Most propulsion comes from alternate strokes of the hind flippers. Foreflippers also work with the hind flippers for maneuvering. Walruses generally breathe at the surface for about one minute after every five to eight minutes of subsurface activity. Walruses can remain submerged for as long as ten minutes. Deeper dives, however, have been documented.
All marine mammals have special physiological adaptations for diving.
These adaptations enable a walrus to conserve oxygen while it is below water. Walruses, like other mammals, slow their heartbeat while diving. When diving, blood is shunted away from tissues tolerant of low oxygen levels toward organs where oxygen is needed, such as the heart and brain. The muscle of walruses has a high content of the oxygen-binding protein myoglobin. Myoglobin transports and stores oxygen in muscle tissue.