Which marine mammal holds the record for the deepest confirmed dive?

Cuvier's beaked whale holds the record for the deepest confirmed dive by a marine mammal.

A satellite-tagged individual reached approximately 2,992 metres in 2014, remaining underwater for more than two hours. This species has repeatedly produced extraordinary dive records, showing that some whales can tolerate immense pressure and very low oxygen levels.

Cuvier's beaked whales are medium-sized toothed whales found in deep waters worldwide. They feed mainly on squid and deep-sea fish, locating prey with echolocation. Their robust bodies and collapsible lungs help reduce problems caused by pressure changes.

Sperm whales also dive exceptionally deeply and are famous deep-diving mammals, but the confirmed depth record belongs to Cuvier's beaked whale. Individual records can change as tags improve, so the measurement refers specifically to the documented record rather than a claimed maximum.