Tagging work off southern California recorded a Cuvier's beaked whale dive to about 2,992 metres in 2014, the deepest confirmed for any mammal. The longest is a separate record from a separate programme: a five-year study off Cape Hatteras, North Carolina, published in 2020, logged an individual submerged for 222 minutes, three hours and 42 minutes.
These numbers exceed the aerobic dive limit calculated from the species' body oxygen stores by a wide margin, which means the animal must be running substantially on anaerobic metabolism, tolerating lactate accumulation that would incapacitate most mammals. Beaked whales also carry adaptations shared across deep divers: collapsible lungs, high myoglobin concentrations in muscle, and profound bradycardia with blood shunted away from non-essential tissue.
The extreme records may not represent normal behaviour. The Cape Hatteras whale had been exposed to naval sonar shortly before its longest dive, and disturbance remains a candidate explanation for unusually extended submergence. Typical foraging dives for the species are much shorter, generally under an hour.