Which whale is the deepest-diving marine mammal?

Cuvier's beaked whale is the deepest-diving marine mammal.

Cuvier’s beaked whales have been recorded descending to about 2,992 metres and remaining underwater for more than two hours. These records make the species the deepest-diving mammal known to science. It is a medium-sized toothed whale that lives in deep waters across much of the world’s oceans.

Its body is highly adapted for pressure and prolonged dives. The whale stores oxygen efficiently, slows its heart rate and reduces blood flow to less essential tissues while hunting squid and deep-sea fish. Its short beak and small, curved mouth give the species a distinctive profile.

Sperm whales are famous deep divers and can also exceed 2,000 metres, but the deepest confirmed mammalian dives belong to Cuvier’s beaked whale. Researchers use satellite tags and sound recordings to study an animal that is rarely seen at the surface.