 Beaked whales are often seen surfacing synchronously, but asynchronous surfacing has also been observed.In March 2014, a study by Cascadia Research revealed that beaked whales were recorded to dive at least 2992 m in depth and lasting as long as 137.5 minutes, both mammalian records (Cuvier's).Deep-diving mammals face a number of challenges related to extended breath-holding and hydrostatic pressure.