Colours Underwater and why they change

Many people don’t realise the effect that depth has on colours underwater. DJL instructor Dani explains why the brightness of colours decreases the deeper you dive.

colours underwater

Colours underwater

“So, one of the first things a new scuba diver may notice is the surprising lack of color, it may not be apparent on the first few dives as they are focusing on everything else around them. However the more you dive the more you notice the distinct lack of colour underwater the deeper you go.

You may be thinking about all the national geographic videos or PADI magazines that make everything look so bright underwater. Don’t worry they aren’t ripping you off! The brightness is there, but it may need some light to help bring it back!

Why this happens

The fact is, water absorbs light rapidly. So rapidly, that after only 300 ft (80 m), no visible light remains. Only experienced technical divers will descend to this sort of depth, but it is still importan to note that absorption still occurs.

There are familiar constituent colours which the visible light spectrum can be broken up into. From least to highest energy, red, orange, yellow, green, blue, and violet. This order is important, because it is the lowest energy colors that the water absorbs first. This chart below shows the depths at which water absorbs different colors. These are approximate, as water clarity and turbidity affect colour absorption.

colours underwater

What is doing the absorbing exactly? All water contains microscopic particles. Light strikes these particles and scatters, with some of the light absorbed. What remains is what colour you see. The further that light travels the more colours become absorbed until there is only blue light remaining. This also eventually becomes absorbed. So there you have it, red light absorbed more rapidly due to its higher energy properties whereas blue light has a lower energy property so is absorbed last!

To illustrate, I’ve recreated how some common items would look at different depths.

colours underwatercolours underwater

 

 

 

 

 

Notice on the Sprite can  how the red is removed from the orange, leaving a little color while the blue text is unaffected.

You can however help see things a little brighter underwater by purchasing a mask with a red filter, for example the spectra truefit, or by adding a red filter to your cameras to help bring some brightness to your photos.

Happy diving guys 🙂 Stay bright!”

Dani

Add Comment