Manatees behave rather like underwater cows. They are relatively harmless for such large animals, and swim individually or in groups of 15-20 in the sea, coastal lagoons and rivers. They will investigate any strange objects, including boats, by swimming up to them and peering short-sightedly at them - their eyesight is not good. When not feeding they rest at the surface with only their arched backs showing or, in shallow waters, they may 'stand' with the tail bent under the hind end of the body, and with the head and shoulders out of water. They sometimes 'walk' in shallow waters using the tips of their flippers to push them along the bottom. Adults use their tails to swim, using their flippers to turn, but babies swim with their flippers. They can remain underwater for 16 minutes so long as they are inactive, but usually they surface every 5-10 minutes to take 2 or 3 breaths.Read More: Foul-Tasting Mermaids!