Usually, the only reason whales come to the surface is to breathe. Humpbacks are capable of holding their breath for 45 minutes or longer, however, dives of this length are unusual.
Whales have very efficient lungs.
The size of a humpback's lungs also assists it's breathing capacity. The humpback whale's diet usually consists of microscopic zooplankton and small, shrimp like crustaceans called krill. When a humpback whale finds a school of fish, it swims through them and uses its lower jaw like a scoop. Social Structure Humpback whales are solitary animals. They travel in small groups that we call pods.