Answer:
The sonar sends a signal that travels at 1500 m/s. When the sound comes back to the ship it will have traveled to and from the object, it bounces off of. So depending on the time it takes to get back will dictate the depth/distance of the water.
Step-by-step explanation:
The device used by the ship's crew is called a sonar (short for sound navigation and ranging). The sonar sends out a pulse of sound waves (similar to the way a bat uses echolocation) that travel through the water and bounce off the seafloor. The sonar then detects the echoes and measures the time it takes for the sound waves to bounce back to the ship. Based on the time it takes for the sound waves to return, the sonar can calculate the depth of the water below the ship. The sonar is an important tool for ships to navigate safely in areas where the water depth may be variable or unknown.