Ask A Scientist General Science Archive

Question:  Why is the ocean blue?
 dawn m roach

Answer 1:
In effect, the ocean is not blue.  The water simply reflects the color
of the sky overhead (which appears to us as blue -- due to refraction
of incoming light).  Of course, ocean water contains much particulate
matter, but this does not cause the "blue" color.

Hope this helps!
 wildman jackson

Answer 2:
Actually, all colors of light enter the water and the yellow and red 
light is absorbed in the upper part of the water and only the green 
and blue spectrum of light remains to be seen by the eye. The ocean 
is blue because it does not contain particulate matter to change it 
to another color.  Coastal oceans are grren because of the microalgae 
(phyto-plankton) and because of organic conpunds like those that leak 
out of soil that are yellow.  If you dive under the water and look around,
you will seee that everything looks blue because no yellow or red light
can penetrate that deep and be reflected from objects and thus seen
by the eye.
Stacie