Manatees are very agile and maneuver quite well underwater. Although manatees are excellent swimmers, the deepest an individual has been seen diving is 33 ft. They normally feed no deeper than about 10 ft.
All marine mammals have special physiological adaptations during a dive.
These adaptations enable a manatee to conserve oxygen while underwater. In contrast to whales and dolphins, manatees aren't deep-diving marine mammals. Therefore, manatees' muscles don't contain the high concentrations of the oxygen-binding protein myoglobin that is typical of other marine mammals. C. Respiration 1. While resting, manatees can stay underwater for as long as 20 minutes, although the average interval between breaths for resting manatees is two to three minutes.