 All whales have a thick layer of blubber . In species that live near the poles , the blubber can be as thick as 11 inches . This blubber can help with buoyancy ( which is helpful for a 100 @-@ ton whale ) , protection to some extent as predators would have a hard time getting through a thick layer of fat , and energy for fasting when migrating to the equator ; the primary usage for blubber is insulation from the harsh climate . It can constitute as much as 50 % of a whales body weight . Calves are born with only a thin layer of blubber , but some species compensate for this with thick lanugos . 
