No, otters do spend a lot of time in the water, but they also have four functioning legs. They come up on land for many reasons.
There are both freshwater (river otters) and salt water otters.
In the water
Otters are a semi-aquatic mammal. So they don't live exclusively in water.
Habitat destruction and water pollution are the main threats to otters.
sea otters excrete in water and on land
In the water
Fish
Sea otters typically do actually live near oceans. Not all otters however will always choose to live in the ocean.
Otters are able to stay underwater for up to 8 minutes.
alligators and water snakes
because there are nocturnal
they both like the water.