Why does water in deep-sea seem to be bluish?

Sea has many tiny particles to scatter light. The sunlight is made up of seven colours, most of the longer wavelength lights (red, orange, yellow etc.) present in it do not get scattered much and hence pass straight through. The shorter wavelength blue light is however scattered all around.The scattering of the blue component of the white sunlight by tiny molecules causes the blue colour of the sea.


9