Epipelagic

Sunlight zone

Enough light for photosynthesis. Almost every fish you can name lives in this thin band.

0m

Below surface

Pressure

1atm

Temperature

22.0°C

Surface light

Flooding ballast

Reached

10,994 metres. The bottom of the world.

More people have been to the Moon than to the Challenger Deep. Every depth on the way down is real — the Titanic really is at 3,800 m, and a sperm whale really does hunt at 1,200 m on a single breath.