INVISIBLE RESIDENTS, a USO Book written 55 years ago
COMPELLING EVIDENCE OF AN UNDERWATER CIVILISATION
Man is busily penetrating the space that lies around his planet, but what of the 75% of the earth that lies beneath water? Have we been ignoring a wealth of evidence that corroborates the existence of intelligent underwater life?
Lighted objects which appear from or disappear into rivers, lakes and seas . . .time—speed anomalies experienced by pilots over certain tracts of water. . .
the unexplained total disappearance of ships, air¬craft and crews in definite lozenge-shaped areas of the oceans - is this evidence that there may be under¬water 'civilisations' on this planet that (have evolved here? Or are there intelligent entities who have been coming here from elsewhere, preferring to use the bottom of the hydrosphere from which to operate? INVISIBLE RESIDENTS is a-startling book, which opens new frontiers to the speculative mind.
https://archive.org/details/invisible-residents-ivan-sanderson