Underwater, whales do not have good vision. They have very good hearing, and use a system known as Echo location which utilizes a series of sounds and echoes to help them find their way and their food. Because whales travel in cold, icy waters, and can dive great depths, they need to keep warm. Under their skin is a very thick layer of Blubber. This acts as Thermal Insulation and also as a food storage.
Whales are strong powerful swimmers.
Their tail flukes are used to propel and steer them along, and their pectoral fins are used for twisting and turning in the water. Every year Baleen whales migrate to warmer water to mate, give birth and raise their young calves. Being air-breathing, baby whales are usually born tail first. It is important that as soon as they are born they reach the surface of the water to take in their first breath, otherwise they could drown. The mothers' milk is rich and high in fat content, and the calf gains weight and grows very quickly, as it learns to swim, search for food and communicate with others.