Otters spend most of their lives in the water, and they are made for it! Their sleek, streamlined bodies are perfect for diving and swimming. Otters also have long, slightly flattened tails that move sideways to propel them through the water, while their back feet act like rudders to steer. Almost all otters have webbed feet, some more webbed than others, and they can close off their ears and nose as they swim underwater. They like to swim on their back and sides and can see just as well underwater as they can above. Otters can stay submerged for five to eight minutes, depending on the species, because their heart rate slows to reserve oxygen.