Echolocation

"Seeing" with sound is called echolocation. Echolocation helps an animal to navigate in water.

Dolphins can make sounds beyond the range of human hearing. This helps them to see detailed "pictures" of objects in the water.
A higher sound produces a more detailed "picture" of an object because the sound wave is shorter.
A lower sound travels further in water because the wave length is longer and can be used to detect distant or larger objects.