What is the Blue World?

I don't think Night even tries to hide the fact that it is Atlantis, and his dialog up front is not only a dead give away [ie same as song] but same message.  Here is the Donovan song from 1968, the most memorable line being his pronunciation of "Though Gods they weer".

Of course the mystical Story is the "she" where Donovan wants to be

The continent of Atlantis was an island
Which lay before the great flood
In the area we now call the Atlantic Ocean

So great an area of land that from her western shores
Those beautiful sailors journeyed to the South
And the North Americas with ease
In their ships with painted sails

To the East, Africa was a neighbor
Across a short strait of sea miles
The great Egyptian age is but a remnant of the Atlantian culture
The antediluvian kings colonized the world
All the Gods who play in the mythological dramas
In all legends from all lands were from fair Atlantis

Knowing her fate, Atlantis sent out ships
To all corners of the Earth, on board were the
Twelve, 'The poet, the physician, the farmer, the scientist
The magician and the other so-called Gods of our legends'

Though Gods they were
And as the elders of our time choose to remain blind
Let us rejoice and let us sing
And dance and ring in the new
Hail Atlantis

Way down below the ocean where I wanna be, she may be
Way down below the ocean where I wanna be, she may be
Way down below the ocean where I wanna be, she may be