Blue whale

Balaenoptera musculus, 0 to 500 m

The largest animal that has ever lived, feeding on some of the smallest.

Great white shark

Carcharodon carcharias, 0 to 1,200 m

Tagged individuals drop far past this zone, into water they have no obvious reason to visit.

Portuguese man o' war

Physalia physalis, 0 to 0 m

Not one animal. A colony of four kinds of organism that cannot survive apart.

Recreational scuba

40 m

The agreed limit for a certified recreational diver.

Vampire squid

Vampyroteuthis infernalis, 600 to 900 m

Neither a vampire nor a squid. It eats marine snow, and turns itself inside out when frightened.

Lanternfish

Myctophidae, 200 to 1,000 m

Possibly the most abundant vertebrate on the planet. You have almost certainly never seen one.

Giant squid

Architeuthis dux, 300 to 1,000 m

Never filmed alive until 2012. Its eyes reach about 27 cm across, matched only by the colossal squid.

Ahmed Gabr

332 m, 2014, Egypt

Deepest scuba dive on record. Down in 15 minutes, back up over 13 hours 35.

Nuclear submarine

500 m

Crush depths are classified. Operating depth is believed to be a few hundred metres.

Anglerfish

Ceratiidae, 300 to 4,000 m

The male is a fraction of the size of the female, bites on, and fuses to her permanently, losing his eyes and most of his organs.

Sperm whale

Physeter macrocephalus, 0 to 2,250 m

Hunts giant squid in total darkness using sound alone. The scars on their heads are from squid that fought back.

Colossal squid

Mesonychoteuthis hamiltoni, 100 to 2,000 m

The heaviest invertebrate known: one weighed 495 kg. First filmed alive in its own habitat in March 2025, a 30 cm juvenile at 600 m.

Gulper eel

Eurypharynx pelecanoides, 500 to 3,000 m

A mouth with a fish attached. It can swallow prey larger than itself.

Cuvier's beaked whale

2,992 m, 2014

Not a vessel. The deepest dive ever recorded by any mammal, and it ends here, in the dark.

Dumbo octopus

Grimpoteuthis, 3,000 to 6,957 m

Filmed at 6,957 m in the Java Trench in 2020, the first hard proof of a cephalopod living in the hadal zone.

Tripod fish

Bathypterois grallator, 800 to 4,720 m

Stands on three stiffened fins on the seabed, faces the current, and waits. It may be functionally blind.

Sea pig

Scotoplanes, 1,000 to 6,000 m

A sea cucumber that walks across the abyssal plain on inflatable legs, in herds.

DSV Nautile

6,000 m, 1984, France

Recovered thousands of artefacts from the Titanic.

Hadal snailfish

Pseudoliparis, 6,000 to 8,336 m

Filmed at 8,336 m in the Izu-Ogasawara Trench in 2022, the deepest fish ever recorded and close to the limit for any fish.

Amphipod

Hirondellea gigas, 6,000 to 10,935 m

Swarms the very bottom of the Challenger Deep. Digests wood with an enzyme found nowhere else.

Xenophyophore

Xenophyophorea, 500 to 10,641 m

A single-celled organism up to 20 cm across. One cell, the size of your hand.

DSV Alvin

6,500 m, 1964, USA

Surveyed the Titanic wreck in 1986. Re-certified in 2021 for 6,500 m, which reaches 99% of the seafloor.

DSV Shinkai 6500

6,500 m, 1989, Japan

Still one of the deepest-diving crewed research submersibles in service.

DSV Jiaolong

7,062 m, 2010, China

Reached 7,062 m in the Mariana Trench in 2012.

Deepsea Challenger

10,908 m, 2012, USA

James Cameron, alone, the first crewed return to the bottom in 52 years.

Fendouzhe

10,909 m, 2020, China

Chinese national record, 10 November 2020. Thirteen dives, eight of them past 10,000 m.

Bathyscaphe Trieste

10,911 m, 1960, Switzerland / USA

Piccard and Walsh, 23 January 1960. A window cracked on the way down. They stayed twenty minutes.

DSV Limiting Factor

10,925 m, 2019, USA

The first submersible able to make the trip repeatedly. Its 2020 transects set the depth figure still in use.

Sardines

Schooling fish, surface waters

Under attack, a school packs into a tight spinning bait ball, so no single fish is easy to pick out.

Jellyfish

Cnidaria, surface to trench

No brain, no heart, no bones, and drifting through the oceans for more than 500 million years.

Siphonophore

Siphonophorae, twilight and midnight zones

Not one animal but a colony of clones, each doing one job. Some grow longer than a blue whale.