What is a sonar?

Sonar works by sending sound pulses through water and listening for their echoes after they bounce off objects or the seabed. It is widely used by submarines, ships, marine researchers, and rescue teams. Because sound travels faster and farther in water than light, sonar is extremely useful in underwater navigation and mapping. There are two main types: active sonar, which emits sound, and passive sonar, which listens for sounds made by other objects. Sonar has played an important role in naval history and ocean science.