The sea is naturally clear then what ever colour the sky is the sea is. It is a reflection of the sky.
it gets little sunnlight
Waves, oceans, briny deep, drink, blue, expanse...
A Great White lives in the deep blue cold seas
The vampire squid is a deep sea detritivore.
to protect them from predatirs
In the galapos islands
Savage Seas - 1999 The Deep 1-3 was released on: USA: 1999
they are brilliant
"The Deep Blue Sea" is a film released in 2011. If the question is about the actual sea one would need to know which sea and since much of the world beneath the ocean is unknown it is difficult to determine just how long and wide the oceans and seas are.
seas are not really blue, the sky reflects on the sea thats why whan its a rainy day,the sea seems plain.
sees, seas
The oceans are often referred to as deep dark seas especially in literature.