Numerous works of science fiction have been inspired by the concept of an underwater planet, but according to one team of experts, it's not too distant from reality.
They've found a region underneath the earth's surface that may contain several times more water than the rest of the planet's seas put together.
The finding, which may support a notion that challenges accepted beliefs about how water first entered the planet, was sparked by the discovery of a diamond.
Geoscientists from Goethe University in Frankfurt, Germany, were looking into a diamond that was discovered more than 2,100 feet below the surface of the earth in Botswana, Africa.
They discovered the stone had a lot of water inside of it after carefully examining its contents.
The diamond's high water content provides evidence in favor of the hitherto unproven idea that a vast ocean is suspended between the top and lower layers of the planet's crust.