Question

which instrument is used to see under water

Answer 1

Sonar is the name of instrument used to see and examine the object that are present under water.  

Sonar is solely creating use of an echo. As an animal or machine makes a noise, it transmits the sound waves into the setting around it. Those waves bounce off near objects, and a few of them mirror back to the item that created the noise.

Sonar is employed to seek out objects on very cheap of the ocean. facet scan navigational instrument is one technique wont to consider the detail of the seabed. facet scan navigational instrument instruments area unit towed behind ships and sometimes referred to as towfish or tow vehicles (shown below).

Sonar (originally an form for Sound Navigation And Ranging) could be a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, communicate with or observe objects on or beneath the surface of the water, like different vessels.