Powerful tail flukes move up and down vertically to propel baleen whales through the water. Flukes are powered by muscle masses in the upper and lower regions of the tail stock. Rorquals, which are more streamlined than other baleen whale families, are known for attaining the fastest speeds of baleen whales. Other species travel at slower speeds. Baleen whales are not known to dive regularly to great depths.
Many species feed in relatively shallow areas of the continental shelf.
Dives last anywhere from 3 to 20 minutes or more depending on the species. All marine mammals have special physiological adaptations during a dive. These adaptations enable a baleen whale to conserve oxygen while underwater. Baleen whales, like other mammals, have a slower heart rate while diving. When diving, blood is shunted away from tissues tolerant of low oxygen levels toward the lungs, heart, and brain, where oxygen is needed.