Giant squid
300–1,000 m
Up to 13 metres long, with the largest eyes of any animal on Earth.
A dive in five zones
The Deep
From the bright surface to the bottom of the Mariana Trench: 10,935 metres of water, pressure and strange light.
The ocean covers 71% of our planet and most of it is dark. Breathe in, and follow the light down.
Sunlight zone
0–200 m
0 °C
- Photosynthesis happens here, feeding almost every ocean food chain.
- Whale sharks, the largest fish alive, cruise these waters filter-feeding on plankton.
- Over 90% of all marine life lives in this thin, bright skin of the sea.
Twilight zone
200–1,000 m
0 °C
- Light fades to almost nothing by 1,000 m, yet animals still make daily vertical migrations.
- Many jellyfish and squid make their own light to confuse predators.
- Every night, billions of fish rise to feed near the surface and sink back at dawn.
Midnight zone
1,000–4,000 m
0 °C
- No sunlight has ever reached this depth; about three quarters of animals here make light.
- Anglerfish dangle a glowing lure to draw prey into reach in total darkness.
- Sperm whales dive this deep to hunt giant squid.
Abyss
4,000–6,000 m
0 °C
- Water here is just above freezing and the pressure exceeds 600 times that at the surface.
- Sea cucumbers graze the ooze, recycling the slow rain of dead plankton called marine snow.
- Cold-water corals grow on rocky ridges, some for thousands of years.
Hadal zone
6,000–10,935 m
0 °C
- Named for Hades, this zone exists only in trenches, deeper than Everest is tall.
- Translucent amphipods thrive here, even eating through the plastic that has now reached the bottom.
- At Challenger Deep, the pressure is about eight tonnes per square inch.
Creatures of every depth
Vampire squid
600–1,200 m
Lives in the oxygen-poor midwater and sheds glowing mucus to escape predators.
Dumbo octopus
3,000–4,000 m
Flaps ear-like fins to hover above the seabed. Some have been filmed beyond 7,000 m.
Deep-sea jellyfish
200–4,000 m
Many species glow, flashing blue light to startle attackers or call for help.
Gulper eel
500–3,000 m
A hinged, balloon-like mouth lets it swallow prey bigger than its own body.
Anglerfish
1,000–4,000 m
Females carry a glowing lure; the tiny males fuse to them for life.
We know more about the surface of the Moon than the floor of our own ocean, yet every second breath we take comes from the sea.
Challenger Deep, 10,935 m
Protect the deep
You have reached the bottom. Now help keep it wild: a pledge is a promise to choose less plastic, back protected waters and share what you saw.
18,412 of 25,000 pledges
Cut single-use plastic
Swap bottles, bags and wipes. Plastic has been found in the Mariana Trench.
Back marine protection
Support high-seas treaty campaigns and 30% ocean protection by 2030.
Fund a dive for a classroom
£12 puts one school class through our Deep Ocean workshop.