Why do killer whales float?

A whale floats because of this type of fat called blubber. Blubber is basically the solid form of oil. For example : If you drop oil in water, then the oil will float. So since the whale has oil inside the body, the whale floats. Blubber, which is oil, is really thick in big mammals. The thickness is about 1 ft or more. Blubber makes whales float in water. :)