Ninety-five percent of the ocean has never been seen by human eyes. Hold your breath. We're going down.
We have better maps of Mars than of our own sea floor. Below a thousand metres, no sunlight survives, the pressure would crush a submarine, and life makes its own light.
Where light still reaches, plankton turn sunshine into half the oxygen you breathe. Everything below depends on what falls from here.
A blue dusk that never ends. Every night, billions of animals rise to feed and sink again by dawn: the largest migration on the planet.
Total darkness. Light here is a language: lures, warnings, invisibility cloaks and love letters written in blue.
Near-freezing, crushing and silent. Vast plains of soft ooze where a single fallen whale feeds a community for fifty years.
Named for Hades. The Challenger Deep: more people have walked on the Moon than have been here.