What is the deepest diving mammal?

The deepest-diving mammal is Cuvier's beaked whale. This elusive toothed whale, also called Ziphius cavirostris, has repeatedly broken records tracked by satellite-linked tags and time-depth recorders.

In 2014, researchers recorded a Cuvier's beaked whale diving to 2,992 metres (9,816 feet) off the coast of California. A later observation documented a dive lasting 222 minutes, giving the species both the deepest and longest recorded mammal dives. These are extraordinary extremes, not necessarily the typical performance of every individual.

The whales hunt deep below the surface, probably pursuing squid and other prey. Their bodies are adapted for intense pressure and long periods without breathing: they conserve oxygen, slow their heart rate, and tolerate the effects of extreme depth. Sperm whales are also exceptional divers and can descend beyond 2,000 metres, but the documented depth record belongs to Cuvier's beaked whale.