Have an interesting fact taken from my Frozen Planet course for you followers!
That age old question, why is the sea blue?
Or the more accurate question is, why does the sea APPEAR blue?
This is due to light. Natural night is made up of several different colours, like you see in a rainbow. When the light hits the sea surface, the light at the end of red part of the spectrum is absorbed more than the blue. As a result, the deeper down you go into the sea, the more absence of red light. Blue light is not absorbed so much by the sea. This is why the sea appears blue!
Simple as that! :)

Have an interesting fact taken from my Frozen Planet course for you followers!

That age old question, why is the sea blue?

Or the more accurate question is, why does the sea APPEAR blue?

This is due to light. Natural night is made up of several different colours, like you see in a rainbow. When the light hits the sea surface, the light at the end of red part of the spectrum is absorbed more than the blue. As a result, the deeper down you go into the sea, the more absence of red light. Blue light is not absorbed so much by the sea. This is why the sea appears blue!

Simple as that! :)