent, HMI, and HID lighting. They are well suited to nearly every lighting application, also including underwater lighting.

Using LEDs, manufacturers can optimize dive lights with particular lighting characteristics requirements, such as, CCT, lumens, lux, CRI, color, and beam patterns. For example, to take u/w photography and video, many photographers choose some high output dive lights with multiple lighting modes for color compensation, create more vivid images...

Top Bottom