The Caribbean basin has other areas like this
Off the coast of the Bahamas, in the 1970's or early 80's there was a big report about underwater cities and structures.
They were geological, not anthropological.
These willbe too, I am nearly certain.
Castro is pushing this because it gives him attention that is positive, and diverts attention from his tyranny.
He is like other despots who have pet "science" projects. Rememebr Lysenko?
Ed