The ocean looks blue because of how it absorbs sunlight.
Water absorbs the longer wavelength colours at the red end of the light spectrum and the short wavelength violet and ultraviolet light.
Blue light is absorbed the least and is scattered and reflected back into our eyes, which makes the ocean look blue.
The actual shade of blue of the ocean depends several factors:
- Depth of the water.
- Amount of sunlight.
- What’s in the water. For example, if there’s a lot of green plant life the ocean can look more green.
Find out more about the amazing properties of water with our fun collection of water science experiments.